hey guys i'm posting this for my friend , his car is a g35 greddy tt 600cc injectors , utec all the supporting mods .

anyways here's the story , a couple weeks ago when he drove his car around, when he came to a stop the rpm would drop very low and it dies a couple times .
so we thought it's the throttle body , changed that out for a brand new one .
car ran fine (very rough at idle a/f gauge was going from 14.0 to 16.0 ) we drove it around for 2 hours every seem to be fine.
on the drive home his car die on him again , this time it'll start back up and would die right away .
he have the nonfoulers on his downpipes which spaces the 02sensor pretty far way front the downpipe would this causes the car to run rough and stall out ?
or the engine got flooded and won't stay running ?
any advice would appriciated .

 

usually that "hot start" problem associated with large injectors also causes the rpms to dip really low when the car is idling after it's hot.

I have 440's and mine does that sometimes, the rpms drop really low when i push the clutch in to coast to a stop.

Did he have uprev reflash for larger injectors? also, try cleaning the maf sensor. At idle the car is closed loop so the stock ecu is controlling the a/f ratio (which comes from the readings it gets at the maf and at the o2 sensors)

 

My mods are plenum spacer and exhaust. My car idles very low but it bounces, from 300rpms to 900rpms (approx) and occasionally will stall out. I do not have injectors or utec or anything like that. Also it looks like my oil pressure is low. around 10psi at idle. Is my condition like his or does anyone have any suggestions or thoughts on what it might be?

 

Could you tell us more, if you guys...reset ecu after TB installed? Check any leaks?
Any codes?

 

Get to a qualified shop asap for a leakdown and compression test. I saw similar oil pressure in 2 of my motors just days before spinning main bearings due to oil starvation. Any smoke out the tailpipe? Have you checked your oil level?

 

He has a leak in the intake system behind the maf sensor most likely. That or he hit the map switch on the bottom of the UTEC by accident. Make sure the rotary dial window is turned to #1.

How have my two Michigan Greddy TT cars on stock motor been doing anyways? Haven't heard from you for a minute!

 

the oil in the car looks fine we checked everything .
we gonna check for leaks this weekend , i don't think resetting the ecu causes this to run poorly .
hi dave how have you been ? i'm glad you chimed in and give some advice , i think he has a leak somewhere as well , maybe his passenger kicked the utec and switch the map ? btw my car been running perfect , since i got rid of that p.o.s greddy eo1 , just got it retuned from Hal and its laid down a 425whp on a dynodynamics .
well last night the car finally started for a few seconds then he give it some gas it die again .

 

Been good. Having fun dealing with drama as always! Just doing some not so subtle advertising for my long term sucesses. How long has your and Neil's car been running flawlessly?

 

my has been running great since summer of 2007 , neil's car been running good until he swapped out injectors and retuned .

 

No smoke from tailpipe, I do use oil. I do not know if it is more than what other people have been. I hear this engine uses oil up a lot. at the time of this the oil is at proper levels.

When i accelerate or I guess i mean during normal driving, the oil gauge looks like the tachometer. The higher the engine revs the higher the oil pressure, to a max of about 70psi.

 

does anyone think that my two problems are related or causing one or the other? low idle/ stalling and low oil pressure.

 

How much oil do you have to add? I have only used a 1/4 quart in 2500 miles. Being FI at that.

Edit: No codes are being thrown?

 

probably 1/2 - 2/3 quart every 1000 miles. I did get a O2 sensor code but had them replaced. 2nd time in a year.

 

Well, low idle could be the cause of the low oil pressure. I sit at 30psi @900 rpms. If your idle is real low the car is barley running right. How low is it at and it idles ruff I bet.

Heck, it's hard to say I would first try a throttle relearn and go from there or turn on head lights and leave the battery unpluged for 30 min. You need to get that idle fixed first for sure. Hopefully your oil pump is ok.

 

Most of times, after replaced TB gives rough idle or etc. It's always good to reset ECU by pedal or disconnect battery.

 

I think I will clean the MAF, and throttle body this weekend, I have an appointment on Monday to get it checked out.

If anyone knows how to adjust the idle, that may help, or any other insight on this. I am not sure if it is adjustable.

 

just in case check ur fuel pressure at idle, my car was driving crazy for the same reason dying at idle and when i went to check my fuel pressure it was at 80!!!!!, so i changed the fuel pressure regulator, put it back at 45 and problem solved.......

 

we tried that , but the car wont stay at idle at all . it start then die instantly .

 

So the car won't even stay at idle?
Edit: my mistake. You posted on first thread about car won't even idle at all. This happend to me before after replace the TB....

 

the car would would stall out on it own sometime on the road , so we switched out throttle boddy ,i ran good for 2 hours and all problemscomes .