I almost give up...

[Ger-Fire-Form-93]

Hi guys,
After replacing a total rusty Opti, ignition wires, coil, Iac and oxigen sensors, the hesitation still there.
But only when the engine gets warm.
When its cold runs fine.
I dont know......my last shot will be replacing the ignition module.
any suggestions?
Thanks in advance.

93 Formula,A4.

[Trash man]

something sounds like its gettin heat soak. when does it happen? going from light to WOT?

[94 formula]

What kind of plugs do you have in the car?

[Ger-Fire-Form-93]

Am using TR55 spark plugs.
And the hesitation goes from idle 950 to 1200 rpm.

[Christopherrr]

Am using TR55 spark plugs.
And the hesitation goes from idle 950 to 1200 rpm.

you gap em?

[fastTa]

you gap em?

Did you replace them?

Could be the ICM getting heat soaked....a common problem.

Get it on a scanner and see what's going on.

[Ger-Fire-Form-93]

Did you replace them?

Could be the ICM getting heat soaked....a common problem.

Get it on a scanner and see what's going on.

Yes I did, everythig together. Ngk TR55 @ 50.

Should I replace the ICM too??

I get no codes in my scantool.

thanks for your inputs.

[Craig 94 TA GT]

A laptop and scan software would work best IMHO. Datamaster records everything, so you can see your BLMs, O2 readings, etc. That is what Kevin (FastTA) is talking about.

Regarding your hesitation, how bad is it? Does it only occur when accelerating from a dead stop?

I had a very, very annoying low end stumble/hesitation. It would only occur during closed loop (fully warmed up), and accelerating from a dead stop. I tried everything which included: new opti, coil, ICM, plugs, wires, injectors, fuel pump + filter, valve springs + seals, rockers, lifters, ICM/coil spacing, and fixed intake oil leak, and still had the stumble/hesisation. I could not figure it out, and the PCM readings showed OK. I finally ditched the crappy manifolds (had an exhaust leak) for SLP headers (still has a slight leak), and the stumble was finally gone. It disappeared and never came back. I have no idea why, since I still do have an exhaust leak. It could be due to cutting down on the severity of the exhaust leak, or it could have been that my LT1 didn't like the crappy manifolds.

I don't know if yours is the same problem though