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ambmech1 · 03-08-2005, 07:44 PM

I picked up a 91 Buick Park Ave with 88,000 miles on it. Car has sat for 14 months. Needed all the brake lines replaced which I did Registered it yesterday, drove it home from work, about 10 miles, ran great. Was home for about 20 minutes, went to the store, no problems still ran fine. On the way back from the store pulling up to a light it stumbled twice but recovered When I stopped at the light it quit and wouldn't restart. It sounded like it was out of gas but gauge read 1/4 tank and the needle was still floating The engine tries to start but it seems to quit as soon as I let off on the starter. I hear the fuel pump working and I am getting pressure in the fuel rail. I have spark, checked all the fuses....ok I am baffled. No codes in the computer. Crank sensor? cam sensor? ECM? I did put $10.00 worth of gas in it, no difference Any ideas? Please help ty

george kujanski · 03-09-2005, 02:12 PM

sounds like your problem description is similar to mine:

http://forums.performanceyears.com/g...1/m/6991039111

keep in touch!

George

bjsgoat · 03-09-2005, 08:26 PM

What type of trans is in your car? Does the problem happen when coming to a stop or will it not even start now? There is a TCS solenoid in some of the electronic trannies that causes a similar prob.

ambmech1 · 03-10-2005, 05:47 PM

Im pretty sure its not the trans, had a grand am that had that problem, torque convertor stays locked in and when you stop feel like you forgot to push the clutch in car bucks and stalls.
I have another idea and let me know if this sounds right or if i'm way off base. Since the fuel pump activates for about 3 seconds when you first turn the key on to pressurise the fuel rails and the car will start for about 2 seconds and then immediately dies. Could it be something to do with what controls the fuel pump once the computer recieves a tach reference signal? Crank sensor? cam sensor? ignition module? I would bypass the fuel pump relay if i knew which one it was. Being a park ave there are about 10 relays under the hood.

7t4mula · 03-13-2005, 07:51 PM

You know... That last post by Ambmech1 reminded me of a similar problem I once had with a 2.8L Pontiac. The oil press sending unit was giving the computer a bad signal, wich in turn shut down the fuel pump. It was GM's answer to having people continue driving if they lost oil pressure. Unfortunately if it is getting a bad signal, it shuts down the pump and you have no idea why... My car had very similar stumbling, stalling, and failing to start symtoms. Good luck!

Bill Eveland · 03-14-2005, 12:07 PM

The pump could be bleeding down, have you actually checked to see what the pressure was at the rail, should be at 35psi.
Iv'e replace the pcm on these sililar cars, try to give the pcm a rattle with your hand to see if that does anything.

ambmech1 · 03-14-2005, 05:54 PM

thanks guys I will try that, I do have the ecm hanging down from the dash. I just wish I could figure out where the fuel pump relay was. Guess I'm gonna have to find a book for that vehicle. there are 2 relays under the ecm but not sure what they are for, and about 8 of them under the hood. if anybody can think of anything else i really do need this car, the weather is not quite ready to put the tempest back on the road.......ty

george kujanski · 03-14-2005, 09:52 PM

According to the book, in the right side of the dash is the relay center. there are two vertical columns of relays, the left column has three relays, the right column hs 4. The fuel pump relay is the second one down on the right (could be labelled "H") column. pin 4 of the relay is what feeds the fuel pump; jump that term to the battery and the pump should run. It should be a gray wire from that terminal to the harness.

If you have fuel pressure, a sensor problem should show up as a code tho. I get no codes on mine but it's looking like the problem is the pump and the computer has no sensors for that.

I would think a bad crank sensor would set a code.

george

ambmech1 · 03-15-2005, 06:55 AM

Thanks George appreciate the info you the man!

george kujanski · 03-17-2005, 10:49 PM

Update:
Ambmech: in my case, the in-tank pump was bad.

george

ambmech1 · 03-18-2005, 08:19 AM

Glad you found your problem...........still working on mine, haven't had much time the last few days but I have today off and the weather isn't too bad today, I'll let you know how i make out. Thanks again for the relay/wiring info.

ambmech1 · 04-09-2005, 02:02 PM

well........i went out today to see if i could figure out what was going on with this thing. tried to start it and guess what it fired right up. does this sound like a bad crank sensor or at least an intermittant one. im glad its running but cant trust it yet

george kujanski · 04-09-2005, 03:08 PM

I would think a bad crank sensor would set a code.

George

meanolegoat · 04-10-2005, 07:05 PM

We replaced many a crank sensor in those days; with no code stored. Try this--with engine at hot idle take a long 3/8 extension and place it on the crank sensor mntg pedestal. Tap it lightly with a screw-driver handle or small hammer. Very much akin to tap-testing an ecm/pcm/vcm. You can also take it off for visual inspection. Many times we'd see one that was chewed on by the balancer.
"mean"

ambmech1 · 04-12-2005, 05:24 PM

thanks mean, well the car did it again. drove about 30 miles, highway and city and when i went to pull in the driveway it stalled and would not restart i am just gonna go get a crank sensor and try it. i will let ya know

ambmech1 · 05-06-2005, 01:25 PM

Ok I changed the crank sensor, made sure it was lined up and it still wouldn't start, tries but just won't catch. That was last weekend. Went out today turned the key and it started again, been running now for a half an hour. Hooked up my OTC monitor and now I have a code, #41 cam sensor. I replaced that sensor but the code keeps coming back. It looks like there is supposed to be a magnet attached to the cam gear. I can't see it, but it is in a rotten spot to view it. If that magnet is damaged or missing will that cause an intermittant no start? How hard is it to replace? Remove front cover? Once engine does start it runs perfectly. Check engine light is burned out thats why I didn't think there was a sensor problem. Again any help would be appreciated Thanks.

2x4 · 07-20-2005, 06:42 PM

Heres a link to a "easy" way to replace the cam sensor magnets-
http://bellsouthpwp.net/p/a/padgett46/cammag.htm

Its pretty common with this era of 3.8's. Usually happends when you get "frisky" with the rpm's

I'd also highly reccommend swapping to the newer style ignition coils. I did on mine & got a couple extra MPG out of it, worth every penny!
http://bellsouthpwp.net/p/a/padgett46/coils.htm

TIAUTOMAN · 07-22-2005, 12:07 PM

THE DIAG FOR THAT CODE IS HORRIBLE
I WORK AT A GM DEALER, DO YOU SELF A FAVOR
REMOVE THE CAM SENSOR AND CHECK THE MAGNET ON THE TIMING GEAR SEE IF IT FELL OFF, MAY HAVE
BUT THIS WILL NOT KEEP THE CAR FROM STARTING
ONLY SYNCS THE INJECTORS TO START.
MOST OF THE TIME WITH THIS CODE AND HORRIBLE FLOWCHART THAT GM HAS, REPLACE THE CRANKSENSOR,PCM, CAM SENSOR TO COVER ALL BASES
BEFORE YOU DO MAKE SURE FUEL PRESSURE IS CORRECT , ALSO CHECK INJECTOR PULSE, AND SPARK
IF YOU DONT HAVE PULSE OR SPARK COULD BE A CRANK SENSOR OR WIRING PROBLEM

TIAUTOMAN · 07-22-2005, 12:08 PM

SSORRY DIDNT SEE THE POST ABOUT CHECKING THE MAGNET. SORRY BOUT THAT
IT WILL NOT CAUSE A NO START CONDITION, JUST AN EXTENDED CRANK

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