0351 Code & Rough Idle- After TB Change

[mharrison]

OK I have 97 Eclipse 420A NT. TB broke and bent some valves.

Had head reworked. Replaced all the belts, hoses, idler, water pump, tensioner etc.

After putting it back together it starts and runs, but it has a rough idle and I have a CEL with P0351 - Ignition Coil A Primary/Secondary Circuit Malfunction

I pulled each plug in turn and it ran worse when each was pulled, so no dead miss.

I hate to ask, but is this normal behaviour for an engine that is one tooth off on the Timing Belt?

Please tell me no and then tell me how to fix this!

It starts fine. It idles pretty badly, but will hold an idle. It runs great when you're on the throttle, but when you slow down for a light or stop sign from speed it dies if you don't heel\toe it and feed it some gas.

 

[DSMcrazy3]

..Is your timing off one tooth? Check this first as it could easily cause this problem. If that checks out fine, and the connector to your coil pack is fine, replace the pack.

 

[BLACKpsiECLIPSE]

I would deffently check the timing, one tooth is alot more then you think.

 

[mharrison]

If I wasn't getting an ignition code then I'd have already moved on to checking the timing.

What is the best way to find TDC without being able to see the mark behing the crank pulley?
If I can get it to TDC and open the little window on the Timing belt cover this will be easy.

The code just kept me from pursuing the timing since I didn't understand why it would throw that code due to the timing being off. (And I really didn't want to have to mess with the timing again!)

 

[mharrison]

Has anybody got a magic trick or tip for adjusting the timing by one tooth?

That would be handy if that turns out to be the problem.

 

[DSMcrazy3]

Your car is run by the timing man. One tooth can throw everything out of whack. When one signal is sent, another is sent, and another and another and another and another and I could go on and on. One signal being sent at the wrong time throws all the other signals off. Those pistons are moving fast, even at idle. That spark needs to happen at the correct time. With the piston in the right spot to get sufficient combustion. When it's off, you get misfire, and rough idle. It could very well be the cause of this CEL.

What makes you wonder if your timing is off by 1 tooth though?

 

[mharrison]

What makes you wonder if your timing is off by 1 tooth though?

Because I just put a timing belt on. I had a hard time getting the timing set correctly, but after I did, I turned the engine over several times and rechecked it. So if it is off, I would think it was only by 1 tooth (although honestly I think it is right. All looked good. But given all the trouble I had, now I have my doubts.

 

[BLACKpsiECLIPSE]

take out your spark plug in cylinder #1 put a long screwdrive in it and rotate the crank by hand until the piston is at TDC right before it begins to go back down. then check your timing marks, see if there aligned. after that we can rule that out and move to something else.