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Fuel cut out - Stumbling when coming off boost Posted by VC_saab [Email] (#142) [Profile/Gallery] (more from VC_saab) on Sat, 8 Apr 2017 20:48:33 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Hi, Everyone
I have new to me '97 Aero that is having these issues:
1. Cranks for a long time (5-6 seconds) when starting whether car is warm or cold. Runs normally after it starts. (Have another 97 Aero that starts instantly, so know how it should be)
2. Stumbles sometimes when lifting off the throttle after a strong acceleration run. Almost like fuel cut off.
3. Sometimes hesitates when getting into the boost.. sometime feels like just a flat spot, other times more pronounced hesitation. Mostly before it is fully warmed up.
I was having a problem with what seemed to be a fuel cut off under certain circumstances when getting into higher end of boost range. Swapping the Bosch Blow off Valve for a Forge piston type seemed to solve that.
The car has JZW stage 3-4 tune on the ECU. It has a secondary boost gauge that indicates it is achieving 23-25 psi. Has a 3" exhaust, larger intercooler and the big green injectors.
I've already tried swapping the DIC and Boost Control Valve with known good ones from another '97 I have that is running well (the other car also has a 3" exhaust and a JZW stage 1 tune). I've also tried new NGK plugs to no avail.
I've not tried swapping the ECU with either a stock one I have, or the one from the Stage 1 tuned car. I don't know if that would be ok, since the other car does not have the larger injectors. I've read here that the fuel pump check valve can be an issue.
Is there anything else I should try? I was going to try replacing the fuel pump and check valves, but the check valves looks that they will be a pain and I might need Indy help so wanted to eliminate other possibilities first.
When comparing this car to my other Aero, this car has noticeably more power at the top end (i.e. scary fast), but my other car does not have these glitches in the power delivery and my goal is to get this one running as well as the other one.
Any suggestions appreciated!
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