Possible, for sure although I think the problem is pronounced at idle making me lean towards either lifter or adjustment problem or vacuum leak. When driving and the rpms are up higher the issue almost goes away.
bad gasoline? (not!)
- Thread starter JD1964
- Start date
- Status
Show's how long it's been since I messed with LT1's....
Ignition Coil Module. Heat kills them. This is not anything valvetrain or mechanical. Purely Electronic.
Time for the LS Swap. 🙂
JD1964 this will be your problem and when you put the new one on, use washers or nuts behind it to space it off the Head, helps it last much longer. Done dozens of them back in the time I was working on LT1's.
Ignition Coil Module. Heat kills them. This is not anything valvetrain or mechanical. Purely Electronic.
Time for the LS Swap. 🙂
JD1964 this will be your problem and when you put the new one on, use washers or nuts behind it to space it off the Head, helps it last much longer. Done dozens of them back in the time I was working on LT1's.
Last edited:
Bad injector? Clogged injector(s) screen(s)?
If you can get hold of an injector pulse tool, you can connect it to one injector at a time with the engine off, pressurize the fuel rail, note the pressure, then pulse the injector and note the pressure drop. Repeat for each injector one at a time. Be sure and start the engine in between each injector pulse and pressure drop test to clear the fuel out of the intake. Basically if you got some crap that got past a bad or deteriorating fuel filter it might have lodged in the injector inlet screen at the fuel rail on engine.
Seems like you should easily be able to unplug one injector plug at a time while running too to help isolate which cylinder is misfiring or not firing at all, then you can inspect that plug, wire, etc..more closely.
HTH
If you can get hold of an injector pulse tool, you can connect it to one injector at a time with the engine off, pressurize the fuel rail, note the pressure, then pulse the injector and note the pressure drop. Repeat for each injector one at a time. Be sure and start the engine in between each injector pulse and pressure drop test to clear the fuel out of the intake. Basically if you got some crap that got past a bad or deteriorating fuel filter it might have lodged in the injector inlet screen at the fuel rail on engine.
Seems like you should easily be able to unplug one injector plug at a time while running too to help isolate which cylinder is misfiring or not firing at all, then you can inspect that plug, wire, etc..more closely.
HTH
The EEhack program I use with the laptop connected has some control features built in. One of them is cylinder cut out. I can manually drop any cylinder to try and isolate problems. It does this by cutting the pulse signal to the injectors. I’ve used it and I found equal reaction on all cylinders so I’m ruling out bad or clogged injectors or bad plugs. Those issues would be steady and consistent I think.
The suggestion of possible failing ignition control module is more likely than spark plugs or injectors.
The suggestion of possible failing ignition control module is more likely than spark plugs or injectors.
ICM failure is notorious for the LT1. MSD Blaster Coil and ICM is an excellent upgrade. Used to bolt them up spaced from the Head, car came back alive.
As far as I know the ICM is original to the donor car (94 z28). It had 120k miles on it. When doing the swap I added an extra large copper heat sink and spaced it from the head. I also moved the coil and module assembly from the driver’s side to the passenger side in order to make room for a modified power steering pump bracket.
I’ll definitely be considering the ICM as the possible culprit. I may even have a spare around here. Here’s the stuff mounted on the front of the passenger side head
I’ll definitely be considering the ICM as the possible culprit. I may even have a spare around here. Here’s the stuff mounted on the front of the passenger side head
Are you sure you don’t have that backwards?
Copper vs. Aluminum Heatsinks: What You Need to Know
Heatsinks play an important role in helping to cool electronic devices. Most heatsinks are aluminum, but some are made from copper. Let’s compare copper vs. aluminum heatsinks and look at a few different factors that play into aluminum's popularity.
www.gabrian.com
Also, here’s the side of that copper heat sink you don’t see while mounted on the car. Look at all those fins. That’s a lot of surface area to shed heat. I don’t think that copper heat sink is hurting anything.
Yea, could have, been a while.
So let me throw this at you..heat sink with fins is to dissipate heat. If there's no air flow in that little pocket between the head, heat can't move.
So let me throw this at you..heat sink with fins is to dissipate heat. If there's no air flow in that little pocket between the head, heat can't move.
- Status
Similar threads
