after tune up... big problem

[TL8apxrx7]

CASE CLOSED... FIXED!!!!

I have searched for 2 days now about this issue and haven't found a fix.

I recently performed a tune up (O2 sensor, oil change, fuel and air filter, plugs, etc...) and when I started my engine it runs like crap. Constant misfire and backfire, no power and sounds like an old subaru with no exhaust.

I have checked my plug wires many times and they are in properly. I have found no vacuum leaks and all my plugs and hoses are attached. I tried to pull codes and am getting nothing from tests.

What am I missing? It ran beautifully before the work, even with the old plugs having a HUGE gap (.062).

I'm about to pull the intake/snakes again to see what may have happened upon reassembly. Suggestions please???

 

[93rev2sev]

Check the fireing order again. specifically the back row. Make sure to use the information in the sticky on firing order located on this forum's main page.

The information in the chiltons(and others) manual is wrong. Period.

Here's the thread...

http://www.shoforum.com/showthread.php?t=89091

 

[Phoenix]

Refer to this :

Backfires are usually a timing and incorrect wirering issue.

 

[TL8apxrx7]

firing order...

this is the order I am using...

firewall
123
456
front

coil

rear
51
62
43
front

followed the info from this site.... I don't trust any other source for my SHO

 

[shoclown]

are the wires new? i have had wires start misfiring after i removed them ( must have been brittle and broken inside) the ford spec is 8000 ohms per foot. check them with a dvom

 

[sho2see]

did you check to see the wires are seated tight on the plugs?

 

[TL8apxrx7]

wires

the wires are new and are seated nice and tight... hopefully no problem there....

 

[93rev2sev]

check the order again or start swapping coils and DIS modules...

Also, make sure the intake manifold is securely GROUNDED to the chassis and that the left rear inner intake corner bracket(crossover tube hold down) is bolted together.

 

[TL8apxrx7]

ground wire

there was a ground wire on the left side and I made sure it was attached...

I have gone over this thing over and over... I am very **** about doing repairs and I know I didn't miss anything...

also I put a timing light on and the mark is not at 10 degrees... without a distributor to adjust I don't know what to do about that

 

[93rev2sev]

in your original post, you mentioned that you did plugs but did not mention wires.

Please define "etc.." as used in your original post.

If you are re-using the wires, I'm guessing one or more of them got damaged when removed.

 

[TL8apxrx7]

yes the wires are the old ones due to the fact that they had to be ordered and will not be here for a few days... how do I check the wire without pulling the whole thing apart? its raining now and I don't want to pull the intake and get stuff wet

 

[93rev2sev]

There is absolutely no need to pull the intake to remove the wires.

 

[TL8apxrx7]

thats what I thought... main reason why I did the plugs and will wait for the wires... so pull them and check for spark one at a time?

 

[93rev2sev]

Well the drop dead easy thing to do is run the car and start pulling wires one at a time until you pull one and nothing changes...that's your dead wire.

Make sure to insulate the crap out of yourself...and wait till you aren't standing barefoot in rain water...I won't be responsible for your heart stopping.

 

[TL8apxrx7]

will do... it stopped raining for the moment so I'll go do that quick

hehe... I almost thought you said to stand barefoot in rain water... had to read that again really slow... hehe...

 

[TL8apxrx7]

well I don't know what I did but I started pulling wires off the coil pack and when I got to #5 I pulled it and nothing changed but when I plugged it back in it smoothed out and is running fine now...

I pushed and pulled on all the wires so many times yesterday I don't know what the heck happened... its all good now

consider this case closed and thank you all for the advice. you all are amazing at helping people with their cars and you are all much appreciated. keep up the great work. you guys are the authority on the SHO!!!!

 

[93rev2sev]

+1 for the good ol' wiggle test.

 

[TL8apxrx7]

yes, one of the most important tests!!! thank you so much!!!!