cars runninin rough!

tbird79

Registered User
I have a 90 tbird sc, havent had any probs with it, last nite i was just driving along and all the sudden its really running rough not to bad when idling, but when u accellerate its really rough feeling. Did new plugs and wires 2 weeks ago, it really feels like its missing to me the engine is shaking. I hooked up the code reader and the only code i got was code 21 cooling temperature sensor or ect out of range. Not really sure what thats all about. And i (without alot of effort) made sure the wires were attached well. Any ideas? Maye take a better look to make sure wires are on properly?

Thanks for any help!
Joe
 
I just thought of this. I'll bet that one of your plugs or wires is defective. I have gotten a plug before that was so bad that it wouldn't even spark at all.
 
ewww

Ewww i hope not i dont feel like doin that job again! Do you think the chances are it could be a bad plug. They are motorcraft double plats, and new stock wires.
 
Couldnt find any vacuum leaks, all the wires are connected properly, and still same problem, idles a little rough like it is missing, but as soon as u go to to accelerate the engine seems to miss really badly. Im kind of at a loss.

Thanks again
Joe
 
what I do is this. I pull one wire at a time. (Pull it and then put it back on before going to the next one of course). When/if I pull a plug wire off the coil pack, and there is no change in how the car is running, then I know that there is probably a problem with either that plug or wire. If the car runs worse, then you know that that plug and wire are operating fine. Motorcraft double platinums are a good choice, they are what I use, but no-matter how good the plug, there are always a few that don't work but still make it out onto the shelves.
 
Glad i'm not the only one

tbird79,
I just replaced my plugs because I was having allot of detonation and thought they might be screwed. When I put the new plugs in (motorcraft AWSF 34PP gapped to .054) the car ran just like you described. I should also mention that I dropped down to a 70mm TB and stock MAFS. I got pissed off and put the old plugs back in and 85mm TB and 76mm MAFS and same result. You, me, and one other person on this forum all reported the same thing. I have been told it is the wires and I went ahead and ordered new ones. The other thing I will look into when the wires get here is sealing up the TB good when I put it back on. The manual says there could be a vacume leak there causing the problem. Good news for me is I can change the plugs in 30 minutes now. One more thing, I was told to gap to .052 to allow for wear of the electrode and be really careful (if you can) not to hit the plug when putting it in so not to screw up the gap. Good luck and I will let you know if my wires helped.
 
yes, that is a good point. Be careful not to undergap the plugs. te motorcraft shouldn't be gapped below .047, I set mine to .048
 
Motor mounts are a long shot and dont go overnight but many a rough running motor are cured with new ones. If you have replaced yours, one less thing to worry about. Good luck
 
I would pull each plug individually and check for spark with an extra plug.

If you are sure it isn't ignition related I would say it is probably 1 or more dirty fuel injectors.

Good Luck...
 
does it feel like its running on 4 cylinders? if thats the case, i had the same problem with mine. i thought it was the spark plugs, didnt help, plug wires, didnt help, then i went to the coil....yeah right....finally with my last 150 someodd dollars i had left, i went a bought a DIS. cured the problem, and i have a brand new ignition system, pretty much....i dont know if this will help you out, just a suggestion...i did the whole pulling plug wires from the coil on my old coil pack, and found 2 plugs werent firing at all, thats why i replaced the coil. the new coil did the same thing, so thats when deductive reasoning came in and i replaced the DIS. good luck.
 
tbird79

Have you solved your problem yet. I have been under the hood of my car for 2 weeks with the same problem and havn't firgured it out yet. I have replaced plugs, wires, mixed and matched, switched TB's and MAF's because it pulled 2 codes for running lean, and still have not got it fixed. So I am off to the stealership on monday to pay them $110 just for them to look at it and probably B.S. me on what is wrong. If you found anything please let me know. Thanks.
 
problem solved

Too it to the dealership. To have a diagnosis, turned out the fuel pump we gettin quite weak. I took it home put in a new pump and filter, and its as good as new.
 
Mine is going to the dealer on monday. I had a fuel pressure test done on the car and at idle I am getting 32psi. I think my pump might be bad, the fuel filter is brand new.
 
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