rickyellow zee Posted October 28, 2015 Share Posted October 28, 2015 I installed a gm hei for my L28ET 78 280z as per the writeup skittle provided on another z site and it will not Rev past 2000 rpms. The car started normally but once i Rev it sputters like it's hitting the Rev limiter. also backfires. ANY ideas? Thanks. Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted October 28, 2015 Author Share Posted October 28, 2015 Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted October 28, 2015 Author Share Posted October 28, 2015 pics above. Thanks Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 28, 2015 Share Posted October 28, 2015 Cause, effect, correlation? Did you install the module to fix the 2000 PRM problem, or for some other reason? Why did you install the module, and what was it doing before you installed it? Describe the engine management system also. That will help. Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted October 28, 2015 Author Share Posted October 28, 2015 (edited) I have an issue with the car sputtering out and dying with the stock ignition components. When cold the car has zero issues. The car gets hot... it dies, let it cool for 15 minutes it starts and goes like nothing happened. After doing research and asking questions many think its related to the stock ignitor(module) going bad. In the colder months the car runs fine, no issues..Runs like a bat outta hell all the way through the rpm's. I figured I would replace with a GM HEI to fix the problem of the car dying in the warmer months. Engine management is stock. Edited October 28, 2015 by rickyellow zee Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 28, 2015 Share Posted October 28, 2015 You might switch the G and W wires. The pictures in Skittle's zcar.com writeup are gone so can't tell what he found that worked. But in normal use, if you get G and W swapped, timing will be off. It won't hurt anything, but it might just make the triggering more consistent. If you want to be sure that it's tied to the HEI module, put the old ignitor back on and see if the new problem goes away. Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 28, 2015 Share Posted October 28, 2015 You might also add a condenser/capacitor to the W wire. The HEI module is supposed to work from zero crossing, positive to negative. But in the the ignitor swap it's actually working from positive TO zero, the ECU signal. So it's not quite right for the application and might be more susceptible to noise. Just a guess. I've fixed tachometer problems with an extra condenser. You might also move the ground point for W farther away, and/or just make sure it's a good ground. Maybe move the whole assembly away from the coil to reduce potential noise. Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted October 29, 2015 Author Share Posted October 29, 2015 Im gonna start with moving grounds first. I keep reading about the grounds having to be solid. If the grounds don't fix the issue then I will try swapping W and G wires. The car worked fine yesterday but not today after the swap. Must be the HEI. If all fails then old (un)faithful goes back in. Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted October 30, 2015 Author Share Posted October 30, 2015 I moved the ground to the coil bracket, didn't work....swapped the g and w wires, car would not start. Swapped the g and w wires back and it started but problem still persists. I think maybe something is wrong with the hei. I'm going to put the old one back on and see if things go back to the way they were. Stumped. Quote Link to comment Share on other sites More sharing options...
rickyellow zee Posted November 1, 2015 Author Share Posted November 1, 2015 (edited) The old one is back on. I cleaned up the wiring and went with a pertronix coil. Problem went away. car revs up well and pulls strong. I'm not sure how things will go when the ignition module heats up again in the warmer months. Time will tell. I guess the HEI I used was too cheap? Dunno. Edited November 1, 2015 by rickyellow zee Quote Link to comment Share on other sites More sharing options...
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