2G Trouble starting, once car does start idles around 1500 then dies after few seconds

[A87talonAWD95]

Hello, first post on here been looking through a lot of other posts and I don’t see anyone has a similar issue if I missed it please push me in the right direction .

Back story: purchased 1995 Eagle talon tsi AWD 2 years ago with blow motor and had some trans issues. Been slowly working on getting it back on the road. ( last time it was plated was in 2013) I have driven the car a few times around the block but would drive terribly. Most recent fix was replacing the coolant temp sensor wiring harness. Previously I would have to turn the key back and forth multiple times before the starter would turn and crank the engine over. After replacing the connector the car started on the first turn of the key and ran extremely well other than running very rich. It popped a CEL once actually running correctly for the 02 sensor on the 02 housing. I had an extra and replaced it. Once I did that the car went back to having issues starting and once I do get it to start ( after cranking for 2 min) it idles at 1500-2000 rpms then dies even if applying throttle it dies.

Engine/ trans Mods :
1.)Cheap eBay 16g ( plan to replace this with something better once it is running correctly)
2.)450cc injectors ( stock)
3.)255lph fuel pump
4.)new timing belt , head gasket , all gaskets really
5.)Kiggly flex plate & ARP bolts
6.) mishimoto front mount
7.)Cheap EBay BOV ( plan to replace this with something better once it is running correctly)
8.)99 Black box Ecu and 99 TCU
9.)black top 1g Cas
10.) stock exhaust other than no name exhaust manifold


Sensors on throttle body have been replaced along with rebuilt throttle body. New coolant temp sensor wiring. Have fuel (clean injector spray ) have spark ( all spark plugs and wires spark) compression on motor is 145-147 on all 4 cylinders. Checked vacuum lines and all are connected or capped off still checking for boost leaks but no couplers were messed with after changing 02 sensor and installing wire for coolant temp sensor. Did also try and use the old 02 sensor again but no change. Maf connected or disconnected doesn’t make a difference either

Have ignition switch, starter relay, 190lph fuel pump on order. Video attached or car running fine before 02 sensor was swapped

 

[miliman13]

Maf connected or disconnected doesn’t make a difference either

Then I would test the MAF !

I recall a long putting the MAF in the freezer, then using a using a heat gun to warm it up to measure its resistance, i believe don’t quote me, it’s been a while.

 

[A87talonAWD95]

Then I would test the MAF !

I recall a long putting the MAF in the freezer, then using a using a heat gun to warm it up to measure its resistance, i believe don’t quote me, it’s been a while.

Thanks! I will give it a test tomorrow and see. Seems odd it would off stopped working so quickly but then again it is a DSM

 

[pauleyman]

Hello, first post on here been looking through a lot of other posts and I don’t see anyone has a similar issue if I missed it please push me in the right direction .

Back story: purchased 1995 Eagle talon tsi AWD 2 years ago with blow motor and had some trans issues. Been slowly working on getting it back on the road. ( last time it was plated was in 2013) I have driven the car a few times around the block but would drive terribly. Most recent fix was replacing the coolant temp sensor wiring harness. Previously I would have to turn the key back and forth multiple times before the starter would turn and crank the engine over. After replacing the connector the car started on the first turn of the key and ran extremely well other than running very rich. It popped a CEL once actually running correctly for the 02 sensor on the 02 housing. I had an extra and replaced it. Once I did that the car went back to having issues starting and once I do get it to start ( after cranking for 2 min) it idles at 1500-2000 rpms then dies even if applying throttle it dies.

Engine/ trans Mods :
1.)Cheap eBay 16g ( plan to replace this with something better once it is running correctly)
2.)450cc injectors ( stock)
3.)255lph fuel pump
4.)new timing belt , head gasket , all gaskets really
5.)Kiggly flex plate & ARP bolts
6.) mishimoto front mount
7.)Cheap EBay BOV ( plan to replace this with something better once it is running correctly)
8.)99 Black box Ecu and 99 TCU
9.)black top 1g Cas
10.) stock exhaust other than no name exhaust manifold


Sensors on throttle body have been replaced along with rebuilt throttle body. New coolant temp sensor wiring. Have fuel (clean injector spray ) have spark ( all spark plugs and wires spark) compression on motor is 145-147 on all 4 cylinders. Checked vacuum lines and all are connected or capped off still checking for boost leaks but no couplers were messed with after changing 02 sensor and installing wire for coolant temp sensor. Did also try and use the old 02 sensor again but no change. Maf connected or disconnected doesn’t make a difference either

Have ignition switch, starter relay, 190lph fuel pump on order. Video attached or car running fine before 02 sensor was swapped

Thanks! I will give it a test tomorrow and see. Seems odd it would off stopped working so quickly but then again it is a DSM

Invest in a cheap obd datalogger. Lots better than shooting in the dark. You can verify sensor inputs.
255 pump is likely providing too much fuel at idle.

 

[A87talonAWD95]

Invest in a cheap obd datalogger. Lots better than shooting in the dark. You can verify sensor inputs.
255 pump is likely providing too much fuel at idle.

Thanks! I will look into it. I have a 190 on the way to see if that helps also. It had previously started and ran decent until I changed the 02 sensor out. I tried the old 02 sensor and didn’t make a difference

 

[luv2rallye]

Then I would test the MAF !

I recall a long putting the MAF in the freezer, then using a using a heat gun to warm it up to measure its resistance, i believe don’t quote me, it’s been a while.

The MAF operates on frequency - not resistance.

Have you verified if the fuel rail pressure is correct and maintained for hours after engine turned off?

 

[pauleyman]

Thanks! I will look into it. I have a 190 on the way to see if that helps also. It had previously started and ran decent until I changed the 02 sensor out. I tried the old 02 sensor and didn’t make a difference

If memory serves that shouldn't have mattered. At cold startup you're in open loop. O2 sensor shouldn't matter.

 

[A87talonAWD95]

The MAF operates on frequency - not resistance.

Have you verified if the fuel rail pressure is correct and maintained for hours after engine turned off?

Fuel rail does have pressure. I pulled the rail out with injectors attached and turned over the engine and the injectors seem to fire as they should

 

[miliman13]

The MAF operates on frequency - not resistance.

Have you verified if the fuel rail pressure is correct and maintained for hours after engine turned off?

I assume the test measuring frequency is conducted with the MAF connected to harness or at the least connected to a voltage source to ; capture the square wave?

I ask because I have a spare MAF and I have a pocket oscilloscope . And In the last few yrs I’ve become more familiar with your discipline in Grad school and would like to conduct this test myself.

Thanks
also this could help OP.

 

[luv2rallye]

Yes MAF stays connected. Connect scope to ECU pin 90. Frequency should increase with increased air flow. MAF is a Karman-Vortex type. Do not spray any cleaner into the MAF - it will permanently ruin it.

 

[A87talonAWD95]

Yes MAF stays connected. Connect scope to ECU pin 90. Frequency should increase with increased air flow. MAF is a Karman-Vortex type. Do not spray any cleaner into the MAF - it will permanently ruin it.

Can this be tested with a volt meter? Is is the scope needed in this case to test. I was also digging around under the dash and saw the MPI relay is not bolted to the chassis would this make a difference? It has started and driven a few times

 

[A87talonAWD95]

Can this be tested with a volt meter? Is is the scope needed in this case to test. I was also digging around under the dash and saw the MPI relay is not bolted to the chassis would this make a difference? It has started and driven a few times

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[luv2rallye]

Can this be tested with a volt meter? Is is the scope needed in this case to test. I was also digging around under the dash and saw the MPI relay is not bolted to the chassis would this make a difference? It has started and driven a few times

Not unless your voltmeter can measure frequency (which most don't).
MPI relay not bolted down shouldn't make a difference.

 

[A87talonAWD95]

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[miliman13]

it idles at 1500-2000 rpms then dies even if applying throttle it dies.


Sensors on throttle body have been replaced along with rebuilt throttle body.

Do you have link ? If not a logger . so you can prove the TPS is working. I only mention it because I’ve experienced something similar.

Also doesn’t hurt to inspect the ECU to eliminate it , I have to found a few threads here were it was concluded it was the ECU even after passing visual inspection.

 

[A87talonAWD95]

Do you have link ? If not a logger . so you can prove the TPS is working. I only mention it because I’ve experienced something similar.

Also doesn’t hurt to inspect the ECU to eliminate it , I have to found a few threads here were it was concluded it was the ECU even after passing visual inspection.

I don’t have a logger currently. Don’t have a ton of funds to work with. I do have an extra ECU out of a 97 though that I put in it and it has the same issue I also swapped both the sensors on the throttle body and no change.

I am going to pull the fuel pump again tomorrow to verify nothing is clogged or came unplugged or connector isn’t burnt up or some sort.

 

[A87talonAWD95]

I don’t have a logger currently. Don’t have a ton of funds to work with. I do have an extra ECU out of a 97 though that I put in it and it has the same issue I also swapped both the sensors on the throttle body and no change.

I am going to pull the fuel pump again tomorrow to verify nothing is clogged or came unplugged or connector isn’t burnt up or some sort.

FIXED THE ISSUE!!!

Installed the 190 pump today and car started right up no issues and doesn’t stall out. The 255 I have with not even 2 miles on dies out after cranking for a while. Guess the 255 pump just had some kinda issue and didn’t make it long.

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[miliman13]

For some reason when I click on video it requires me to sign in to prove I’m not a bot …..

Thank you for updating the thread !

if you had link or a aftermarket pressure regulator with a gauge , I believe you would have caught this sooner.

Sounds like you got unlucky with a new defective pump.

 

[A87talonAWD95]

For some reason when I click on video it requires me to sign in to prove I’m not a bot …..

Thank you for updating the thread !

if you had link or a aftermarket pressure regulator with a gauge , I believe you would have caught this sooner.

Sounds like you got unlucky with a new defective pump.

Yeah probably would have, thanks for everyone’s help on this.