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Car still misfiring

pippo

Member
105
7
18
Florida
People,

After replacing the ignition module recently car behaved strangely- when started (cold) as I run through the rpm's to accelerate, more noticeable in 3rd and 4th gear, when approaching 3000 to 4000 rpm car bucks/kicks severely, jerky like. I chased everything including ignition module checks (based on haynes manual), checked spark plug wires (water spray test, and resistivity), no stored codes.

BUT, after 2 miles or so, engine warmed up, problem goes away! I also checked Ohms on the coolant sensor, and it passed. Im gonna spend $10 and get a new one just in case, Ive tried everything. And $10 is nothing. What else can be related to engine performing better when warm? Any way to check the ECM?

Thanks!
 

pippo

Member
105
7
18
Florida
Yes, Mel. I know it looks like the finger shouyld be pointed to that, but it checks out voltage wise for the tests. It has a lifetime warranty, and I was thinking that I have nothing to lose by bringing it back ton AZ and try a new one. 2 cant be both bad (assuming the one i have now IS bad).
 

melsg5

Staff member
SUSTAINING MEMBER
19,442
67
48
Have you checked for a vacuum leak, cold engine requires a richer mixture than a warm engine.
Just noticed you had a previous thread where you stated the problem was resolved.
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pippo

Member
105
7
18
Florida
Have you checked for a vacuum leak, cold engine requires a richer mixture than a warm engine.
Just noticed you had a previous thread where you stated the problem was resolved.
Sorry for delay in replying, Mel. Just came back from out of town. I dont think I have a vac leak since I just did a head gasket and all appears sealed/tight. Not sure what you meant by how I resolved the problem from the quote from one of my posts- You mean when I had ther problem of a bad ignition module? I got a new one, and car started, but I think I did not explain it correctly then- the car still jerks badly, BUT only when cold. Anyway, having been out of town for 10 days, and just ran the car today to work, not I have an intermitten "serv car soon" light, goes on/off. I will check for codes.

Think my O2 sensor is fouled up from running a car that burns oil?
 

pippo

Member
105
7
18
Florida
Yup- just checked it and wow, a stored code showed code 22. Either TPS or Fuel cutoff relay circuit-open or shorted to ground. Now Im on to something. How do I check for the fuel cutoff relay circuit?
 

pippo

Member
105
7
18
Florida
Swap relays? Only relay i could find is one just about where the vapor canister is, mounted to the front corner of the car, about 1 foot behind the actual headlight door. But wheres the 2nd one? No other relay along the inside passenger side fender that looks like it would swap out (theres a bigger one where the 2 massive bunch of wires come together near that area, but wouldnt swap out, Im sure).

Meanwhile, tested the TPS and voltage checks out- 0.65v closed throttle, 4.5+ open throtttle. To me it is still a good TPS, right?
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92 Sunbird LE

Well-known member
1,982
29
48
Salinas, Puerto Rico
Relay for the fuel pump is near the back of the passenger strut tower, mine has 3 relays mounted there.

Your voltage looks good on you testing, try another tps to make sure it's a heat related problem and not wiring.

Doug in P.R. šŸ˜Ž
 

pippo

Member
105
7
18
Florida
Ohh, I get it now- switch the relay on the vapor canister with the fuel pump relay near top of firewall, drivers side. Maybe it IS fuel related. Will give it a try.......
 
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