Spark issues - TCCoA Forums
 
LinkBack Thread Tools
post #1 of 9 (permalink) Old 05-04-2008, 02:25 PM Thread Starter
Newbie
 
Join Date: Nov 2006
Location: saskatoon, sk
Posts: 7
Spark issues

I put new motocraft plugs and wires on my 92 SC for a tune up. Now it has a horrible miss under boost pressue above 8 psi. Plugs are gapped to. 054, and for sure all the wires are on tight. The car idles smooth and at 5000 rpm it runs good, its just at higher boost levels it does this. The car ran fine at higher boost levels before the tune up. The only mods to the car are a 10% od pulley on the s/c and a 255 fuel pump.

Any suggestions
88 LX is offline  
Sponsored Links
Advertisement
 
post #2 of 9 (permalink) Old 05-05-2008, 08:13 AM
 
Join Date: May 2005
Posts: 156
Quote:
Originally Posted by 88 LX View Post
I put new motocraft plugs and wires on my 92 SC for a tune up. Now it has a horrible miss under boost pressue above 8 psi. Plugs are gapped to. 054, and for sure all the wires are on tight. The car idles smooth and at 5000 rpm it runs good, its just at higher boost levels it does this. The car ran fine at higher boost levels before the tune up. The only mods to the car are a 10% od pulley on the s/c and a 255 fuel pump.

Any suggestions

As far as i can tell from what I have read at SCCoA, that gap is a little big. that is the MAX factory gap. Under higher boost levels they cannot hold up. I would try to gap them to like .040-.045 and see what happens. Here is a good thread that might helphttp://www.sccoa.com/forums/showthre...light=plug+gap
Robert M is offline  
post #3 of 9 (permalink) Old 05-05-2008, 08:48 AM
PostSlut
 
_95badbird's Avatar
 
Join Date: Jul 2004
Location: Spring Texas
Age: 39
Posts: 13,597
sounds like spark blow out.....regap them to .040.

Nick......................I'm back!!!
May you fly low and fast
rest in peace JL
_95badbird is offline  
Sponsored Links
Advertisement
 
post #4 of 9 (permalink) Old 05-05-2008, 10:56 AM Thread Starter
Newbie
 
Join Date: Nov 2006
Location: saskatoon, sk
Posts: 7
The old plugs were gapped to .054 when I put them in and I never had this problem. They were in there for 4 years, so i measured them and some of them had a gap of .061. Could a bad plug or wire cause my problem. My max pressure is 14 psi

Last edited by 88 LX; 05-05-2008 at 11:10 AM.
88 LX is offline  
post #5 of 9 (permalink) Old 05-05-2008, 11:41 AM
5th Gear Poster
 
Join Date: Jul 2002
Location: Ottawa,OH
Age: 39
Posts: 377
Send a message via AIM to rzimmerl
Change to your plugs Autolite 764's, and get rid of that 10% pulley. It is harming you more than doing good, because the IAT's are causing the knock sensor to retard the timing. You need to change to a cooler plug, the 764's effectively act like a cooler plug because they don't extend as far into the combustion chamber. If you want to go the next step switch to the Autolite 103 which is effectively 2 ranges colder. There is a FAQ on spark plugs on the SCCoA forums, check there for more data on this subject.

1990 SC AOD 1.7L AR....11.75 @118
441 RWHP 435 RWTQ
rzimmerl is offline  
post #6 of 9 (permalink) Old 05-05-2008, 10:00 PM Thread Starter
Newbie
 
Join Date: Nov 2006
Location: saskatoon, sk
Posts: 7
Thanks for the info, I'll try regapping the plugs first, then I'll try the different plugs and see what happens
88 LX is offline  
post #7 of 9 (permalink) Old 05-06-2008, 06:11 AM
5th Gear Poster
 
Join Date: Jul 2002
Location: Ottawa,OH
Age: 39
Posts: 377
Send a message via AIM to rzimmerl
regapping is going to be useless. You need to change the plug heat range.

1990 SC AOD 1.7L AR....11.75 @118
441 RWHP 435 RWTQ
rzimmerl is offline  
post #8 of 9 (permalink) Old 06-12-2008, 02:25 PM
 
Join Date: May 2008
Posts: 12
I was having the same problem, I placed new plugs in my 93 SC and it was missing at higher RPMs I pulled the plugs and they were all gaped at .045 so I gapped them at .054 like ford says. It now runs a little better but still missing some. If all the plugs are gapped at the same size I was told it would make a big difference.

So then I replaced the coil pack and it solved my issue, coil packs are $125 or $175 for the accel brand I went to the junk yard and found one for $25.

You also might want to take your DIS module off and remove the old thermal grease off it and replace it with a new coat, I use some arctic silver used on computer heat sinks. Good stuff.

I hope I helped,
Jerry V.
Cherry93SC is offline  
post #9 of 9 (permalink) Old 06-23-2008, 07:03 PM
 
Join Date: Dec 2004
Posts: 630
yea when i got my plugs from ford they had the same gap the 0.040 gap works fine
Destructor90 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the TCCoA Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome