Sounds like after it gets hot, something is separating. I would check the connections on the relay, the harness connections on the firewall engine bay side. Also, check the ground on your ECM, and check the connection plug, if its been sitting, I would unplug it and check for corrosion on the contacts, also the back of the ECM is grounded to the fire wall, makes sure there is no rust between the firewall and the ECM.
Alright all, I am taking this list above and adding a few other things to it to check when I finally get this car here (hopefully in the next week). My list includes the following some of which are not likely but while I’m at it I may as well confirm they are not an issue.
1. Ignition issue? ECM, coil, ballast resistor?
2. Fuel issue?
3. Compression issue? it has NOS on it and my ex brother-in-law was the last to drive it
4. Timing chain jumped?
5. Distributor issue?
6. Ground issue?
7. Wiring issue?
8. Bulkhead connection issue?
9. Starter relay?
10. Cap, rotor, wires, plugs issue(s)?
11.
Here I have posted the description of the engine from the previous owner (Cokebottlekid, on Moparts)... and some guesses on what he felt like the issue was.....
“The fuel pump is on (kill switch is on) and it is running yes? Filters aren't clogged etc? Next time it does this check to see if the carb still has fuel (accelerator pumps squirting etc) and check for spark. I never really had any spark problems or resistor issues, I just always carried a spare just in case.
My guess is it's actually flooding out. If it's been sitting for a while you might want to pull the carb apart and give it a good cleaning. Make sure the floats aren't stuck etc. Also note it is a manual choke carb and it's set on open at all times, never was a problem much in CA but if it's real cold over there it might be a bear to keep running when the motors cold. Hope that helps some, try checking the basics first to determine what the problem is, no spark, no fuel, or too much fuel.
As far as what I'd done to the car....
I built the motor, .030 over 318
-stock crank (.010) , stock rods all reground and resized
-KB hyper pistons
-Total seal gapless rings
-New stock oil pump, stock pan
-All new seals and plugs etc
-Heads are I think 587 J 360 castings, they have 2.02 intakes, all valves are some no name brand stainless I bought from Mancini.
-Cam is a crower 31204 grind hydraulic flat tappet, it's .474/.480 218/227 @.050 on a 108 LSA. I bought the entire kit for that cam including springs, and retainers.
-Intake is a 340 air-gap
-Headers are 1-5/8 headmans
That pretty much rounds out the motor...
As far as the fuel system it has a holley blue pump mounted in the rear, has a mallory bypass style fuel pressure regulator up front. The supply side is 3/8 aluminum the return is the stock 5/16 steel line.... now that I think about it do you still have the vacuum line hooked up to the fuel pressure regulator? It's kind of a long story but basically I tuned the nitrous system by upping the fuel pressure rather than buying new fuel restrictors every time. As a result it needed to be like 12 or 14 psi at WOT to work well, it worked fine at WOT but that's a little too much pressure for cruise so I hooked up the vacuum line to give the fuel pressure a relationship to the load. When the car's running it should be like 8 or 9 psi. If you've taken off the nitrous system like you were going to I'd probably drop the pressure down to 8 or 9 static and eliminate the vacuum line.
The carb is a holley 750 I rebuilt myself. It's jetted a little fat for cruise IMO. Also... for some reason that thing just LOVED accelerator pump, when I first put it on the stock pumps that came with it were far too small. When I was driving it I had full 50cc accelerator pumps front and back. As I left it I believe I put a 30cc cam in the front, but it may like a 50cc better.
That pretty much rounds out the fuel/motor mods. The ignition is pretty much stock except for a MSD coil and a MP chrome box. Never had a problem with it. However those ignition wires are on the old side, might be time for some new ones.”
With all that being stated I can assure you the NOS will be coming off of this car, I have never liked the idea of NOS and it’s go or blow tendencies. I would be way more likely to add a turbo than use NOS.
