79403ta

will a map sensor cause a truck not to fire at all ?? i was working on the 1993 that i posted about before (1993 chevy truck 350 4l60e)...truck quit running at a stop sign just like you reached up and switched it off..no spitting or sputtering the truck was running good...now i have no spark but i do have injector pulse and spary out of the injectors when its spinning over..the truck had a code for a map sensor...i have no spark at the coil,distributor or anywhere else...i had an extra coil so i swapped it out and still no fire...when i replaced the distributor (bad bearing) about a week and a half ago it came with a new ignition module already installed...any help is greatly appreciated

777stickman

I don't have schematics for your '93, but could it be the ign sw?? Check for 12v power at the coil and/or ign module with the key in run & start.

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"R57 3CAR" 210 2dr post. 420HP 355 F/I 4sp 3:42 posi. (Dale Earnhardt tribute done by me.)
75 GMC Vandura 3/4 Ton
78 Chevy K5 Blazer
98 Chevy K2500 Suburban LT/7.4
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broughy84

Pull the dist cap, pull the ignition module out of it and take it to autozone, they can test it. My truck did the same thing, that's what it was. You will need a flat screwdriver and a 5.5mm socket and driver.

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Matthew Brough
1998 Chevrolet Venture -- 104,000 miles
1988 Chevrolet Silverado -- 156,000 miles
1996 Chevrolet Cheyenne -- 107,000 miles

79403ta

i've got 12v to the coil but not to the ignition module itself and from my schematic it is a black wire with a red stripe that runs straight from the computer to the ignition module itself...so i pulled the glove box and found the black/red wire and it had 9v with the key on and i had just charged the battery (checked battery to double check it had 12.8 volts)....could it be something burned up in the computer ?? thanks

CrazyHorst

All indications would typically point to an ignition module...BTW reinstall with fresh silicone dielectric grease otherwise another failure is soon to follow...the ign module uses the aluminum base as a heat-sink and the silicone grease is the "thermal bridge".

I don't think the ign is ECM-triggered in your model year...there is probably an ESC (knock sensing) modification for spark retard. The other thing to check is the reluctor-ring. I would also double-check all the weather packs to make sure a spade connector didn't get inadvertently pushed back into the plastic housing during the parts swaps.

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1988 Chevy R-30 1 ton DRW pickup (201k)
1991 Chevy S-10 4WD pickup (184k)
2000 Grand Prix GTP (142k)
2002 GMC Yukon (163k)