Car stuck in decel at times
#1
Registered User
Thread Starter
Car stuck in decel at times
Recent motor replacement
AEM EMS, RC injectors
Air pump removed
Symptoms:
In order to ge tthe car to stay running, I have to manually keep the rpm's at 2k for 1-2 minutes, then around 1500 for another 2 minutes or so. If I'm lucky, I can gently relieve all pressure from the gas pedal and she'll stay running around 800-1000 rpm.
The bogging under decel is usually when I back out of her around 6-8k and try to reapply as I near the apex of a turn(I was on the track this weekend). Not having the car accelerate when expected is not much fun nor safe on the track. This problem seems to lessen when the car is hotter(peak water temp was 102*C- nothing to worry about).
Additionally, I have the crud on my bumper that I had when I was shooting fireballs(sc'd w/ testpipe). Not sure if that's just normal for two days at the track or not. Because the decel sticking problem seems to lessen as the motor gets warmer, anyone think it might be a vacuum hose? The startup problem does not exist upon the first startup of the day, but almost everytime after that.
Thanks for any and all insight. I'll try to get some datalogging in the next day or two.
AEM EMS, RC injectors
Air pump removed
Symptoms:
In order to ge tthe car to stay running, I have to manually keep the rpm's at 2k for 1-2 minutes, then around 1500 for another 2 minutes or so. If I'm lucky, I can gently relieve all pressure from the gas pedal and she'll stay running around 800-1000 rpm.
The bogging under decel is usually when I back out of her around 6-8k and try to reapply as I near the apex of a turn(I was on the track this weekend). Not having the car accelerate when expected is not much fun nor safe on the track. This problem seems to lessen when the car is hotter(peak water temp was 102*C- nothing to worry about).
Additionally, I have the crud on my bumper that I had when I was shooting fireballs(sc'd w/ testpipe). Not sure if that's just normal for two days at the track or not. Because the decel sticking problem seems to lessen as the motor gets warmer, anyone think it might be a vacuum hose? The startup problem does not exist upon the first startup of the day, but almost everytime after that.
Thanks for any and all insight. I'll try to get some datalogging in the next day or two.
#2
I'd Stick the factory ECU back in and see if it runs right. If it does then it's a tune or AEM problem. If it doesn't, use the data stream to trouble-shoot it THEN hook the AEM back up. Maybe you can't do this with the RC injectors.
I'd stick the factory injectors back in at the same time I tried the factory ECU. Get yourself a decent baseline to work forward from. If that works well then you know it's the AEM or injectors.
I'd stick the factory injectors back in at the same time I tried the factory ECU. Get yourself a decent baseline to work forward from. If that works well then you know it's the AEM or injectors.
#3
Skip, I forgot to mention you were throwing some serious fire my way on the "fun" part of our drive last week. I didn't speak to you for quite a few miles and forgot all about it after my car developed its own problems. Don't know if that information helps but it should confirm your "crud".
#5
I work with what I've been told. It's pointing to running real rich with the fireball's and all.
It's not clear if this is new or has been this way since he finished his mods. If it's new then it's more likely something's broken.
It's not clear if this is new or has been this way since he finished his mods. If it's new then it's more likely something's broken.
#6
Registered User
Thread Starter
[QUOTE=e3opian,Oct 17 2006, 09:08 PM] Skip, I forgot to mention you were throwing some serious fire my way on the "fun" part of our drive last week.
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#8
Registered User
Thread Starter
Originally Posted by FF2Skip,Oct 17 2006, 08:04 PM
Symptoms:
In order to ge tthe car to stay running, I have to manually keep the rpm's at 2k for 1-2 minutes, then around 1500 for another 2 minutes or so. If I'm lucky, I can gently relieve all pressure from the gas pedal and she'll stay running around 800-1000 rpm.
In order to ge tthe car to stay running, I have to manually keep the rpm's at 2k for 1-2 minutes, then around 1500 for another 2 minutes or so. If I'm lucky, I can gently relieve all pressure from the gas pedal and she'll stay running around 800-1000 rpm.
I did notice that w/ the car off that the fuel pressure on the gauge at the fuel rail now reads 20-25psi with the car off whereas it used to read 30psi. With the motor running fuel pressure is now only 45 whereas it was 50psi before. This may explain the hesitation/missing at partial throttle and low rpm's that is present for the first time today.
Ek9, the motor is 2.5 weeks old, so yes, I'd say these are new problems, but the bogging under decel was present from the day I got the car back from the shop.
#9
Car off fuel pressure depends on whether you have a leak or not. Ideally the fuel pressure will stay near running pressure for at least an hour after you turn the car off. If you notice it bleeding down, something is leaking, an injector, check valve in the fuel pump or the FPR. This is not really a big issue though unless it's the injector leaking in which case you may be flooded when you try to start it. Car off fuel pressure is not really worth noting unless the car doesn't like to start.
You always measure fuel pressure with the vacuum line disconnected and plugged. 47-54 is stock I believe. With the vacuum connected, at idle, it'll read 8 psi lower.
You always measure fuel pressure with the vacuum line disconnected and plugged. 47-54 is stock I believe. With the vacuum connected, at idle, it'll read 8 psi lower.
#10
Registered User
Thread Starter
Two nuts on the exhaust header were missing and realized this yesterday while at work(I stopped by the auto hobby shop on the base). We added two nuts and off I went.
When I left work last night, the car started and held idle beautifully, but once on the highway, the car was spitting and missing.
When I left work last night, the car started and held idle beautifully, but once on the highway, the car was spitting and missing.