Mechanics

91 RUNS ON STARTING FLUID BUT

1991 Pontiac Sunbird

Engine Mechanical problem
1991 Pontiac Sunbird 6 cyl Front Wheel Drive Automatic 168000 miles

I have a 91 Pontiac Sunbird that is giving me much trouble. The car was driving fine and all of a sudden died on the hwy. When I tried to restart it, it would crank and kinda act like it wanted to start but would not. The car will run like a champ if I spray starting fluid in the intake, but will not run once I stop spraying.

I've changed the Ignition Module, Coil packs, plugs, wires, cam position sensor, knock sensor, fuel filter and it still acts the same way. When I check for fuel pressure at the fuel rail I show 40 psi. Using a noid light I know I have a signal at the injector. I have good spark all the way around. I've taken the fuel rail assembly apart and cleaned it entirely. Each injector was removed and new O rings where applied. I know that atleast 2 injectors were pumping fuel as I did not get them entirely back in place and they were spraying fuel.

Anybody who may be able to help I'd appreciate it. This has me frustrated to no end. Thanks in advance.
Avatar
JQ
October 20, 2008.




Hi JQ and welcome to 2carpros

The car will run like a champ if I spray starting fluid in the intake, but will not run once I stop spraying.

Do you hear the fuel pump come on for 2secs when key at run position? If not its a power problem -if so Its either it has an incorrect fuel pressure or the injectors are not schronizing.

What liter engine is this?


http://www.2carpros.com/forum/automotive_pictures/12900_fuel_pump_20.jpg


Tiny
Rasmataz
Oct 21, 2008.
The car has the 3.1L V6 and yes the you can hear the fuel pump kick on for about 2 seconds each time you turn the key on.

However, I have no idea if the injectors are schronizing?

Thanks

Tiny
JQ
Oct 21, 2008.
Sir-can you provide the fuel pressure readings. The injectors listen to it if its clicking, or use a noid lite to see if its getting power and get back to me.

Tiny
Rasmataz
Oct 22, 2008.
Alright, the fuel pressure at the schrader valve is consistently at 41psi. It seems to hold that preasure for a good amount of time following fuel pump prime. Also, I used a noid light to test the exposed injector. The light flickered as if the injector was to be properly working. I appreciate your help. Thank you.

Tiny
JQ
Oct 23, 2008.
Test the crankshaft sensor resistance should read 900-1200 ohms. Also set the meter to AC 2 volt scale crank engine over reading should be.05volts slow cranking to 1.0volts at greater cranking speed

Tiny
Rasmataz
Oct 23, 2008.
I was told by the parts store and by a pontiac service tech that this car did not have a crank sensor. It has a camshaft position sensor. Can you tell me where the crank sensor is located and what I should be looking for? I assume it should be on the lower front of the engine if it has one? I appreciate your assistance. Thank you.

Tiny
JQ
Oct 24, 2008.
Sir-some auto references says it has a CPS and the software that am using says it has one for a 3.1 engine.

Is this a direct ignition system-meaning don't have a distributor. and also is it VIN T engine?

Try looking on the right side of the block below the exhaust manifold-see below pic location E


http://www.2carpros.com/forum/automotive_pictures/12900_cps2_3.jpg




http://www.2carpros.com/forum/automotive_pictures/12900_cps3_2.jpg


Tiny
Rasmataz
Oct 24, 2008.
Thank you for your assistance. This motor has a direct ignition. The sensor you reference as " E" is located against the block below the manifold near the knock sensor. This according to my parts store is the camshaft position sensor, but this is not a crank sensor? I've already replace the camshaft position sensor located at " E". I appologize for any confusion.

Tiny
JQ
Oct 26, 2008.
The CPS protrudes thru side of engine block to within.05 of an internally mounted crankshaft reluctor ring-

CPS -Also look under the DIS module
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Tiny
Rasmataz
Oct 26, 2008.
Post subject: 1991 Pontiac Sunbird 91 Sunbird runs on starting fluid but

If there's a problem with the crankshaft position sensor I don't think it will start even if you use starting fluid

Tiny
Rasmataz
Oct 26, 2008.

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