Miss only when the truck is warm.................

[SnakeEater]

I just had to replace my wires due to one of them melting on the header...I was getting a real bad miss which lead me to the wire being toast..NOW, after new plugs and wires, im getting a nasty miss which only comes in after the truck is warmed up...Ive got a new Ignition control module put in 2nite and also checked all my vacuum lines and elect. connections of course, but still getting the miss.....Im at a road block here of where to go next.....Could my timing be off possibly, or could my coil have takin a shit due to the spark arching on the header?? its a MSD 7al-2 w/ a HVC pro power coil and im thinking I might have shorted out the coil?? IS there a way to test this, also, if anyone else has had this same issue, what did you find out???

Im guna check my timing and fuel pressure 2maro, but any other suggestions would be apreciated...Oh yea, the miss i get is a nasty back fire sometimes and again its only when the motor is at operating temp............

 

[SnakeEater]

Re: Miss only when the truck is warm.................

anyone?? anything??

 

[midnightbluS10]

Re: Miss only when the truck is warm.................

Did you check timing and fp?

 

[VermontTy]

Re: Miss only when the truck is warm.................

I'd toss a new cap and rotor at it while you're trying to solve the issue. Two less variables, and a good idea as long as you've replaced everything else.

 

[cloneman315]

Re: Miss only when the truck is warm.................

could be ignition module they are cheap change it,also common for the distributor itself to go bad,i had that happen to me i chased it for months,the shaft gets cracks in it and the spark can jump

 

[VermontTy]

Re: Miss only when the truck is warm.................

could be ignition module they are cheap change it,also common for the distributor itself to go bad,i had that happen to me i chased it for months,the shaft gets cracks in it and the spark can jump

he said he'd changed the module, but from my parts store experience, I recall the occasional GM-style ignition module running top-notch on one or two tests, but once they heat up (and they DO heat up!), they'll fail. Might also be worth just pulling the module and taking it to the parts store for them to test 4 or 5 times.

 

[SnakeEater]

Re: Miss only when the truck is warm.................

Heres where im at....

New cap and rotor, plugs, wires and i.c.m.....Checking fuel pressure an timing tonite.. Am i able to hook my MSD box to my stock coil So I can rule out the coil??? What is an ideal fuel pressure to be at?? Im running stock injectors with a 2bar map only hitting 15lbs of boost....
Also, what parts dealers will test my icm for me?? called napa and autozone and they dont do it, at least the ones by me.......This problem sucks!!! I just spent 2 days this weekend rewelding my headers and exhaust only to get 1 good night of running out of it and now it sits again....

 

[purdaddy]

Re: Miss only when the truck is warm.................

SnakeEater, did you ever find a resolution to this problem???

 

[2fast4u]

Re: Miss only when the truck is warm.................

he said he'd changed the module, but from my parts store experience, I recall the occasional GM-style ignition module running top-notch on one or two tests, but once they heat up (and they DO heat up!), they'll fail. Might also be worth just pulling the module and taking it to the parts store for them to test 4 or 5 times.

Your right!..them tests are unreliable. I have brought many icm's into Napa, and they tested them, and tell me their good, but their really not. I have actually argued with the salesman about it. When they are installed in the distributor and under actual load and heat up in a normal fashion, they will screw up when they get hot if defective. They almost always check out on their testers. Even though the icm testers have a load test, it is not accurate. Been there, done that,.. so many dam times. I love going back to the store, and saying *I TOLD YOU SO!!!!*

 

[Don W.]

Re: Miss only when the truck is warm.................

FWIW I took my Sy to a well regarded shop and just paid them to put the truck on a scope. Turned out dist was flaky. Not failing exactly just not correct. Truck did run better after dist swap.