1994 suburban (no spark/no fuel)

flatrate572 · 09-30-2009, 06:00 PM

Hello All, glad i found this forum,im a 10 year KIA tech thats allways owned chevys lol....and my burban broke down on me 2 weeks ago.....i am not getting any spark or fuel.............i started off simple and used a inline spark tester coming off of the ignition coil. and found that i was only getting 3 or 4 sparks when first cranking engine,then nothing for rest of crank time,and one final spark when turning key to off position......so i figured the ignition modual was to blame.......went out back of the dealership and found me a good running cash for clunkers 93 1500

and took the whole distributor with all the extras attached and installed it in my suburban, same thing....a few sparks from the coil then nothing the rest of cranking time,and 1 final spark when turning key off..... ok so a new coil was cheap so i tossed one on, same thing...

.....hmmmmm.......so i went out to that same truck that ran great and took the pcm for testing purposes, installed the pcm from other truck into mine,NO CHANGE,next day i tried a different pcm from a different running truck,this time i swapped my prom from my original pcm to the new/used pcm,NO CHANGE............lol and thats when i kicked the clunker dodge parked out back.stupid dodge.....
so i break out my ol haynes manual to test some wires at the pcm,to see why i have no power to my fuel fuse,only to find out there are no pin numbers or connector references for the wires i want to test only colors. and it says in the haynes book im looking for a red or maybe pink wire

lol.

i know i know im writing a book here.
one more thing,im testing the wires using a power probe 3 tester,and i noticed that my pcm metal case has 8.4 volts when the key is on,and ground when off,since ive never known any pcm case to be powered,i dont think this is normal...

ok one more thing..........does anyone have a pin out of the pcm and connectors?

Thanks for reading my ramblings
thanks in advance
FLATRATE572

southern10 · 10-01-2009, 08:08 PM

just throwing a wild guess here but, have you check the crank sensor? also have you checked injector pulse with a test light or noid light? i don't remember if you said you did or not? ihave on quite a few occasions found the crank sensor will not allow for spark and injector pulse. i will see if i can pull up a schematic for you and post it if i can.

Kennyray · 10-01-2009, 08:24 PM

check the ignition module in the dizzy, a 94 does not have a crank sensor. A bad module will stop both spark and fuel.

flatrate572 · 10-02-2009, 06:30 AM

yea i replaced the icm along with the distributor.....stolen from a running truck.with no change. im thinking i have a ground wire shorted to power.......kinda weird that the pcm has voltage on the outside of the case,when key is in run position.

main problem im having is that i cannot find a pcm diagram that has the correct conectors that i have....my pcm has (2) 32 pin connectors,and all the diagrams i can find have (1) 24 pin and (1) 32 pin connectors at pcm.so its been real hard to find the correct wires to trace problem

another question i have .........where does the under hood fuel pump fuse get its power from???? ignition switch? pcm? inside fuse box? anyone know.........got no power at that fuse....actually i got a strong ground there

thanks

09-30-2009, 06:00 PM	#1
flatrate572 Junior Member Join Date: Sep 2009 Posts: 2	1994 suburban (no spark/no fuel) Hello All, glad i found this forum,im a 10 year KIA tech thats allways owned chevys lol....and my burban broke down on me 2 weeks ago.....i am not getting any spark or fuel.............i started off simple and used a inline spark tester coming off of the ignition coil. and found that i was only getting 3 or 4 sparks when first cranking engine,then nothing for rest of crank time,and one final spark when turning key to off position......so i figured the ignition modual was to blame.......went out back of the dealership and found me a good running cash for clunkers 93 1500 and took the whole distributor with all the extras attached and installed it in my suburban, same thing....a few sparks from the coil then nothing the rest of cranking time,and 1 final spark when turning key off..... ok so a new coil was cheap so i tossed one on, same thing........hmmmmm.......so i went out to that same truck that ran great and took the pcm for testing purposes, installed the pcm from other truck into mine,NO CHANGE,next day i tried a different pcm from a different running truck,this time i swapped my prom from my original pcm to the new/used pcm,NO CHANGE............lol and thats when i kicked the clunker dodge parked out back.stupid dodge..... so i break out my ol haynes manual to test some wires at the pcm,to see why i have no power to my fuel fuse,only to find out there are no pin numbers or connector references for the wires i want to test only colors. and it says in the haynes book im looking for a red or maybe pink wirelol. i know i know im writing a book here. one more thing,im testing the wires using a power probe 3 tester,and i noticed that my pcm metal case has 8.4 volts when the key is on,and ground when off,since ive never known any pcm case to be powered,i dont think this is normal... ok one more thing..........does anyone have a pin out of the pcm and connectors? Thanks for reading my ramblings thanks in advance FLATRATE572

10-01-2009, 08:24 PM	#3
Kennyray Senior Member Join Date: Oct 2005 Location: Birmingham, AL Posts: 895	check the ignition module in the dizzy, a 94 does not have a crank sensor. A bad module will stop both spark and fuel. __________________ None of the secrets of success will work unless you do.

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10-01-2009, 08:08 PM	#2
southern10 Junior Member Join Date: Jan 2009 Posts: 6	just throwing a wild guess here but, have you check the crank sensor? also have you checked injector pulse with a test light or noid light? i don't remember if you said you did or not? ihave on quite a few occasions found the crank sensor will not allow for spark and injector pulse. i will see if i can pull up a schematic for you and post it if i can.

10-02-2009, 06:30 AM	#4
flatrate572 Junior Member Join Date: Sep 2009 Posts: 2	yea i replaced the icm along with the distributor.....stolen from a running truck.with no change. im thinking i have a ground wire shorted to power.......kinda weird that the pcm has voltage on the outside of the case,when key is in run position. main problem im having is that i cannot find a pcm diagram that has the correct conectors that i have....my pcm has (2) 32 pin connectors,and all the diagrams i can find have (1) 24 pin and (1) 32 pin connectors at pcm.so its been real hard to find the correct wires to trace problem another question i have .........where does the under hood fuel pump fuse get its power from???? ignition switch? pcm? inside fuse box? anyone know.........got no power at that fuse....actually i got a strong ground there thanks