Some one has to know this?

[boost_dependent]

Ok I have posted many times in the problem diagnosis section and no one really answers me. I have been tring to get my car running for a month and a half now. lets see here is the problem my car will not start and stay running and if I give it gas it dies! i changed pretty much everything from coil packs, cam angle sensor, wires, plugs, tested the ISC, I even had the ECU Rebuilt. and still it won't start. I thought it was the MAF sensor because I disconnected the eclectrical plug from it and started the car and the damn thing started right up and idled. I let it idle for about 2 or 3 min then pluged the connector back in and the car stumbled and died. so i figured it was the MAF. but I swapped in a working MAF and it still wouldn't start so I unplugged the MAF again and yep it starts and idles alright. the only thing is that if I try and give it gas it's kinda like it's a delayed reaction ... as in I tap the gas it revs up after I have let off the gas?? if I floor it it wants to die? I pluged the MAF back in and sure enough it died??? I am so confused... some one please help me ! I just did a complete engine rebuild and it wasn't doing this before the rebuild.

 

[kpt4321]

If unplugging the MAS makes the car run, that means your air metering is banjaxed. That means time to look for boost leaks.

 

[boost_dependent]

exactly how do I go about doing that? I have no emissions it's all caped off .. no vacuume lines they are all capped.

 

[boost_dependent]

so if I do have a boost leak and I have my MAF (electrical Plug) connected the the car wouldn't start? why is that? I mean that would have to be one hell of a leak wouldn't it? I did do a compression test and that was perfect but I don't guess that has anything to do with a boost leak? some one help me out here so I can understand all this!

 

[Big Woo]

You may also want to check the wiring for the MAS. I.E. follow the wiring from the MAS through the harness all the way to the ECU. Inspect for cut or frayed wires, also check all connections for broken of damaged pins.

Another way to check for inlet air leaks is to spray carb cleaner at all of the possible leak points. intake to head, t-body to intake, i/c piping, BOV flange on so on,wile at idle. When ideling the engine will be drawing a vacuum so if a leak is present the carb cleaner will be drawn into the engine, and will cause a rise in the running RPM for a moment or two. Don't forget under thw intake.

On some DSM's it is possible to plug the injector resistor pack (the white rectangle with an aluminum cover on the fire wall) into the ISC motor plug, and vice versa between the ISC motor and the injector resistor pack plug, there-by leading to the asumption that everything is pluged in correctly, check to make sure that they are pluged in correctly.

good Luck

 

[boost_dependent]

i did shoot all the wires on the harness side of the MAF according to the haynes manual and all the voltages were exactly right same with the ground. I will check all the other stuff you have mentiond and let you know. Thanx for the good reply.

 

[boost_dependent]

ok I just did the boost leak test and it sounds like it's comming out of the #2 injector? I can wiggle the injector and the air pitch changes but still pisses out. as soon as I take the air pressure off hose off of the tester it all pisses out in about 2 seconds i put 25 PSI in there. could this make the car not start?

 

[Tevenor]

Originally posted by boost_dependent
ok I just did the boost leak test and it sounds like it's comming out of the #2 injector? I can wiggle the injector and the air pitch changes but still pisses out. as soon as I take the air pressure off hose off of the tester it all pisses out in about 2 seconds i put 25 PSI in there. could this make the car not start?

Are you missing the injector-head seal?

 

[unior]

an injector hissing wouldn't be enough air to cause the car to not run. IMHO

how about fuel? fuel pump, filter?

does the car actually run for an indefinite amount of time with the MAF unplugged?

 

[boost_dependent]

yes it does... i probly let it run for a good 15 min last night??? I am really confused here???

 

[GSXanimal]

It has to be a bad connector or some part of the harness that runs to it.

 

[zac83]

put a scantool on it and deterimine which of your inputs are bad... Coolant temp (if it reads -40 for instance), karmen count (MAF reading), and also check your IAC%(should be 30-60%).

 

[gsxitement]

Originally posted by GSXanimal
It has to be a bad connector or some part of the harness that runs to it.

exactly...thats the first thing i thought of when i read the problem, i would deffinatly check the actual plug and where the wires are attached to the pins on the inside of the harness. i had a problem with the cam angle on my 2g and after everything it turned out to be the plug...but it had also burned out my cam angle in the process.......check that

 

[boost_dependent]

but if I shot the wires down with the multimeter on the harnes according to the chiltins manual all the voltages and grounds are good? on one of the ground wires on that harness the manual says it should have continuity..... ok well it doesn't say like 0.01 ohms+/-5 or anything just continuity. I had like 45 ohms?

 

[unior]

Originally posted by zac83
put a scantool on it and deterimine which of your inputs are bad... Coolant temp (if it reads -40 for instance), karmen count (MAF reading), and also check your IAC%(should be 30-60%).

i like that idea the best - that would make sure your getting proper signals from your maf

 

[gsxitement]

one of the best tests you can do on a sensor thats giving you problems is the wiggle test....simply while the car is trying to run either you or someone else tries wiggleing the sensor.....this coupled with a scan tool can yield great results....but if you don't have access to a scanner, you're just gonna have to rely on your ears, and listen for any drops, or cean spots when you're wiggling the connector around

 

[boost_dependent]

ok.. I am about to blow this car to peices!! I got a new MAF and it still has the same effect.... car will not start with the MAF pluged in... if I unplug the MAF the car starts and idles. I can't give gas fast or it will die as soon as I hit the pedal. i have checked and rechecked everything damn thing you can think of. I just got my ECU rebuilt could they have jacked my ECU up???? can you test the ecu some how?

 

[kpt4321]

Did you fix that goddamned boost leak yet?

You know that the car has a problem, I don't want to hear you bitching about it not starting until you solve the problem. Fix that boost leak, test it again, and then fix the rest of them.

The car is fine if it starts with no MAF. It just has an air metering problem, which could be caused by leaks. Fix them.

 

[boost_dependent]

yes I fixxed the boost leak. I put new injector seals in there tightned it down and did the boost leak down test again and no air pissing out! So now what? is wrong with this car?

 

[unior]

time to switch to a map sensor

 

[Big Woo]

Since you said that you receintly had the ECU rebuilt, perhaps you could try pluging in a differnt ecu. I you have access to another one it only takes a few minutes to try it. Then you will be happy if the cars works, or you can scratch another item off your list of things to try.

On a seperate note prehaps you should take a step back, sounds like you are getting frustrated. Sometimes the more you look at something the less you see. If you get my meaning.

 

[Green Manalishi]

I would gess that by unplugging the MAF, the ECU uses some base map setting for idle. So try removing the MAF completely and see if it runs like when it's unplugged, then plug it in while it's off & see what happens. If it dies whenever the MAF is plugged in, then it would suggest that the wiring is hosed. Check the pins on the plug, and look to see if you didn't cut any wires when you put the engine back in.

Other things to check would be the vac line routing, the ISC, and the throttle body ports.

...and how about that cel you must be getting by now?

 

[boost_dependent]

well i just put my ECU in someone elses ride and their car started right up. I am pissed now because I have no clue what is.... unless it is wiring. but My friend put his data logger on it and it didn't show anything wrong? Does anyone have a detailed schematic diagram of the wiring harness?

 

[kpt4321]

How can you check the MAF, if the car won't start with it plugged in? The datalogger isn't going to tell you too much.

It has to be something in the air metering system. That means that if the MAF is working, the air metering is off (something clogged, boost leak, etc) or if the MAF isn't working (wiring, etc) that is the problem.

 

[boost_dependent]

ok i got a hold of the complete wiring schematic for the harness. I have ohmed out each wire from the ECM harness to the MAF harness and all the wires have continuity. we did notice that the maf, TPS, and coolant temp all share the same ground. we changed out all those sensors and still have the same effect. everything is getting the correct voltage at all the sensors. none of them are shoted to ground. but it wil start (granted you have to crank on it for a while) up with the MAF unplugged and idle for as long as you want it to, but as soon as you plug the MAF in it dies. and I have done a boost leak test and all is good. compression is good. chyanged coil pack, plugs, wires, CAS, TPS, Coolant Temp, MAF.
checked all engine grounds. what else can I do? even if it sounds simple or easy or stupid tell me what I can check or try! anything to get the car running.

oh and I just noticed that my head lights don't work? all the other lights come on though... !

also let me say that tonight we have gotten it to start with the MAF plugged in but only for maybe 2-3 seconds then it just dies.