car wont start after rebuild

[36mafia]

ok heres the story of my car...i got a 1991 eclipse fturbo from an owner who had blown out the head gasket on his engine. he replaced the engine with the jdm(cyclone intake) engine, and redid alot of the wiring for the motor. he later blew that motor sending the psitong through the block. after getting the car, i rebuilt the motor with the blown head gasket. i had the block, and head machined. i used the common wiseco/eagle piston combo, crower valves and springs, and just about everything on the motor has been replaced. i dropped the motor in, and hooked all the wiring up, and completely went throught every aspect of the motor, before i tried to start it. the car rolled over and barely sounded like it was going to start. i had my friend who is a master mechanic come over and he was confused as to why it wont start. i spent alot of time trying to start it also. we worked on the timing for about 4 hours, and finding that the motor is timed, and still wont start. every little thing we thought about was either right, or it was replaced if broken. ive been working on this car for 1 year now, and working on starting it up for about 5 months on and off. im stumped as to why it wont start and maybe somebody knows why, because ive read so many threads and articles, and not one has helped. ive heared that it might be the power transistor...but im not sure. if anyone might know thanks alot.

 

[cheap90gsx]

possibly ecu? check spark, fuel, coil, and transistor.

 

[Colt4G63 also]

You would really have to be willing to share more information with us than that. All you really need is spark, fuel, and compression, but you haven't mentioned anything about the status of any of those things.

Put your master mechanic on here, and we'll have it running in a few minutes.

 

[36mafia]

oh yeah sorry. yes the car has fuel, spark and compression. me and my friend believe its the power transistor thats probably wasted, but were not sure. i would tell what the compression was, but it was back in july and i forgot. we did get the car running a couple times, but it ran like crap for the whole minute it ran, and when the rpms got below 1000, the engine would die.

 

[Lonnie gandee]

oh yeah sorry. yes the car has fuel, spark and compression. me and my friend believe its the power transistor thats probably wasted, but were not sure. i would tell what the compression was, but it was back in july and i forgot. we did get the car running a couple times, but it ran like crap for the whole minute it ran, and when the rpms got below 1000, the engine would die.

You obviously dont know what your talking about...You cannot have spark, fuel, compression and not have a running car.... Not gonna happen... If the SPARK transistor is bad, than your getting no spark......

Do you have a fuel pressure gauge?

 

[36mafia]

thats what im saying, the car HAS spark, fuel and combustion. i checked a bunch of times. the car can spark with a fried transistor. there will be a series of weak sparks, and then one big spark.

 

[Lonnie gandee]

Do you have a fuel pressure gauge.....

 

[36mafia]

and no i dont have a fuel pressure guage. my friend has all those tools and ran the tests for me. i mean he knows what hes doing, he works for roush

 

[Lonnie gandee]

Well, after that professional diagnosis , your shit should fire right up, and be running like a champ......

Have fun

 

[36mafia]

haha. i really dont know that much about turbo cars. thats my problem. so you dont think its the transistor?

 

[dylnwit]

Have you checked the CAS to make sure it's lined up right, you can have it 180* off and it will still bolt right up. If that's right, then the transistor would probably be a logical next step. The only real non-fuel map difference between a turbo car and a non turbo car are a few extra lines here and there and obviously a turbo. Besides those, it's all covered by the ecu, and doesn't come majorly into play until your above idle anyways.

 

[4wdtalon]

does the car try to start .when you say you checked the timing are the dowls in the right position is cas. good .

 

[36mafia]

yah, that was acctually what i thought it might be also. but i spent alot of time timing that part. i could check again. have you known anyone that had a bad transisitor, or bad CAS?

 

[36mafia]

well it just rolls, and rolls. the timing was good. i think it was negative 5 degrees.

 

[dylnwit]

Manual is out in the shop right now, I'll grab it in the morning and see if there's tests for CAS and the transistor. There should be 12 volts on one wire going to the CAS when the key is in the run position, and another one of them is ground, i remember that much. Before you flat out replace it, just pull it off and make sure it's lined up right, notch on the end of the blade/paddle looking part should line up with the punch on the non-rotating part of it while your engine is at TDC.

 

[4wdtalon]

its a 91 right does it have the connector right on the cas or is it at the end a cable

 

[4wdtalon]

when you say your getting fuel into the cylinder

 

[Lonnie gandee]

The car will run and start with the cas flipped 180*

Theres a test online for the transistor.... has to do with a AA battery and a litebulb..


If the car, turns, and turns, and turns and then gives you an "UMPH" like it wants to start..... Then doesnt...I bet its the transistor.

 

[36mafia]

yah. thats what i was trying to say. ### the coil is sending a spark, but its a really small spark, and out of nowhere, the car will have a big spark and jump and act like it will start, and then go back to the rolling. and the same thing happens when i adjust the CAS. do you know what i mean?

 

[Lonnie gandee]

yah. thats what i was trying to say. ### the coil is sending a spark, but its a really small spark, and out of nowhere, the car will have a big spark and jump and act like it will start, and then go back to the rolling. and the same thing happens when i adjust the CAS. do you know what i mean?

I know exactly what you mean.... Thats the transistor..... 99% sure of it...

 

[36mafia]

alright cool. thanks alot. do you know about the aem twin fire ignition?

 

[Lonnie gandee]

Nope.... On these cars , the spark control is one thing that can handle alot of horsepower..

Its not the ignition thats bad on your car... Is the spark transistor..The coils are most likely ok.

 

[36mafia]

yah thats what i was thinking. alright thanks alot.

 

[dylnwit]

This is what my manual says about testing the transistor on a '90, not sure if the same procedures will work with a '91 or not, i know some stuff changed electrical wise, just not exactly what, but it does sound like what Lonnie gandee was talking about. As said above, it probably is the transistor, and sorry, didn't know the car would run with the CAS in backwards.

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[soulweaver]

Just replace it and tell us what happens