Problem that I can not figure out!
Thread Starter
Staging Lane
Joined: Dec 2007
Posts: 76
Likes: 0
From: west palm beach, fl
Ok well I got as far as getting the fittings for a gauge. I went to a coulpe local auto parts stores and none of them had gauges. So I went to a local speedshop and got a gauge and all the fittings. Now all I need to do is get the schrader valve out so I can hook up the gauge, but i cant fit my hands back there much less some small needle nose pliers. Why does everything have to be such a P.I.T.A!? 
12 Second Club
Joined: Jun 2005
Posts: 509
Likes: 0
From: Warner Robins Ga
The Matco fuel pressure guage I use doesn't say anything about removing the schrader valve to test fuel pressure. Actually all the FP guauges I've used never said to remove schrader valve.
Thread Starter
Staging Lane
Joined: Dec 2007
Posts: 76
Likes: 0
From: west palm beach, fl
Ok, well I got a pressure gauge hooked up and at idle its at about 35psi. When I take off the vaccum line on the regulator it goes up to about 45psi.
But even with the pressure up in the 40's its still hesitating and back firing.
It should be in the 40's normally right?
And now I think I have a new symptom. My fans dont seem like they are coming on. It never overheats, but it will get really hot if it idles for a super long time and I never hear the fans come on.
Anyway, I'm back to thinking its the coolant temp sensor.
BUT, someone correct me if i'm wrong, the sensor on the WP is the one for the computer and when I had my laptop hooked up to my car it was showing the correct temp. Does that mean its working fine?
I hope someone has the answer to my questions. You guys have been a lot of help so far, and talked me out of setting it on fire. haha. Thank you guys!!!
But even with the pressure up in the 40's its still hesitating and back firing.
It should be in the 40's normally right?
And now I think I have a new symptom. My fans dont seem like they are coming on. It never overheats, but it will get really hot if it idles for a super long time and I never hear the fans come on.
Anyway, I'm back to thinking its the coolant temp sensor.
BUT, someone correct me if i'm wrong, the sensor on the WP is the one for the computer and when I had my laptop hooked up to my car it was showing the correct temp. Does that mean its working fine?
I hope someone has the answer to my questions. You guys have been a lot of help so far, and talked me out of setting it on fire. haha. Thank you guys!!!
Last edited by 95phoenix; Dec 6, 2008 at 07:46 AM.
12 Second Club
Joined: Jun 2005
Posts: 509
Likes: 0
From: Warner Robins Ga
Try swapping the fan relay out with another. Seems to me your coolant temp sens is working fine. Fuel pressure looks good but you need replicate(sp) problem then check pressure. I loop the guage up on windshield and use wipers to hold it down then I drive the vehicle around till it acts up. I also hook scanner up as well and then I wait for it to act up then i check all my readings.
Thread Starter
Staging Lane
Joined: Dec 2007
Posts: 76
Likes: 0
From: west palm beach, fl
Try swapping the fan relay out with another. Seems to me your coolant temp sens is working fine. Fuel pressure looks good but you need replicate(sp) problem then check pressure. I loop the guage up on windshield and use wipers to hold it down then I drive the vehicle around till it acts up. I also hook scanner up as well and then I wait for it to act up then i check all my readings.
AND I have already been driving it with my laptop hooked up. Everything checks out fine. It doesnt just act up randomly either. Onced it switches to closed loop its a constant thing as long as the rpm's are low. Above 2k-2.5k rpms it drives perfect.
Thread Starter
Staging Lane
Joined: Dec 2007
Posts: 76
Likes: 0
From: west palm beach, fl
Ok. Well the fans come on, but its damn near close to overheating before the do. So I'm not worried about that right now since it never gets that hot while driving.
Anyway, thats how I feel about it too. I love my car but everytime I drive it I hate it more and more.
I REALLY need to figure this out though.
Anyway, thats how I feel about it too. I love my car but everytime I drive it I hate it more and more.
I REALLY need to figure this out though.
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Try a maf sensor from another car.
Get the car scanned and see what the o2 sensors are doing, that could be the problem. Did you use real extensions or make some with the kit the headers come with?
Get the car scanned and see what the o2 sensors are doing, that could be the problem. Did you use real extensions or make some with the kit the headers come with?
Thread Starter
Staging Lane
Joined: Dec 2007
Posts: 76
Likes: 0
From: west palm beach, fl
I had a scan tool at a shop hooked up to my car, then my laptop a few days later. In both cases the o2 were doing perfect so I have pretty much ruled them out completely. And I have the real extensions for them.
faulty or dirty injector?? If its not the ignition, not the fuel pressure, seems that its got good compression, no exhaust leaks, o2s seem fine.
I would try injectors or MAF. I know you cleaned it but it could be bad.
I would try injectors or MAF. I know you cleaned it but it could be bad.
Thread Starter
Staging Lane
Joined: Dec 2007
Posts: 76
Likes: 0
From: west palm beach, fl
Thread Starter
Staging Lane
Joined: Dec 2007
Posts: 76
Likes: 0
From: west palm beach, fl
Man, still having issues with this car... :/ well good news..black car is started... :p PS leak from hell and no idea where its coming from yet..looks like somewhere on the back of the rack or the pump 
stinks..was fine before and overheats alittle still but i should be able to fix that easily..sucks the stock temp gauge is a POS ><
My suggestion stands. LS1. if not..we can try the MAF on the white car if you want..i'm sick as hell right now but come Wednesday I should be alright
stinks..was fine before and overheats alittle still but i should be able to fix that easily..sucks the stock temp gauge is a POS >< My suggestion stands. LS1. if not..we can try the MAF on the white car if you want..i'm sick as hell right now but come Wednesday I should be alright
Teching In
Joined: Sep 2008
Posts: 26
Likes: 0
From: Dfw Texas
I feel your pain man, i have a 96 m6 z that's been doing the same thing for about 3 months, drove amazing when i first got it then at 95k miles the trouble started. At first i had some really clogged up cats, did away with those and it helped. Then i got the backfire and falling on its face under 3k. Honestly i hope you figure it out because i have seriously replaced EVERYTHING i literally have a new motor and accessories under the hood and brand new vacuum lines everywhere and it STILL MISSES. Im literally about to burn the car to the ground.
Thread Starter
Staging Lane
Joined: Dec 2007
Posts: 76
Likes: 0
From: west palm beach, fl
Man, still having issues with this car... :/ well good news..black car is started... :p PS leak from hell and no idea where its coming from yet..looks like somewhere on the back of the rack or the pump stinks..was fine before and overheats alittle still but i should be able to fix that easily..sucks the stock temp gauge is a POS ><
My suggestion stands. LS1. if not..we can try the MAF on the white car if you want..i'm sick as hell right now but come Wednesday I should be alright
stinks..was fine before and overheats alittle still but i should be able to fix that easily..sucks the stock temp gauge is a POS >< My suggestion stands. LS1. if not..we can try the MAF on the white car if you want..i'm sick as hell right now but come Wednesday I should be alright
Thread Starter
Staging Lane
Joined: Dec 2007
Posts: 76
Likes: 0
From: west palm beach, fl
I feel your pain man, i have a 96 m6 z that's been doing the same thing for about 3 months, drove amazing when i first got it then at 95k miles the trouble started. At first i had some really clogged up cats, did away with those and it helped. Then i got the backfire and falling on its face under 3k. Honestly i hope you figure it out because i have seriously replaced EVERYTHING i literally have a new motor and accessories under the hood and brand new vacuum lines everywhere and it STILL MISSES. Im literally about to burn the car to the ground.
Thread Starter
Staging Lane
Joined: Dec 2007
Posts: 76
Likes: 0
From: west palm beach, fl
As far as the tune, idk. I could try it but I dont want to keep wasting money. If I can kind of narrow it down to a computer problem then I will have to try it. But at this point I feel like I'm throwing money away to keep putting brand new parts on a broken car. I would be all for it if it would fix it but I'm tired of just throwing parts at it.