96 blazer is driving me mad. No spark~
#1
03-30-2014, 09:19 PM
96 blazer is driving me mad. No spark~
ok... This thing is about to be set on fire. It will be a true blazer, then!
Here's some back story:
I was commissioned to swap motors on a blazer. Donor vehicle had been wrecked a few (yes, more than once) times in the ice storms we had here in Tx. That vehicle was a 1995 GMC Jimmy 4WD. So the guy who put me on the job bought a very clean 1996 4wd blazer to swap the motor into.
Some of you are laughing right now because you know it's not that simple.
Got the engines out, and swapped the heads. 150+ across all cylinders. Back into the truck it goes. All bolted up ready to go. Except, it won't start. I wasn't too concerned at that point because it's easy to over look something at the end of a tiring day. No big deal. Come back another day and start from scratch. Compression, fuel, ignition.
Ignition is the problem. It's very intriguing, actually. It sparks once... Maybe twice on random at the plugs. What gives? Coil is sparking away all day with no hesitation.
Maybe we upset the crank sensor? Replaced it with the other one. Nothing.
Maybe it's the cap and rotor? Tried the other ones that had less than 5k on them. Nothing. Then we bought new everything. Cap, rotor, plugs, wires, coil, and distributor.
Still doing the same thing. I don't know where else to look at this point. I've never seen anything like this. I've worked on several blazers/jimmys/4.3s period and have never had this much trouble.
In conclusion:
Motor swapped a blazer with a rod knock. Is sparking 1-2 times randomly at the plug, and always at the coil. Getting fuel, has good compression. Have replaced coil, cap, rotor, wires, plugs, and distributor with no change.
Help.
Here's some back story:
I was commissioned to swap motors on a blazer. Donor vehicle had been wrecked a few (yes, more than once) times in the ice storms we had here in Tx. That vehicle was a 1995 GMC Jimmy 4WD. So the guy who put me on the job bought a very clean 1996 4wd blazer to swap the motor into.
Some of you are laughing right now because you know it's not that simple.
Got the engines out, and swapped the heads. 150+ across all cylinders. Back into the truck it goes. All bolted up ready to go. Except, it won't start. I wasn't too concerned at that point because it's easy to over look something at the end of a tiring day. No big deal. Come back another day and start from scratch. Compression, fuel, ignition.
Ignition is the problem. It's very intriguing, actually. It sparks once... Maybe twice on random at the plugs. What gives? Coil is sparking away all day with no hesitation.
Maybe we upset the crank sensor? Replaced it with the other one. Nothing.
Maybe it's the cap and rotor? Tried the other ones that had less than 5k on them. Nothing. Then we bought new everything. Cap, rotor, plugs, wires, coil, and distributor.
Still doing the same thing. I don't know where else to look at this point. I've never seen anything like this. I've worked on several blazers/jimmys/4.3s period and have never had this much trouble.
In conclusion:
Motor swapped a blazer with a rod knock. Is sparking 1-2 times randomly at the plug, and always at the coil. Getting fuel, has good compression. Have replaced coil, cap, rotor, wires, plugs, and distributor with no change.
Help.
#2
03-31-2014, 05:16 PM
The moderator "Captain Hook" has addressed this issue many times & from what I have gathered, mixing different year engines with different year PCM's might be your problem and possibly an "Engine Re-learn" is possible. Look him up & good luck. You're in deep.
Thread
Thread Starter
Forum
Replies
Last Post
timmi79
Paint, Body, & Interior
1
01-06-2010 10:52 AM