car running funny

[andrew4g63]

I have 91 TSI AWD A/T and I just finished with a motor install. It is all stock except for 14b and 450 injectors. At First it wouldnt start so i changed the plugs and it started right up no problems running great. I drive around about 5 miles and go home and shut it off to look for leaks ect... When I try and start it back up it would start for about 2-3 mins of cranking then it started. Now it misses and wont rev. It also starts up and goes to 3000 RPM and then drops to 750-850RPM after a little bit. It is missing but all the spark plugs are firing and the order is correct. Any suggestions would be awsome.

 

[talon1987]

i would check your fuel injectors see if there working .... and also when you put the 450cc injectors in did you change yur ecu to a 5speed ecu or did you have a eprom and just get it chiped ??


-Pat

 

[andrew4g63]

Well When i bought the car the guy who owned it had a M/T ecu in it. Didnt know till i checked. But I thought that it didnt matter if it was M/T or A/T ecu. And also all injectors are working. It has a bad misfire the spark of the #3 cylinder

 

[talon1987]

well the A/T ecu compenstates for 390cc injectors and the M/T compenstates for 450cc .... but for the misfire did you check yur wires could be a possible short in it i would ohm them out .... also check yur connectors makesure the coil pack and transistor are plug in all the way ive heard of cases where the connetors were just loose

-Pat

 

[andrew4g63]

ill check that stuff then get back to ya thanks

 

[andrew4g63]

wires are good and plugged in

 

[andrew4g63]

does anyone think that it could be the ecu or maybe CAS

 

[Talesin]

I'd triple-check that it isn't expecting 390cc injectors. Seriously.
2-3 MINUTES of cranking?! The starter isn't rated to be operated for more than 15-20 seconds at a time, with a 10-minute cooldown between.

Sounds like it's getting swamped, in regards to the starting. Pull a spark plug and look at the tip. If it's black or fouled, you're running stupid rich. If it's tan or medium gray, it's fine.
It *might* be the CAS, but do a plug read and explore other avenues before suspecting that. New Bosch replacements are around $600.

 

[andrew4g63]

It is def. running stupid rich or not firering at all, plugs are black with very little tan spec. I will go and find another ecu out of a M/T and see how it works. Would a bad CAS cause problems like these.

 

[andrew4g63]

So checked the ecu by putting an automatic one in car wont even start. I tried my ecu out of my 92 Laser M/T and it wouldnt start. Then I put the GVR4 ecu in and it didnt start all of these ecus are good becuase they worked in the laser. I put the original one back in and the car started again same problems. Revved to 3000 and then went down to normal 750-850 but still missed. Im thinking try new CAS. Any help would be great, because im lost on this one thanks

 

[chaclark83]

Check the coolant temp sensor they are notorious for failure on the 1gens. It is also notorious for connector failure. If the cts or circuit is bad it will take forever to start and foul plugs. Then when you put new plugs in it will start easy. then five minutes later the new plugs are shot and its a b**ch to start again.

 

[adidas_coin]

Incoming!!! POTENTIALLY stupid question...you're not running Champion plugs are you. guy I know ran them in a 2nd gen and they fouled in 7 min.

 

[andrew4g63]

Ive read about that before and thought it happened when the wires wernt plugged in. Could just the sensor go bad. I will switch it out when i get home tonight. Ill keep you guys updated Thanks

 

[andrew4g63]

No NGK BPR7ES gapped to .030"

 

[andrew4g63]

I changed the cts and made new connectors on the ends, Now it starts and only revs to 2000RPM and its runs normal till it idles down then the motor misses so bad it dies. im lost

 

[Nito15]

Check for boost leaks if you have checked for everything else (ignition system). When I did a 14b, 450cc injector swap on my cousin's AT 1g I had a couple of boost leaks throughout the ic piping before it ran like it should. Also i suggest making sure all the O rings from the injectors are properly seated on the manifold. As far as the factory Automatic ECu is concerned, I used the AT ecu and it worked fine with 450cc incetors but if you are uncertain if the ECU was working properly prior to the install I strongly suggest you have it tested on another DSM.
-hope this helps.

 

[chaclark83]

When you can start your car and watch the stock boost guage. If it shows boost when there isnt any or if it shows high boost when there is barely any then your ecu is bad. My old 92 acted like that, and I tried everything and it was the ecu all along. The ecu was reading boost when there wasnt any and was in turn adding fuel for it. then it would hit fuel cut without any boost.

 

[andrew4g63]

Decided to drive car today, It started right up and ran ok untill the idle lowered then it was missing hardcore. I drove for one block and the boost builds at all times, the stock gauge is never reading below 0 psi. The car bogs and will not rev high, also the ABS is coming on for no apartent reason when you are trying to stop.