'97 T-bird won't start - TCCoA Forums
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post #1 of 57 (permalink) Old 03-15-2016, 04:07 PM Thread Starter
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'97 T-bird won't start

Car: 1997 Ford Thunderbird 4.6L V8, pretty much loaded ~250,000 miles.

I just replaced the heater core - what a job. I removed the steering column and dashboard assy (there was no other way to get it done). I put it all back together (I think) and now the car will not run. The starter turns the engine over very well, just won't fire. The battery IS DEFINITELY good.

I'd like to think that I missed putting something back together, but I have searched high and low and all seems to be like it is supposed to be. It ran great before I did this.

The battery had been disconnected for a little over 2 weeks (I had to quit in the middle to wait on a 5-day monsoon to pass). The car has sat with a dead battery for almost a year before and it started right up then, so I can't imagine a ECM/PCM reset doing this. Am I wrong? Is there some kind of failsafe restart procedure?

Main question: Is there a fairly common mistake that people make doing a project like this might make, that I may have overlooked? Is there something that often gets broken during a job like this (inside dash or under hood - heater hoses were pretty difficult also).

I have not yet checked fuel pressure or ignition spark, but they are going to be first check. I did try pushing the schrader valve in the fuel runner port and there was a little pressure and gas squirt after every time I tried cranking, so I THINK the fuel pump is working.

Back in the day of non-computer-controlled carburetors, I could troubleshoot and fix almost anything, but these things are just too difficult. I feel lost.

Please advise?

~ It's later than you think (if you think it's earlier than it really is).
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post #2 of 57 (permalink) Old 03-15-2016, 06:13 PM Thread Starter
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PM Update: For any wonderful person so inclined to weigh in on this, I have this update. It is definitely fuel supply related - there is no fuel pressure coming in to the fuel pressure regulator. I can only guess what "burping" I saw previously when pressing the schrader valve between start attempts was really a minimal pressure building up in the fuel rails due to residual fuel in the fuel rails. When I removed the fuel pressure regulator and observed the fuel inlet during a start attempt, there was no fuel spewing out.

Now, I am looking to see if problem is electrical or mechanical. I have checked the fuel shut-off relay in the trunk and it is reset OK. Also, fuses are OK. Haven't found the fuel pump relay yet.

Is there anything under the dash or in the steering column that I could have forgotten to reconnect that could disable the fuel pump? how about engine compartment around the heater hoses?

~ It's later than you think (if you think it's earlier than it really is).
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post #3 of 57 (permalink) Old 03-15-2016, 06:28 PM
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Check your crankshaft position sensor.
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post #4 of 57 (permalink) Old 03-15-2016, 09:40 PM
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Check your other topic.

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post #5 of 57 (permalink) Old 03-16-2016, 12:59 AM
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The fuel pump relay is in the Constant Control Relay Module, (CCRM). This "box" is located in front of the air filter box.

Here is a link that is a good description of the CCRM.

http://forums.tccoa.com/17-audio-ele...d-lx-4-6l.html

The relays can be probed with a test light for proper operation while remaining in service.
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post #6 of 57 (permalink) Old 03-16-2016, 03:08 PM Thread Starter
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I was wondering about the CCRM. I did find it behind the air filter on tthe radiator support. Thanks for the link to a little insight on this module - I checked and 1996-1997 Tbirds use same module.

So, is there another relay outboard of this module before the fuel pump in the tank, or does the output of this module connect directly to the fuel pump? Exactly where does the inertia shutoff relay figure into this? I can't seem to find a decent wiring diagram for all this in any of the 3 service manuals I have. If I can trace the supply voltage to the fuel pump, I can figure this out...


What I am struggling with is whether something spontaneously failied during the 2 weeks that I had the battery disconnected (or maybe failed during battery reconnection) or did I break or forget to connect something back up when I took the dash out... ???

~ It's later than you think (if you think it's earlier than it really is).
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post #7 of 57 (permalink) Old 03-16-2016, 04:10 PM
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Quote:
Originally Posted by CPO_daddyduke View Post
I was wondering about the CCRM. I did find it behind the air filter on tthe radiator support. Thanks for the link to a little insight on this module - I checked and 1996-1997 Tbirds use same module.

So, is there another relay outboard of this module before the fuel pump in the tank, or does the output of this module connect directly to the fuel pump? Exactly where does the inertia shutoff relay figure into this? I can't seem to find a decent wiring diagram for all this in any of the 3 service manuals I have. If I can trace the supply voltage to the fuel pump, I can figure this out...


What I am struggling with is whether something spontaneously failied during the 2 weeks that I had the battery disconnected (or maybe failed during battery reconnection) or did I break or forget to connect something back up when I took the dash out... ???
Being a nearly 20 year old car, it is entirely possible that one sensor may just "go" after not being used awhile.

That said, I'd retrace my steps and double check all connections. Make sure the PCM is fully plugged in, etc.
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post #8 of 57 (permalink) Old 03-16-2016, 04:51 PM Thread Starter
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I found a couple more resources that may help me figure how it all works and what connects to what:
http://www.askatech.com/askatechlive...track/f093.pdf
http://www.justanswer.com/ford/29mv8...6l-cranks.html

I still need to determine if problem is electrical or mechanical, but the more I can learn about how it is "supposed" to work, the easier that will be.

Thanks for your input.

~ It's later than you think (if you think it's earlier than it really is).
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post #9 of 57 (permalink) Old 03-16-2016, 04:53 PM Thread Starter
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I put a couple of links in my previous post but they got blanked out - how do I overcome that. I'm thinking those links may be useful to someone else...

~ It's later than you think (if you think it's earlier than it really is).
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post #10 of 57 (permalink) Old 03-16-2016, 05:05 PM
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Quote:
Originally Posted by CPO_daddyduke View Post
I put a couple of links in my previous post but they got blanked out - how do I overcome that. I'm thinking those links may be useful to someone else...
I see the links.
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post #11 of 57 (permalink) Old 03-16-2016, 07:54 PM Thread Starter
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Update: I now know that I am not getting 12VDC to the fuel pump (i.e., the pump is not running at all). I have traced it to the CCRM - the output signal on pin 5 of the CCRM is nothing, no matter what the condition of the ignition key. I checked some of the input signals from the ECM/PCM to the CCRM - pin 12/24 is nothing (don't know what it should be), pin 11 is good 12VDC, pin 18 seems to float around 10-50 millivolts as if it were open. So I'm thinking maybe I knocked the PCM connector loose, but no, it seems to be plenty tight connected and all the cable connections that were undone during dash removal were correctly connected.

It got a little dark on me, I've got some more tracing to do.
I could sure use a complete schematic right now, haven't been able to find one.
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post #12 of 57 (permalink) Old 03-16-2016, 08:39 PM
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Quote:
Originally Posted by CPO_daddyduke View Post
Update: I now know that I am not getting 12VDC to the fuel pump (i.e., the pump is not running at all). I have traced it to the CCRM - the output signal on pin 5 of the CCRM is nothing, no matter what the condition of the ignition key. I checked some of the input signals from the ECM/PCM to the CCRM - pin 12/24 is nothing (don't know what it should be), pin 11 is good 12VDC, pin 18 seems to float around 10-50 millivolts as if it were open. So I'm thinking maybe I knocked the PCM connector loose, but no, it seems to be plenty tight connected and all the cable connections that were undone during dash removal were correctly connected.

It got a little dark on me, I've got some more tracing to do.
I could sure use a complete schematic right now, haven't been able to find one.
Here is the MN-12 "bible". Full Ford service manual and the EVTM.
https://www.dropbox.com/sh/ghc1zorwt...SNV930yea?dl=0
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post #13 of 57 (permalink) Old 03-16-2016, 09:42 PM
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From the sticky in the Newbie Forum: http://forums.tccoa.com/5-newbie-for...acronymns.html

VMM = Vehicle Maintenance Monitor. Shows you if you have low fuel, low coolant, a door ajar, and for some if the firm ride is on but only for vehicles equipped with a VMM. Some VMM's have a button to turn the Traction Control off too.

I have the EVTM (Electrical and Vacuum Troubleshooting Manual) for the 95 and the wire colors shouldn't be much different.

The 13FL fuse in the Power Distribution Box sends power to the CCRM (aka IRCM) by way of the BK/Y wire. The CCRM sends 2 wires (PK/BK and LB/O) to the PCM but the PK/BK wire is the one that also goes to the Inertia Fuel Shutoff Switch in the trunk. Then it's a DG/Y wire from there to the fuel pump.
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post #14 of 57 (permalink) Old 03-17-2016, 12:29 PM Thread Starter
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Originally Posted by Woodman View Post
Here is the MN-12 "bible". Full Ford service manual and the EVTM.
https://www.dropbox.com/sh/ghc1zorwt...SNV930yea?dl=0
Thanks loads & loads & loads for tthe docs - tthis will help tremendously. I already had the volumn 2 of the factory service manual (I love also having in softcopy - easier to search), but none of the electrical diagrams, Thanks again.

Thanks again.
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post #15 of 57 (permalink) Old 03-17-2016, 01:28 PM
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Originally Posted by CPO_daddyduke View Post
Thanks loads & loads & loads for tthe docs - tthis will help tremendously. I already had the volumn 2 of the factory service manual (I love also having in softcopy - easier to search), but none of the electrical diagrams, Thanks again.

Thanks again.
Happy to help. I tend to print off what I need before going out to the garage to work. Eventually I'll have the whole thing on hardcopy..
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post #16 of 57 (permalink) Old 03-17-2016, 03:43 PM Thread Starter
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I tend to print off what I need before going out to the garage to work.
I do the same. Thanks again.

BTW, I have attached a pic of the inside of my CCRM. I still have not determined for sure if it is bad, I like to make sure the input signals are OK before buying a >$100 part.
Attached Images
File Type: jpg CCRM Inside 2.JPG (518.1 KB, 3 views)
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post #17 of 57 (permalink) Old 03-17-2016, 06:49 PM Thread Starter
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Originally Posted by rushtonracing View Post
The fuel pump relay is in the Constant Control Relay Module, (CCRM). This "box" is located in front of the air filter box.
Here is a link that is a good description of the CCRM.
http://forums.tccoa.com/17-audio-ele...d-lx-4-6l.html
I was thinking that 96 and 97 CCRM boxes were same, but mine has one more relay in it besides the one shown in tthe "...ccrm-detail-1996-tbird..." document. Perhaps they are still the same, but one has an electronic switch while mine has a mechanical relay. (??)

===============================

I am trying to understand the theory of operation to accurately troubleshoot this thing (I must be sure, I cannot afford to buy a $100 box just to test with). According to my understanding of the Operation Description in the factory service manual section 03, there are two different sources of +12V that are "wire-or'ed" to the fuel pump. One comes from pin 40 of the PCM and the other from pin 5 of the CCRM. I think PCM pin 40 provides +12V for about 1-sec when key is first put in RUN (for charging the injector rails) and CCRM pin 5 provides +12V during START and when engine is running. The CCRM pin 18 receives a ground signal from PCM pin 80 that energizes the FP relay in the CCRM. I think...

What I don't know is if there are any failsafes built in that shut things down if there's a short or some anomoly. Supposedly, the diagnostic procedures for this are located in a "Powertrain Control/Emissions Diagnosis Manual" that I don't have. Anybody know where I could get one or portions of it?

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post #18 of 57 (permalink) Old 03-17-2016, 09:28 PM
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The only safety cutoff I can think of is where if there is a short going to the PCM it won't turn on. You would know this was the case if your engine fan turns on the second you turn the key to ON. If your fan is functioning normally I would assume the PCM relay is fine but the fuel pump relay may not be fine. You could always try using a jumper wire to see if the fuel pump engages from the CCRM harness.
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post #19 of 57 (permalink) Old 03-18-2016, 12:05 PM Thread Starter
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This thing is driving me out of my cotton-picking mind. I am gradually becoming less suspicious of the CCRM and more suspicious of the PCM itself.

I can feel relays tripping when turning car ON (feels like multiple but can't tell which ones; vibrations travel throughout board).
I never see a ground being applied by the PCM to energize the FP relay in the CCRM during START; I never see the 1-second +12V pulse from tthe PCM to the fuel pump; at least, I think these are what I should expect.

Quote:
Originally Posted by V8ThunderCat View Post
... the PCM it won't turn on. You would know this was the case if your engine fan turns on the second you turn the key to ON. ...
The rad fan does come on instantly and runs at low speed when car is turned ON (I don't remember it ever doing that before, but I could be wrong). It does turn off when key turned off.

I tried hooking my scan tool up to the diagnostic port just to see if there might be anything that might tell something, and it would not communicate with the computer - it powered up, but returned a "failure to communicate" shortly after turning car on. hhhmmm...

Quote:
Originally Posted by V8ThunderCat View Post
... try using a jumper wire to see if the fuel pump engages from the CCRM harness. ...
I did try forcing +12V onto the CCRM FP relay output and the fuel pump did run;, next I'll try forcing the ground on the input to the CCRM FP relay to see if it really does energize - I am going to check a few more things as soon as threat of rain showers goes away.

~ It's later than you think (if you think it's earlier than it really is).

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post #20 of 57 (permalink) Old 03-18-2016, 03:44 PM Thread Starter
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OK - I am reasonably certain that the PCM (or ECM) is defective or is not working (or not connected?).

I rechecked all the voltages going into the CCRM and they are good (HAT & HRS, good). I checked to make sure the CCRM Pwr Relay was working (+12V at CCRM pins 12 & 24, pwr to PCM and other relays in CCRM, good).

Still the FP signal from PCM pin 80 to FP Relay in CCRM never goes low (not even for 1 second when car first turned ON/RUN nor during START). BTW, I think I have a better understanding of how it should work and my previous understanding was in error - all fuel pump control is thru this input and the connection back to the PCM pin 40 is a FP monitor, not another FP enable.

I tested by manually connecting a ground to the FP Relay control input of the CCRM (pin 18, LB/O wire), and it worked: the fuel pump ran OK.

I checked spark (spark tester) and injector signals (noid light) and nothing/nada/zip/diddly squat during START (sure could be caused by other things, but what are chances ...).

I rechecked with my scantool and again it would not link/communicate with vehicle.

Sounds like PCM/ECM for sure. I have checked all fuses that go to PCM circuits - none blown.

Any other thoughts?

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post #21 of 57 (permalink) Old 03-19-2016, 03:59 AM
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True, you could have a bad PCM but you could still have a short like mine. For me it was the wiring that goes to the DPFE sensor having been melted by the EGR tube. To find that short it could involve dumb luck like when I washed my engine the last time or tirelessly checking every wire going to and from the PCM. I had tried multiple PCMs from the junkyard which helped me rule that out.
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post #22 of 57 (permalink) Old 03-19-2016, 11:05 AM Thread Starter
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... but you could still have a short ..., wiring that goes to the DPFE sensor having been melted by the EGR tube. ...
So where is this DPFE sensor located? I am thinking how tight it was getting the new heater hoses on and wondering what I might have bent/broken/squashed or whatever while pushing and shoving with my hands where I could not see there at the back of the engine. There were some tubes & wires back there that I could not really see well.

Since I don't have a lot of experience with troubleshooting automotive-specific electronics, I still want to wonder what kind of sensor malfunction could make the PCM go completely dead (or at least appear that way)?

Since I don't know exactly what else to do right now, I plan to go ahead and remove the PCM, hoping that some dumb luck might reveal that I had broken or disconnected something when I removed/replaced the dashboard.

But still looking for advice (and some diagnostic procedures)...

~ It's later than you think (if you think it's earlier than it really is).
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post #23 of 57 (permalink) Old 03-20-2016, 02:02 AM
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The DPFE sensor is on a bracket off the back of the passenger head. Well, I think it is. I wasn't able to get mine into that spot after I did the intake upgrade because of short hoses. Anyway, the original sensor would be made of aluminum and has 2 hoses going to it along with 3 wires. The hoses connect to the EGR tube and the wiring has a habit of getting melted by the tube. It's worth checking out. If you have a newer sensor it would be made of black plastic instead. A bad sensor also typically causes a rough idle and doesn't always throw a CEL.
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post #24 of 57 (permalink) Old 03-20-2016, 09:07 AM
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This is a very common failure for these cars! IT happened to me. The wires melted all the insulation away, and would touch frequently.

Symptoms are fan always running when it is in the run position, and no SES light on.

I found that if I did a "pull" test (much more than a wiggle test) of the main harness, the fan would stop running and I could start the car, but then while driving I would hit a bump or go around a corner and it would die.

I dug into the harness and found 2 wires with 2 inches of insulation burned away. I somehow (this was 2005) insulated them and all was good from then on.

I THINK that the wires come out of the main harness around where that small black plastic zip tie are on this picture. The DPFE is that silver box on the back of the passenger head above the EGR tube.
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post #25 of 57 (permalink) Old 03-20-2016, 04:58 PM
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Quote:
Originally Posted by CPO_Daddyduke
I am reasonably certain that the PCM (or ECM) is defective or is not working (or not connected?).
Check PCM ground connection(s) from body to PCM. As we know the PCM creates the ground to many components. So the PCM itself must have the best of all grounds with the least of resistance. A really good ground.

I write this mostly because the no-start occurred after the work done under dash.

You can also take your old PCM to a parts store, and some can test it. Before it is condemned.
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post #26 of 57 (permalink) Old 03-21-2016, 07:05 PM Thread Starter
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the wires come out of the main harness around where that small black plastic zip tie are on this picture. The DPFE is that silver box on the back of the passenger head ...
This an area I am concerned about anyway as I had a buggar of a time pushing and shoving trying to get the new heater hoses. I'll be taking a close look here....

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post #27 of 57 (permalink) Old 03-21-2016, 07:11 PM Thread Starter
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Check PCM ground connection(s) from body to PCM. As we know the PCM creates the ground to many components. ... You can also take your old PCM to a parts store, and some can test it. Before it is condemned.
This I know, as well - and certainly this is where I am now; all I can think of to do is to crawl back up under the dash and ring out as much of the wiring to/from the PCM as is humanly possible. Voltages and Vref, too. Something must be amiss. I am remembering that I also removed an old aftermarket module that had been installed many years ago that was part of a CD Changer system (maybe I clipped one too many wires).

I did not know that some parts houses had the capability to check out those PCMs - Can you recommend one (e.g., AutoZone)? Might be worth taking it there straight away; results would tell me where to spend my energy.

~ It's later than you think (if you think it's earlier than it really is).
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post #28 of 57 (permalink) Old 03-22-2016, 08:35 AM
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I have a ' 94 4.6 V-8 that I will never part with...that being said...it also has issues and I'm a diy-er although I believe that sometimes the most valuable skill is knowing my ACTUAL abilities as opposed to EGO abilities..and have no shame in leaving some things to the pro's...I just watch, learn and maybe expand my knowledge a little..my dad raced cars when i was little and I LOVE all of it...ESPECIALLY AMERICAN MUSCLE!!!
That being said...I also have an issue with the lack of any schematic that is what I need when I need it. Regardless of a plethora of manuals that will dānce āll around ānd i get nowhere FAST! I'm brāinstorming for you if you still need ideas.
My intent in posting unfortunately is only to commiserāte. Sorry. I also have found a couple helpful site's if you are interested I will text to you.

I LOVE MY BIRD! 22 Yrs old but I will say this... I GOT YOUR GRANNY-CAR...RIGHT HERE! WOO-HOOOO!
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post #29 of 57 (permalink) Old 03-22-2016, 09:33 AM
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Also, I know what it takes to do the heater core yourself and when I say what I'm gonna sāy it is only for context...not smart-ass or know-it-āll...
There are ān infinite number of variables ānd incidental snaffu's that its reālly not likely to know without repeating job, which you still can as last result.so here's my thoughts...it seems more likely thāt its just random of was just a random timing issue and they are unrelated. Was heater core job successful or is it not known due to other issue? No fuel is a pretty limited number of causes..Maybe there is no gas in tank..lol! Fuel filter?Fuse? Injection clogged? Sorry not being smart ass...maybe fuel line broken or clogged.
My advice is to systematically elimināte other possibilities CHEAPEST AND SIMPLEST AT TOP OF LIST! DRASTIC WILL STILL BE AVAILABLE AFTER! Sorry if I rambled or came off in negative manner. I hope it helps.. Let me know if you fix it or need ideas or whatever.
Schmellfiscy
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post #30 of 57 (permalink) Old 03-23-2016, 01:14 PM Thread Starter
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Originally Posted by schmellfischy View Post
... systematically elimināte other possibilities ...
First, any and all suggestions are welcome. If I may say, this DIY project is much more necessity than ego - I really do like the car (I have owned it since it was new), but I am on very limited income (small pension and social security) with a lot of expenses (wife is battling cancer). This is only car I have with working A/C and it has some other new parts and has been very reliable. I am a relic of the 1960s muscle car era (have a '68 Barracuda) - I have a lot of experience working on cars/engines, but before the computerized era. I am also a retired electronics engineer, so I know embedded computers inside/out (in general, not automotive specific), but the lack of comprehensive/exhaustive documentation and x-ray vision is a real limiting factor. It would also help if I was much smaller and could fit into all these nooks and crannies where things are.

If I may reiterate, I am still pretty sure the PCM is inoperative, although I can't prove it is defective, yet.
Just to review and get back on level footing, here is a list of what I think are the relavent symptoms (most already stated, some new):

1. When key/ign is first turned ON (engine OFF, and in START), there is no CEL/SES/MIL light on instrument cluster. There should be.

2. With my Innova 3040 scan tool plugged in to DLC or Diag Port, it lights up (getting power) but when key is turned to ON, it attempts to link with computer but cannot - after a few seconds, it returns a "failure to communicate" error. PCM must not be online.

3. While cranking, there is no fuel, spark, or injector pulses. I only traced the fuel pump enable signal back to the output of the PCM; if I ground this signal, the fuel pump runs and fuel flows plentifully to the rails and out the pressure test port. PCM does not seem to be generating any signals needed to run the engine (at least in the case of fuel supply, everything downstream is working properly).

4. I have checked and there is an EEC power signal (+12V) coming out of the CCRM going to power the PCM. I have checked all fuses and they are all good.

(I didn't see the need to further trace the ignition/injector problem, since it seemed at this point that some kind of PCM failure was evident.)

5. When key/ign is first turned ON (enhine OFF, and in START), engine fan comes on and runs at low speed. No shutoff signal from PCM.

Now, I am basically just ringing out all the wiring to/from the PCM (looking for a fault that is disabling the PCM or that may have damaged the PCM; this is only reason I haven't just bought a new one to test with). If it's an open ground or something like that, hopefully it will be easy to find. I am hoping that I may still find something that I messed up when I had the dashboard out.

I am looking for some place to take the PCM to have it tested - that knowledge would help me know where to concentrate my efforts. But I haven't any place that has the equipment to test PCMs.

The biggest thing that would help me right now (I think), would be a list of signals and sensors that connect to the PCM and what kind of reading would be expected in a static state. I could probably create a signal list from the documentation I have, but I don't have a pre-existing comprehensive understanding of the mechanics/electronics behind every single sensor on the vehicle.

Again, if it looks like there is something I've overlooked, please mention it. Any ideas, even shots in the dark, are welcome.

~ It's later than you think (if you think it's earlier than it really is).

Last edited by CPO_daddyduke; 03-29-2016 at 08:33 PM. Reason: added #5.
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