Starts up then dies...

[JTURBOGSX]

well heres the Deal I bought 1990 tsi fwd with 100k I knew it had a problem but I dont know wut it is. It starts up when when we spray start up gas into it it fires right up and runs for a few seconds then dies the ECU FUEL PUMP have just been replaced wut else could it be ?

 

[I-luv-em-all]

Make sure you are getting fuel. Make sure you are getting spark. Make sure the ECU, coolent temp sensor, and CAS are connected and working properly. Also check for Vacuum/Boost leaks.

 

[JTURBOGSX]

so where should i start i know theres a big boost leak when i have to spray start up flluid into the Throtle boddy ? but thats the only way it will start

 

[I-luv-em-all]

Well start with the easy stuff. It isnt hard to check for fuel and spark. Then do a boost leak test and see where that leak is coming from, and fix the leak and then see what happens.

 

[JTURBOGSX]

The car is bone stock could there be that big of boost leak also how do I do a boost leak test if it doesnt run ? also how do I check to see if its getting fuel and spark

 

[I-luv-em-all]

Here you go, you dont do this test with the car running. http://www.vfaq.com/mods/ICtester.html

Also how to check for fuel: Just take off any fuel line past the fuel filter, just to make sure the filter is not clogged, or just take off the fuel rail and see if you any gas comes out, i guess.

For spark: Just take off a spark plug wire and hold it to something metal and see if you get spark, or get a little shock, do that to all the wires. Take out the spark plugs too and see if they are fouled.

 

[steve]

If the car runs when you spray starting fluid into the intake, it would seem like you have compression and spark so start looking at the fuel system because that seems to be whats missing. Make sure the fule pump is running with the key in the start position. Take the return line off the regulator and run it into a bucket to make sure you have fuel reaching the injectors and then make sure they are working.

Steve

 

[JTURBOGSX]

where is the regulator located .... does it have a white cat on top ?

 

[I-luv-em-all]

You are not too familiar with these cars yet are you . Oh well, you will be soon enough. The FPR is gold, and it is at the end of the fuel rail with a fuel line goin to it, and it also has a vacuum line that goes to the fuel pressure solenoid, the same vac line that the boost gauge should be tapped.

 

[steve]

The FPR is gold, and it is at the end of the fuel rail with a fuel line goin to it, and it also has a vacuum line that goes to the fuel pressure solenoid

SO you don't get lost, the FPR is on the drivers side of the fuel rail. The smaller hose goes to the fuel pressure solenoid and the larger hose is the return line.

Steve

 

[I-luv-em-all]

I know, maybe i just didn't explain it as good as I thought. Thanks for the clearing it up.

 

[JTURBOGSX]

So if there is no fuel comming out of the line when I start it up means the pumps not working correct ? and if there is no fuel comming out wut should I do First

 

[I-luv-em-all]

Honestly, the first thing you should do is pick up a Haynes or Chilton manual. That will give you some trouble shooting advice, for the problem you are having. And also it will tell you how to check to see if the fuel pump is working correctly, along with all of the other starting components, and almost everything else on these cars a person would need to know.

 

[herm1357]

i would honestly try another ecu, i have just been through this problem a week ago, i went through 4 different ecu untill i got one that actually worked.trust me!

 

[JTURBOGSX]

Problem is Ecu's aremt Cheap so.............

 

[steve]

It's not unusual for this to be due to capacitor leakage in the ECU.
You can try grounding the pin the ECU uses to keep the fuel pump running after the power from the starter circuit turns off. That's pin 7 on the MPI relay or pin 56 on the ECU. If the car keeps running you should pull and check the ECU.

Steve