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No Spark 3800 apv helpppppppppppp!


mrtooter
04-25-2006, 08:52 AM
Van just quit on highway - is this any indiction on were to look?

new crank sensor put in,about 4 used ignition modules, back probed all the wires in ignition circuit to the computer for continuity, all is well, checked all the fuses including 20amp in engine compartment, fuel pressure if good, injecters are comeing on when cranking, checked all grounds and cleaned them, did a diagnostic test from shopkey5 still no spark,

any ideals on were else to look my wife is driving me nuts this is her van to get all the grandkids and drive me nuts even more. a lose , lose situition lol:evillol:

think hard what havnt i checked? thanks in advance

richtazz
04-25-2006, 09:36 AM
check the harmonic balancer to see if it separated and re-check the crank sensor for a signal. Just because you recently replaced it doesn't mean it isn't bad.

mrtooter
04-25-2006, 09:35 PM
balancer looks ok , any ideal how to check the cranks sensor while its hooked up?

richtazz
04-26-2006, 10:31 AM
unplug the connector, hook up your ohm meter to the crank sensor, and have someone crank the engine. The ohm meter will detect a change in resistance in the sensor as the shutter on the balancer passes through it if it's working. Also double check the wiring harnesses at the ICM. They are fairly common to get corroded, or it's easy to bend them while intalling a new module.

mrtooter
04-26-2006, 12:13 PM
were exactly should i put the ohm meter and should it be set on ohms or volts/ thanks for your help ,

richtazz
04-26-2006, 02:25 PM
set it to ohms. There are 4 spades in the sensor itself, and each adjacent pair controls 3 cylinders. The crank sensor is a dual hall effect switch which sends a signal to the ECM each time one of the reluctor blades on the harmonic balancer passes through it. You must insure that the harmonic balancer doesn't touch the crank sensor. If your van is 93 or older, the crank sensor is adjustable, and the air gap needs to be set when installing the sensor. If it's misaligned, it can allow the balancer to hit the sensor, causing it to fail and the van to stall. To test, put the red probe of your multimeter on the outside terminal, and the black on the terminal next to it, and crank the engine. the reading should change as the harmonic balancer reluctor passes through the sensor. Test the other half in the same manner. If you get no difference in reading, then the sensor is bad.

mrtooter
04-26-2006, 06:09 PM
my van is a 93 with a new gm rebuild 3800 engine , the crank sensor does not appear to be adjustable as it sits on a pin in the middle and has a bolt on each side. im willing to buy a new icm but i have tried 3 or 4 used ones from the junk yard with no luck, we have spent 3 full days doing tests on it, its not worth spending alot of money on so any help u can give im very thankful for.

SAGE12
04-27-2006, 11:19 AM
my van is a 93 with a new gm rebuild 3800 engine , the crank sensor does not appear to be adjustable as it sits on a pin in the middle and has a bolt on each side. im willing to buy a new icm but i have tried 3 or 4 used ones from the junk yard with no luck, we have spent 3 full days doing tests on it, its not worth spending alot of money on so any help u can give im very thankful for.

IT NOT THE ICM
I'M HAVEN SAME PROB ON MY CENTURY
I HAVE NEW CRANK SENSOR NEW ICM & NEW CEM NO CHANGE

SAGE12
04-27-2006, 11:20 AM
my van is a 93 with a new gm rebuild 3800 engine , the crank sensor does not appear to be adjustable as it sits on a pin in the middle and has a bolt on each side. im willing to buy a new icm but i have tried 3 or 4 used ones from the junk yard with no luck, we have spent 3 full days doing tests on it, its not worth spending alot of money on so any help u can give im very thankful for.

IT NOT THE ICM
I'M HAVEN SAME PROB ON MY CENTURY
I HAVE NEW CRANK SENSOR NEW ICM & NEW CEM NO CHANGE

jeffcoslacker
04-27-2006, 03:14 PM
"The power of Christ compells you..."

http://www.tldm.org/News4/ExorcistPriest.jpg

mrtooter
04-27-2006, 04:39 PM
every car is different ,i over look nothing im beyond the basics, time to get down and dirty, i need some high tech help!:banghead:

jeffcoslacker
04-27-2006, 04:46 PM
Run an alternate 12v supply to the ICM and see what happens....

mrtooter
04-27-2006, 08:05 PM
i dont recall 12v going to the icm only 5.5volts from the computer,, i ran a bunch of tests provided by shopkey5 who gets them from general motors

i have entire wiring diagram and all general testing methods,

jeffcoslacker
04-27-2006, 09:43 PM
i dont recall 12v going to the icm only 5.5volts from the computer,, i ran a bunch of tests provided by shopkey5 who gets them from general motors

i have entire wiring diagram and all general testing methods,

Yeah, I think you're right.

Check continuity of the coilpacks yet?

mrtooter
04-28-2006, 06:43 PM
i have replaced entire assebbly icm and coil packs as a unit, mind you they were all used from the scrap yard, and one that was known working

jeffcoslacker
04-28-2006, 06:59 PM
i have replaced entire assebbly icm and coil packs as a unit, mind you they were all used from the scrap yard, and one that was known working

Never assume "known good", especially where already running yourself in circles. If your pin outs check good with regard to the ICM, then obviously there's a problem there.

I wish I had a buck for everybody that ever told me "It can't be _____, because I just replaced it"

Even when _____was a new part, it's usually the problem....

maxwedge
04-28-2006, 07:28 PM
Has anybody put a scanner on these vehicles and looked for cranking rpms, or checked the harness from the ckps to the icm, no cranking rpm indicates no ckps signal to the icm or pcm. I did not read all the posts as there are some add ons from the original.

maxwedge
04-28-2006, 07:30 PM
Never assume "known good", especially where already running yourself in circles. If your pin outs check good with regard to the ICM, then obviously there's a problem there.

I wish I had a buck for everybody that ever told me "It can't be _____, because I just replaced it"

Even when _____was a new part, it's usually the problem....
Amen, same as I did "everything" and it still isn't fixed!

richtazz
04-29-2006, 01:44 PM
:werd: to both MAx and Jeff

mrtooter
04-30-2006, 10:07 AM
so if i hook it up to a scanner again and check to see if it has cranking rpms that means the cranks sensor is working ok correct? i did check all the wires from icm to the computer a they all are fine. Grounds are all ok and fuses are all ok, it is a new crank sensor, and checked the balancer for and damage, did find one loose wire at the crack sensor but never made any difference when i replaced plug end.

drift101
03-29-2008, 04:03 PM
did anyone ever figure out what was causeing this? Whats the fix

maxwedge
03-30-2008, 10:07 AM
2 year thread, no responses?

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