djcondo

the knocking can be piston slap. im still young and dont know too much about engines but i haveread a few articles about it. I had piston slap in my jeep and thought it was a lifter and then blew the piston and had to do a complete rebuild. i guess GM's are known for this.

750HPGT

thanks adder ill try that. today I went out and started it up ran fine drove it 5min ran fine. I wish it would not come and go any other ideas? oh the fuel filter is new.

8banger

Unless you replaced the Modular pump assembly with a A/C delco or a Delphi unit....CHECK the fuel pressure just to make sure its NOT the problem....again...thats where I'd start...

95 331GT

I've worked on about 1,000 of those freakin chevy trucks...I'm sorry you own one. Before you shell out money to take it to the dealer make sure you check for spark when it's dying. You don't have a fuel problem although that is common with those trucks.I'm not sure what the ticking noise you're hearing is but it sounds to me like you've got a bad ignition module, pick up coil, or ignition coil. All of these parts were problems on the earlier 90's trucks. The codes in the computer would be valuable information so find that first and work from there. Like I said though it sounds like you're chasing an ignition problem.

stang8689

It's a Chevy

reddogg

if the truck has a distributor i'd start with the ignition module, takes about 15 minutes to take it out and your local parts store will test it for free.

kilgorq

ICM all of the way. The Ignition control module in the disty has a very high fail rate and acts just like what you are describing. The ticking is due to spark issue. I have fixed it on about 20 of these. Make sure when the test it they lightly tap on it with the back of a screwdriver or something like that.

750HPGT

sorry adder but nope. ill have it hooked up to a computer tomorrow! thanks for the help!

750HPGT

i almost forgot. I drove the truck the 10min toand 10min home from work today ran fine. is their anyway to test the ICM with a DVOM? thanks

750HPGT

Had it hooked up to the snap-on modis today NO CODES set, no freeze frame nothing!! it has ran fine the past 2 days. now what?? thanks for help!