1991 Pontiac Sunbird 91 Sunbird runs on starting fluid but

1991 PONTIAC SUNBIRD
168,000 MILES • 6 CYL • FWD • AUTOMATIC
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JQ
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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.
Oct 20, 2008 at 10:16 PM
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RASMATAZ
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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?


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

Oct 21, 2008 at 5:53 AM
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JQ
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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
Oct 21, 2008 at 9:02 PM
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RASMATAZ
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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.
Oct 22, 2008 at 2:35 PM
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JQ
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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.
Oct 23, 2008 at 10:35 AM
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RASMATAZ
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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
Oct 23, 2008 at 11:27 AM
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JQ
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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.
Oct 24, 2008 at 12:57 AM
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RASMATAZ
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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


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


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

Oct 24, 2008 at 1:36 AM
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JQ
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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.
Oct 26, 2008 at 1:39 AM
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RASMATAZ
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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
Oct 26, 2008 at 2:00 PM
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RASMATAZ
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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
Oct 26, 2008 at 2:06 PM
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JQ
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I think I got the names of the sensors mixed around. I've already replaced the sensor that's inserted into the motor a couple inches. This sensor is very near the knock sensor on the back side of the motor. The vehicle will run like a champ as long as I inject starting fluid into the intake, as soon as I stop spraying it dies.

Josh
Oct 28, 2008 at 1:04 PM
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RASMATAZ
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Sounds more like a fuel problem-check the fuel pressure with a fuel pressure gauge with and w/o the regulator-if okay, Look for injection pulses-meaning injector/s are opening and closing providing fuel.

BTW Do you hear the fuel pump come On for 2 secs?
Oct 28, 2008 at 2:36 PM