Engine starts then stops immediately after new head and other parts...

[stanlis]

To start off w/ this is a list of the stuff i just have put on my 92 plymouth laser rst awd...Stage 1 SBR head, stage 1 comp cams, dejon intake and upic pipe, k&n, joe p mbc, vrs 3" turboback exhaust, used 14b turbo (cause my other one broke), new stock fuel pump and fuel filter, and aslo i took off my abs and cruise control..Alright w/ all that said, today i finally get it all put back together and go to crank it up and it will start for a sec and then shut right back off..i'm clueless to what is wrong..i've checked all the sensors and they're all hooked up and i'm pretty sure the timing is correct..do any of u guys have any suggestions of to what's wrong? Any help would be really appreciated..Thanks

 

[Kollide]

how long does it stay running?

 

[stanlis]

probably no more than 2 or 3 seconds..

 

[92awddsm]

Check the o-ring on the fuel pump. Its probably broken or not seated. Sounds like it might be running out of fuel after it begins to run. This is something Ive seen a few times on modded dsm(fuel pump replaced)

 

[stanlis]

I just went and check my o ring and that wansn't the problem..

 

[stanlis]

Another thing it's doing, idk if this has anything to do w/ it not staying on or not, but u can visiblely see a puff of air shoot out somewhere around the intake manifold..i mean it's even visible from the driver seat..

 

[steve]

probably no more than 2 or 3 seconds..

Sounds like the fuel pump runs with the starter engaged and the stops when the ECU is supposed to keep it running and the car dies.

That's usually from capacitor leakage damage but it could be the wiring to the MPI relay too.

Try checking pin 7 on the MPI relay. If it stays at 12v all the time then the ECU isn't pulling it low to power the pump. If the car continues to run with the pin grounded check the ECU for capacitor leakage and the harness between pin 7 on the MPI and pin 66 on the ECU.

Steve

 

[stanlis]

Sounds like the fuel pump runs with the starter engaged and the stops when the ECU is supposed to keep it running and the car dies.

That's usually from capacitor leakage damage but it could be the wiring to the MPI relay too.

Try checking pin 7 on the MPI relay. If it stays at 12v all the time then the ECU isn't pulling it low to power the pump. If the car continues to run with the pin grounded check the ECU for capacitor leakage and the harness between pin 7 on the MPI and pin 66 on the ECU.

Steve

well i tried that too and it still doesn't seem to be the problem .....i mean the car will stay runnin if i hold the throttle but it's really really rough and as soon as i let off it will cut off..any more suggestions??

 

[steve]

I mean the car will stay runnin if i hold the throttle but it's really really rough and as soon as I let off it will cut off.

That's very important information. Had you told us that I wouldn't have sent you off to check the fuel pump circuits.

Does it seem like it's not running on all the cylinders?
Have you pressure tested the intake to make sure you don't have any/boost/vacuum leaks?
Have you checked the ISC? Actually tested not just checked that it's plugged in.
Is the CEL on?

Steve

 

[oldman]

Also check and make sure that plug wires are in the right order, maf plugged in and no leaks between the maf and turbo.

 

[stanlis]

That's very important information. Had you told us that I wouldn't have sent you off to check the fuel pump circuits.

Does it seem like it's not running on all the cylinders?
Have you pressure tested the intake to make sure you don't have any/boost/vacuum leaks?
Have you checked the ISC? Actually tested not just checked that it's plugged in.
Is the CEL on?

Steve

Yeah..that's exactly how it's acting, like it's not running on all cylinder..i dont have the tools to do a boost/vacuum leak test or the isc test, but it's not throwing a CEL...i'm gonna check the ISC later..it's actually making a wierd noise tho..like when i turn the car on, it makes a constant clicking noise...

 

[stanlis]

Also check and make sure that plug wires are in the right order, maf plugged in and no leaks between the maf and turbo.

I also tried that and still nothing

 

[oldman]

I also tried that and still nothing

Have you done a compression test yet?

 

[stanlis]

I finally figured out what it was!..It was the 4 little bushing that go into the head, that the fuel injectors go into..i guess i got into too much of a hurry and didnt see that they were missing ..my car runs great now..Thanks guys and sorry for the aggrivation

 

[steve]

Yep, Missing injector insulators would tend to cause some huge vacuum/boost leaks.

Did you find them while pressure testing or just notice the mistake?

Steve

 

[stanlis]

I started trying to think of everything that i had changed and then i started looking at the differences in my heads and noticed that they didnt send insulators w/ my new head..i changed them and it started right up!

 

[steve]

Do yourself a favor to avoid problems down the road and pressure test the intake when you have a chance. If your lucky you won't have any leaks but most people aren't lucky.

Steve