1988 S4 problem starting (devek 6 litre stroker car)
09-24-2015, 12:17 PM
#151
Pro
09-29-2015, 01:04 PM
#152
Rennlist Member
Thread Starter
we were still getting spark, so maybe it shorted out the LH as John said! i don't know, but the owner is SO happy that he is driving his car after 8 months of trying to figure this thing out!!!!
thanks JOHN!!!!!
thanks JOHN!!!!!
09-29-2015, 01:46 PM
#153
Rennlist Member
Yes, you will get spark, the EZK sends an rpm signal to LH pin 1. Also connected to the same point are the tach and the kick down relay.
But if there is a standard "53" relay fitted in place of the KD relay then it neatly shorts out the pin 1 signal and so the LH never wakes up.
Of course there should never be a relay in the KD position on a 5 speed.
Glad that at least the car starts again :-)
But if there is a standard "53" relay fitted in place of the KD relay then it neatly shorts out the pin 1 signal and so the LH never wakes up.
Of course there should never be a relay in the KD position on a 5 speed.
Glad that at least the car starts again :-)
09-29-2015, 04:53 PM
#154
Rennlist Member
Thread Starter
Yes, you will get spark, the EZK sends an rpm signal to LH pin 1. Also connected to the same point are the tach and the kick down relay.
But if there is a standard "53" relay fitted in place of the KD relay then it neatly shorts out the pin 1 signal and so the LH never wakes up.
Of course there should never be a relay in the KD position on a 5 speed.
Glad that at least the car starts again :-)
But if there is a standard "53" relay fitted in place of the KD relay then it neatly shorts out the pin 1 signal and so the LH never wakes up.
Of course there should never be a relay in the KD position on a 5 speed.
Glad that at least the car starts again :-)
01-11-2016, 08:28 PM
#155
Rennlist Member
Thread Starter
ok, here is the update:
the car runs, as it did before the owner started mucking around in the fuse panel and putting in relays where there shouldnt be any. BUT, it still smells like gas in the cabin. i backed out the fuel to about 44psi vs 48psi as im at around 40psi and have a very rich hp dyno run, and with 45more HP, he should be fine near my fuel pressure with 30p injectors and a stock S4 comupter.
But, it still has a hard time starting sometimes. like its flooded. it didnnt do it when he came over for help, but it did it earlier in the day a couple of times. thats why i thought there was a leaky injector. however, while he was over, the fuel pressure remains at max levels for 5 10 mins and then drops to 0 after about 30min.. (to spec) so if it was the injector, its intermittant or something else.
Ive had the car when this happens. you go in to the store, and when you come out and start the car, it wont start.... you have to floor it... it starts and pukes out black smoke and then its perfectly fine.
???????
thoughts?
oh and yes, we had him change out the leaking fuel dampers.. no change, but now the fuel dampers dont have fuel drops coming out of them.....
the car runs, as it did before the owner started mucking around in the fuse panel and putting in relays where there shouldnt be any. BUT, it still smells like gas in the cabin. i backed out the fuel to about 44psi vs 48psi as im at around 40psi and have a very rich hp dyno run, and with 45more HP, he should be fine near my fuel pressure with 30p injectors and a stock S4 comupter.
But, it still has a hard time starting sometimes. like its flooded. it didnnt do it when he came over for help, but it did it earlier in the day a couple of times. thats why i thought there was a leaky injector. however, while he was over, the fuel pressure remains at max levels for 5 10 mins and then drops to 0 after about 30min.. (to spec) so if it was the injector, its intermittant or something else.
Ive had the car when this happens. you go in to the store, and when you come out and start the car, it wont start.... you have to floor it... it starts and pukes out black smoke and then its perfectly fine.
???????
thoughts?
oh and yes, we had him change out the leaking fuel dampers.. no change, but now the fuel dampers dont have fuel drops coming out of them.....
01-12-2016, 01:25 AM
#156
Rennlist Member
ok, here is the update:
the car runs, as it did before the owner started mucking around in the fuse panel and putting in relays where there shouldnt be any. BUT, it still smells like gas in the cabin. i backed out the fuel to about 44psi vs 48psi as im at around 40psi and have a very rich hp dyno run, and with 45more HP, he should be fine near my fuel pressure with 30p injectors and a stock S4 comupter.
But, it still has a hard time starting sometimes. like its flooded. it didnnt do it when he came over for help, but it did it earlier in the day a couple of times. thats why i thought there was a leaky injector. however, while he was over, the fuel pressure remains at max levels for 5 10 mins and then drops to 0 after about 30min.. (to spec) so if it was the injector, its intermittant or something else.
Ive had the car when this happens. you go in to the store, and when you come out and start the car, it wont start.... you have to floor it... it starts and pukes out black smoke and then its perfectly fine.
???????
thoughts?
oh and yes, we had him change out the leaking fuel dampers.. no change, but now the fuel dampers dont have fuel drops coming out of them.....
the car runs, as it did before the owner started mucking around in the fuse panel and putting in relays where there shouldnt be any. BUT, it still smells like gas in the cabin. i backed out the fuel to about 44psi vs 48psi as im at around 40psi and have a very rich hp dyno run, and with 45more HP, he should be fine near my fuel pressure with 30p injectors and a stock S4 comupter.
But, it still has a hard time starting sometimes. like its flooded. it didnnt do it when he came over for help, but it did it earlier in the day a couple of times. thats why i thought there was a leaky injector. however, while he was over, the fuel pressure remains at max levels for 5 10 mins and then drops to 0 after about 30min.. (to spec) so if it was the injector, its intermittant or something else.
Ive had the car when this happens. you go in to the store, and when you come out and start the car, it wont start.... you have to floor it... it starts and pukes out black smoke and then its perfectly fine.
???????
thoughts?
oh and yes, we had him change out the leaking fuel dampers.. no change, but now the fuel dampers dont have fuel drops coming out of them.....
What's happening is that the fuel pressure holds relatively constant until the dampers have emptied into the intake via the leaky injector(s), then the pressure drops pretty quickly.
It sounds like you reduced the fuel pressure to try to eliminate the gas smell in the cabin. The more important questions are (1) are you sure there is no fuel leak?? And (2) how are the AFRs running? Have you had a wideband O2 sensor on it, or are you tuning by the smell?
01-12-2016, 02:33 PM
#157
Rennlist Member
Thread Starter
Fuel-pressure spec: for 87+ cars, fuel pressure (with pump bridged) is 3.8 bar (55 psi), and after sitting for 20 min is 3.0 bar (44 psi) minimum. It sounds like it is well below that, even relative to your low starting pressure.
What's happening is that the fuel pressure holds relatively constant until the dampers have emptied into the intake via the leaky injector(s), then the pressure drops pretty quickly.
It sounds like you reduced the fuel pressure to try to eliminate the gas smell in the cabin. The more important questions are (1) are you sure there is no fuel leak?? And (2) how are the AFRs running? Have you had a wideband O2 sensor on it, or are you tuning by the smell?
What's happening is that the fuel pressure holds relatively constant until the dampers have emptied into the intake via the leaky injector(s), then the pressure drops pretty quickly.
It sounds like you reduced the fuel pressure to try to eliminate the gas smell in the cabin. The more important questions are (1) are you sure there is no fuel leak?? And (2) how are the AFRs running? Have you had a wideband O2 sensor on it, or are you tuning by the smell?
the fuel pressure change was only to get it into the more reasonable range for engine with only 330rwhp and 6 liter running 30lb injectors. we did tune it originally (well he did) and it was very rich. i didnt want to change things too much, so just dropped the pressure 4psi to 44 from 48psi.
but, i remember, when i had my pressure in the 48 psi range, the o2 sensor couldnt even fight it , so it was full rich, even idling. when i eventually dropped the pressure to the 40psi range, it started to hunt and the closed loop system was working. WOT was not much of an issue, but freeway MPG was not as good as it should have been. now, with pressure down, its close to a good tune. we wide band checked it too. 30psi injectors are just a little much for the stock ecu settings, even with pulling back fuel. but, if i had the CF intake, it might be near perfect as Anderson saw on his.
yes,, that is my guess, that there is a leaky injector. have you seen that before or heard of it? is what we are seeing the result of that? seems plausable.
as far as the pressure drop... i remember the holbert car would loose fuel pressure almost immediately. it was the check valve in the fuel pump from what was told to me. mixtures were good and there was never a starting issue. as far as the RRFR, it has one that he has had since the day it was built. it had a bad pining problem, and a couple of shops just kept richening the mixture up to fix it and nothing seemed to work. doesnt seem to do it as much now with the leaner settings and the cams set properly I dont think the engine is overly high compression, as that checked out to be about 195psi per hole. he has tried the high octane gas ,and it didnt help. seems to only ping on hot days, medium RPM and throttle ranges. siince the MAF was way out of spec and we got that rebuilt, that might have been the issue. hard to say. i dont think its pinging now, and that might have been the problem all along. again, this motor has about 100k miles on the stroker.
we need to hit the dyno to see where it really is both in power and mixture.