Hello all, I’m new to the forum but not new to the gmt400. I’ve had my truck five plus years and loved every minute of it even though a lot of those minutes have been painful.
So my current situation is my truck has 180k miles on it, in the past few years it’s gotten intake gaskets, new spider injection, new fuel pump, new msd distributor, new coil, new exhaust including headers and 02 sensors. It just got a new crank sensor flexplate and starter.
it was also timed properly with a scanner and is within 1deg on the cam retard so the timing is dam near perfect.
Last week it threw a p300 code and was barley drivable but it got me from a to b. I figured the wires were getting heat soaked from the headers we put on it so I changed the wires for a set of new ones from msd, the same wires I’ve been running without a hiccup for two plus years in addition to that I put heat insulator boots over the plug boots to protect them from the heat of the headers. Needless to say the truck ran like a sewing machine cold after I installed the wires drove it around no problem got it up to temp.
come out a half hour later she barley started and stalled when I shifted into gear. The one thing that was never changed and looked original was the ignition control module so I went ahead and changed that being it had 180k miles on it good possibility it was bad.
now the issue remains, she runs mint and I mean she hums without skipping a beat when she is cold, as soon as it heats up forget about it, it feels and sounds like it wants to explode. I’m at a loss with this thing, I need it to get itself by for another year ish, then it’s getting a 5.3 lm7 swap that’s sitting in the garage waiting on the time
So my current situation is my truck has 180k miles on it, in the past few years it’s gotten intake gaskets, new spider injection, new fuel pump, new msd distributor, new coil, new exhaust including headers and 02 sensors. It just got a new crank sensor flexplate and starter.
it was also timed properly with a scanner and is within 1deg on the cam retard so the timing is dam near perfect.
Last week it threw a p300 code and was barley drivable but it got me from a to b. I figured the wires were getting heat soaked from the headers we put on it so I changed the wires for a set of new ones from msd, the same wires I’ve been running without a hiccup for two plus years in addition to that I put heat insulator boots over the plug boots to protect them from the heat of the headers. Needless to say the truck ran like a sewing machine cold after I installed the wires drove it around no problem got it up to temp.
come out a half hour later she barley started and stalled when I shifted into gear. The one thing that was never changed and looked original was the ignition control module so I went ahead and changed that being it had 180k miles on it good possibility it was bad.
now the issue remains, she runs mint and I mean she hums without skipping a beat when she is cold, as soon as it heats up forget about it, it feels and sounds like it wants to explode. I’m at a loss with this thing, I need it to get itself by for another year ish, then it’s getting a 5.3 lm7 swap that’s sitting in the garage waiting on the time
