Car starts and Idles fine , Hit gas immediately tries to die

[dacowgod]

Hey guys My brother picked up a 91 Eclipse GSX with a very blown engine.. I replaced the engine and we fired it up and the car will start and idle fine. When You hit the throttle the engine tries to die immediately ... Its not a boost leak and have tried 3 different MAS air flow sensors. ... not a plugged exhaust and no restrictions to airflow. Also replaced fuel filter...

If i kick the pedal in and out i can make it get to 3000 or so rpms.. and it will build boost weird and blow off wierd very ahrd to explain but say its at 3000 rpm and i floor it from there...the car will bog until its very close to stalling yet you can hear the turbo spool and when you let off the pedal it still blows off? ..

Oh I've checked and rechecked timing.. ..although I havent replaced the CAS yet i have checked its position and adjusted it with no effect.



The closest thing I have ever experienced to this problem puts you in mind of bad/unplugged mass air flow sensor.. or disconnected intercooler pipe... neither are the case... .the only thing left I can point at is the ECU ..but I have no other ECU to test .. Just hoping somebody else will have some insight..

 

[pitbull419]

How long did the car sit?Could it have bad gas?
Check your fuel pump?

 

[csgsx23]

Did you try and flip the little piece that sticks out of the CAS and goes into the cam over? If that is inverted the engine will not run properly.

 

[dacowgod]

nope.. i dont think it is bad gas..car was only down for about a month.. car doesnt run or smell like bad gas ... fuel pump is definitely doing its thing.. fuel pressure is normal... any other ideas?

 

[dacowgod]

yah i did flip the CAS 180 degrees... I found the position that idles the best but neither will let the car rev.. Good idea though i thought for sure that was the problem when i first started it ..

 

[pitbull419]

Whats your fuel pressure when the car acts like it wants to die
A bad fuel pump can still idle a car and run it if you pump the pedal

 

[dacowgod]

fp is 38-40 psi at all times.... but i never build an boost to get it any higher but it never drops lower....

 

[pitbull419]

Ok so when you hit the gas and it tries to stall, then you let off does it recover and idle?

 

[dacowgod]

exactly ......it doesnt matter how much i open the throttle it tries to stall unless the throttle is completely shut... That led me to TPS which I did unplug and try w/o it.. and it didnt make a big difference either... I know on my 95 I can unplug the tps and the car will run rich but will run ok. so i assume the 1g would be the same way...still stumped... :S

 

[1gDSM4g63]

Do a leak down test to make sure the engine is install properly. And how your afr readings? It could be you MAF need to be replace. Check the intercooler to throttle body pipe.

 

[dacowgod]

no logger..this is a 1g I am a 2g guy I have DSMLink and so forth for My ecu but all of that is moot point here... anyways Like i said I have 3 different 1G MAF sensors and all 3 respond exactly the same..I highly doubt it is the MAF Sensor.. I havent done a leakdown but i dont honestly see how that could help me in this instance either... I am trying to get an ECU to borrow to see if thats the problem

 

[zimfro]

Do you have black smoke coming out of the tailpipe? Does it smell like unburned fuel? It seems like you are running rich.

 

[dacowgod]

ya ... exactly what it seems like..... its really strange .. really wish i had a datalogger on this car but just not happening yet... No black smoke out of the pipe..though that doesnt mean its not rich.. either though.. I have an extra afc I might hook it up and pull some fuel and see what happens... I hate doing that w/o having any data ... what a pain

 

[dacowgod]

Found solution..thought i'd share... Pretty obvious one to... but oh well... I went to hook up the AFC so I could get a little bit of info from the car and also take away some fuel to see if it would help...low and behold... wires are already stripped for the afc on the harness... and the Airflow wire is cut in half.. .. the boyI bought it from must have had an AFC in it obviously so hooked the MAF wire back together and it revs now... now on to the next problem ... misfires dumb stuff.. I am sure its probably just fouled plugs though since i have been messing around with this other problem for so long... Thanks for all the input guys..

Ricky