[Goin' Topless]

Hi all,

My daughter's '88 Sunbird GT Turbo not starting. Apparently she decelerated while driving on the interstate and when she got back in the throttle, the engine didn't respond and she was losing speed. She pulled over and shut the car off (she wasn't sure if it was running or not), then tried to restart it.

It wouldn't fire.

I got it home and looked it over. The engine turns over quickly, battery has plenty of juice. Fuel pump runs when the key is on until the pressure builds then shuts off. No evidence of burnt wires or unconnected plug-ins.

Here is what is known:
Fuel pump is running with the key in RUN position, shutting off when the pressure builds.
The fuel filter was changed less than 6 months ago.
Battery less than a year old.
The coil is less than a year old.
Tuned up in the spring, Cap/rotor/plugs/wires.
Starter replaced this winter.
Ran like a swiss watch up until this happened.

I know it's not much to work on, but if anyone has any suggestions let's hear 'em.

Thanks in advance!

[bastard]

The symptom "engine turns over quickly" suggests a timing belt/chain issue. Often you can look into the oil fill to verify that things are moving. No movement means it snapped.

[mechanickeith]

Yep!!!! Sounds like a broken timing belt!!!

[uforacing]

Same thing that happened with my 88 turbo. The good thing is that nothing was hurt. (non interference engine)Replace belt and it should be good as new. They are kind of a pain to replace but not bad.

[Sirrotica]

Timing belt I also believe, no compression = spins over freely, like no plugs in the motor.

[Goin' Topless]

I checked the cam lobe positions, bumped the ignition a couple times, and the cam is moving, so the timing belt is good.

Didn't mean to mislead when I said it is spinning over quickly, just meaning that the battery isn't worn out.

[Sirrotica]

Check for spark next and if you have spark, you need to check the fuel system for fuel delivery. It has to be one or the other if the cam is turning and there is compression.

[mike nixon]

verify spark, verify injector pulse and fuel pressure, verify cam timing. They do skip time occaisionally.

Mike

[cuz68]

I would ck the gas cap also make sure it is on and tight.

[68birdragtop]

Check the fusible link running off the battery positive cable. If that is bad you will have no power to the injector. Ask me how many beers and smokes I had to figure that one out

Note:this was on my 1990 sunbird's 2.0 motor

[Goin' Topless]

OK, I'm back on the Sunbird again.

I'm checking things and so far things are leading me towards a weak fuel pump. Two things tell me this: It takes about 5-6 seconds for the line pressure to build up when the key is in the RUN position, which to me seems very long. I opened the schrader valve on the fuel rail and only got a small drop of fuel come out. Is that normal or indicative of low fuel pressure? Yes, I know a fuel guage would be best...

This car does have 118,000 miles and it's about time to change out the fuel pump anyhow.

I will check the fuseable link. Good suggestion!

[Sirrotica]

I'd say youv'e found the problem the system operates at 30 PSI + and you should see more than a drop from the schrader valve. I'm not sure on your car since I don't have one in front of me to look at but there is a valve that regulates pressure on most FI cars. I would make sure it isn't leaking off before pulling the tank to replace the fuel pump. Might save you alot of work before ripping into the fuel tank to replace the pump if it's just the regulator. It still may be the pump but easier to check that first.

[TIAUTOMAN]

If you think its the fuel pump, put a shot of carb spray down the throttle body and see if it starts...............if it does, then you know its a fuel issue at least

[Goin' Topless]

I'll verify by shooting some stuff in the throttle body.

The fuel pressure regulator was no good when I bought the car and I replaced it. THAT was a pain. Not as bad as replacing the starter on a turbo Sunbird, but it's up there...

[Tin Injun Tom]

Topless, 118K miles dosn't nessicarily mean the fuel pump is due. They would be more of an age issue than a usage IMO. That being said, the car is twenty years old.

I believe if the fuel level isn't constantly run below 1/4-1/8 tank, the pump could last indefinately, though. Before you pull it, see if you can tell if the tank has been down previously.

[Goin' Topless]

Update: I had two problems, the fuel pump was weak (verified with a pressure guage) AND the ignition module was toast, which was the real problem in the first place. I replaced the pump and sending unit (lines were rotten) anyhow.

I replaced the ignition module, BUT now the turbo doesn't produce any boost. Was the wrong module sold to me?

[Ron Landis]

Originally Posted by Goin' Topless

Update: I had two problems, the fuel pump was weak (verified with a pressure guage) AND the ignition module was toast, which was the real problem in the first place. I replaced the pump and sending unit (lines were rotten) anyhow.

I replaced the ignition module, BUT now the turbo doesn't produce any boost. Was the wrong module sold to me?

vacuum line to wastegate? Just a possibility. Happened on my Mclaren GP. Good luck. Ron

[Goin' Topless]

I'll check that, but the turbo was working fine before the ignition module took a crap??? Is there a difference in control modules between a turbo and a normal engine?

[Goin' Topless]

OK, so that I understand how turbos work, when the vacuum is high the wastegate "diaphagm" receives a vacuum signal and keeps the gate open, allowing the air to exhaust? When throttle goes up and vacuum goes down the gate closes to produce boost?

If that were the case then my wastegate is stuck open, not putting any boost to the motor?

[mechanickeith]

Did you put in a module that was programed for a turbo car??