I just had my turbo 2 engine rebuilt around 1000 miles ago, and now it has developed an issue where it doesn't want to stay running. Most of the time it starts and immediately dies, just like if the VAF was unplugged. Occasionally it will start and stay running. When it stays running, it will idle smooth, but revving it will cause it to sputter and then die. When it sputters, the tach drops and the wideband goes lean, so it looks to me like it's losing both fuel and spark at the same time.

Here is my complete setup:
Streetported S4 turbo engine
BNR Stage 3 turbo
Emissions deleted except for BAC and thermowax
Rtek 1.8 ecu
720cc primaries and secondaries, recently cleaned and flow tested.
Walbro 255 pump rewired with a Bosch relay per the how-to on this site
Otherwise stock. A/C and power steering are still intact, alternator and battery are new.

Sometimes when you turn the key on, the solenoid on the underside of the UIM clicks nonstop and the TPS LED flickers at the same time. When the car is running and then dies, it is doing this clicking and won't restart until it stops. There is also a slight buzzing sound coming from the CAS when the key is first turned on. I can only hear it when I have my head in the engine bay and someone else turns the key on for me.

Any help is appreciated. I've been struggling with this car since the rebuild and I'm just ready to enjoy driving it.

 

Soooo stock ecu?

 

Check to see whether the solenoid clicking is the relief solenoid (2 wires are Black/White wire and a Blue/Yellow wire) or the switching solenoid which also has a B/W wire in addition to a Blue/Red wire. Both are contolled by the TPS. With key to on the B/W wire at each of these two solenoids should read 12 volts, the Blue/Yellow wire reads below 2 volts if the engine has been warmed some, but if cold, then it reads a bit higher, and the Blue/Red wire would read 12 volts.

 

Sorry, Rtek 1.8 ecu.

The car started up fine today. Idled great and revved smooth. I drove it around the block and it started cutting out. I got almost into the driveway and it died and wouldn't restart. It acts like it wants to start, but just floods itself. Deflood and it floods again, even with the throttle pedal to the floor.

 

I got it to start and drive fairly well today. It ran great, except the factory boost gauge wasn't working and it wouldn't build any boost. I hooked up my boost leak tester and I couldn't see any leaks, but it sounds like there may be something letting air out on the bottom side of the UIM. I guess I'll take that back off and see what I can find.

 

I should also add that it idles very rich, around 11.5:1, with the resistor set to full lean.

 

I still can't find any vacuum leaks, and all sensors check out good. I was thinking today that I don't know how old my plug wires are. They're NGK wires, and for all I know they could still be the original ones. I'm buying new NGK wires, so I'll get them on as soon as they arrive. Could bad plug wires cause the issues I'm having?

Edit: I forgot to test my coolant temp sensor. I'll pull the alternator off and do that while I wait on plug wires to arrive.

 

Coolant temp sensor checked out fine. I realized I checked voltage output and fuel pump trigger at the VAF, but I never ohm tested it. FSM said it should sweep between 200-600ohms. Mine bounces all over the place while slowly moving the flap, and regularly goes above 600ohms.

Is anyone selling a S4 turbo airflow meter?