Mechanics

CRANKS BUT WONT START UNLESS I SPRA

1988 Oldsmobile Cutlass

Engine Performance problem
1988 Oldsmobile Cutlass 6 cyl Front Wheel Drive

cranks but wont start unless I spray starting fluid in the air intake the car is a 2.8 liter multi port injection and im getting spark and good fuel psi but when I take off the connector at the injector im getting power to both terminals on the harness I read that only one side should get constant power and the other should pulse when the engine is cranking
Avatar
Joedirt74
August 23, 2009.




Hello, If I understand your posts, you would need to unplug all injectors, so there won't be any voltage on that ground. With your vehicle, if your mfi, all grounds are connected. What model cutlass, there are several?

Did you use a gage to check fuel pressure? If there is an oil pressure switch in the fuel pump circuit, you can have good fuel pressure even without an rpm signal.
AD

JDL
Aug 24, 2009.
Its a cutlass sumpreme also I did use a fuel psi gauge and I hooked it up to the fuel rail and im getting 43lbs also there is a oil pressure switch tied into the fuel pump circuit and it does leak oil

Tiny
Joedirt74
Aug 24, 2009.
Can you check for an injector pulse, engine cranking? You might be able to use an led testlite across the terminals at the plug, engine cranking. The lite should pulse or brighten and dim. If no pulse, I'd look for a tach signal at the purple wire with white tracer, at ignition module. That sends the rpm signal to the computer, no rpm signal, no injector pulse. Could be a possible faulty ignition module? Before you replace anything, there is another test you can do. Later.

JDL
Aug 24, 2009.
Getting nothing when cranking by the way I did pull the module out a couple of weeks ago and had auto zone test it and they said it was good could there test be wrong

Tiny
Joedirt74
Aug 25, 2009.
You need a noid lite the autostore sells them. There is one more test, I can think of, place noid lite on injector plug. Undo the wiring connector for purple wire with white tracer at the module. Turn key just to the on position, Use a testlite connected to battery voltage, tickle the terminal for the purple wire with white tracer, if the noid lite pulses, I'd have to look at the ignition module.

JDL
Aug 25, 2009.
Hooked up noid lite turned on key got nothing. Turn engine over noid light lite up very dimly but did not pulse tried to unplug connector from module and tickle terminal with purple and white wire with 12volts and noid light did not lite up or blink should I check for continuity of the purple and white wire from the module to the computer

Tiny
Joedirt74
Aug 26, 2009.
What was the actual voltage reading at the injector? You can check circuits for continuity.

JDL
Aug 26, 2009.
With the key on I have 11 volts on the green wire and 11 volts on the pink and black wire of the connector that plugs into the injector and when I checked for continuity from the purple and white wire on the connector that plugs into the module to the green wire on the injector connector it read nothing but the fuel relay makes a noise when ever I put voltage to the green or pink and black wire on the connector

Tiny
Joedirt74
Aug 26, 2009.
Right now, it sounds like a problem on the injector ground circuit or the computer. Possible problem on the circuit that carries the rpm signal to the computer. I'm out of ideas.

JDL
Aug 26, 2009.
What about the oil psi switch that is wired in to the fuel system could it be interupting the injector signal

Tiny
Joedirt74
Aug 27, 2009.

AD