emory

Hi,
I am a new guy to the forum.
I have this problem with my 1993 Surburan. I am getting Gas to the TB and I am getting spark. If I spray Carb Cleaner into the throut of the TB it will crank. I have pulled the gas line loose from the TB and it is pumping fuel and I can hear the fuel pump whirl when I turn the key on. Both of the Ing. In the TB are pulsing. Reacon why it will not run? Could the Ing. be bad?
Why would both of them go bad at the same time? When I spray Carb. cleaner into it it will idle fine. But as soon as I quit it cut's off. any help would be Great!
Thank's

jkgray80

Can you hear/feel them pulsing or see them pulsing? You can use an adjustable timing light to see the spray patterns. Patterns should look like tee-pees. If they are dripping or spraying in none 'tee-pee' form they are probably restricted. If you have ran extremely low on fuel lately your pump could have picked up a bunch of trash & clogged the injectors.

emory

all I used to see if they were working was a test light. Ground to one side and stick the point of the test light in the other side and while my son-in-law turned the engine over the light would blink. On both Ing.
could you explain your method to me, please?
The fuse block on the dash close to the driver's knee does not have a fuse for the fuel as I can see. is there any more fuse's anywhere?

jkgray80

The test light told us that everything is doing its job to pulse the injectors, but they may not be firing. Check on the P-side under the hood at the 'fire wall'. There will be a black plastic cover w/3black plastic nuts holding it on. Behind the cover is the fuel pump relay. I can not remember if there are any addtional fuses though. W/an adjustable timing light, you can match theinjector pulse to the timing light pulse & make the pulse viewable.

emory

Thank's, I will check that in the morning. Pretty dark outside now. lol

emory

Relay is good, anybody got any Idea's? Have been reading other post as to where the Oil Pressure switch has something to do with whether the fuel pump would work or not. anybody know how to test that?

shawnvw

Oil pressure switch will power the relay after there is enough pressure at the switch. But the ecm also powers that relay. Its kind of a back-up. The ecm should turn on the relay before engine start. If you are gettin the pump to run, then the relay and fuses to the fuel pump are fine. There may be a problem with fuel pressure. While the pump is pumping, it may not be enought. Also check fuel level, could be out of gas? Maybe the fuel level sensor is bad and shows 1/4 tank when its accually out of gas?

It defenately sounds like a fuel problem if it runs when your spray the cleaner into it.

jcw1500wt

I had the same problem about a year ago. Changed Plugs & wires, nothing, Replaced injectors, nothing, Replaced fuel filter, nothing, Finally I changed the ignition module, It fired up. A$35.00 part for 2 weeks of cussin'& fussin'. LOL.

ehhget

Where is the ignition module located? Is it a relay in the fuse box?

ehhget

Emory,
My neighbor had the same problem right down to spraying starter fluid into the TB on his BMW and it turned out to be his fuel pump. Like shawn said it has to be fuel related if it runs when you spray it.