OK, I have read all posts remotely connected to my issue.
Recently, I allowed my 1988 (V12 5.3 HE CE ignition) to idle for about 30-45 minutes without the AC on. He apparently over heated and died. I waited about 3 hours, went back and he instantly fire up.
From there, any time he got hot, the ignition amp got so hot it burned if touched.
I replaced the amp module: issued continued. Replaced the ignition coil (upgraded from 2 coils to 1); issue continues. Ordered brand a new AB14 ignition unit from UK and installed it. (While awaiting the new amp, all spark plugs replaced, distributor cap and rotor cleaned, wires checked for resistance, and insured all connections, grounds, clean and tight.)
Slightly modified problem still persists! Got the engine to start (smoother than before…) but died after 5-6 minutes. Would not re-start; waited 5-10 minutes, he started, but died after a short time.
Now, a couple hours later, went out to try again but (completely cold) will not start (no spark). So, it does not appear to be a fuel issue. Amp, coil, plugs, wires are new. All connections clean and tight; timing is good. So, why do I get spark one minute and not the next?
Tomorrow, I will check and test the pick up unit; and, insure it has the correct gap.
Help!
Is the ignition module a GM/AC Delco one?
I had a new aftermarket module that failed in half an hour.
You should also check the coax wire that goes from the module to the ECU, it gets brittle and can have shorts.
Also the cables and connections between the dist - ignition module - coil.
And check/clean all ground connections.
Good luck.
That sounds like the Hall Effect sensor in the distributor may be going open circuit intermittently.
The pickup triggers the Amp, which triggers the coil.
You need to monitor each device output to see where the trigger, or high voltage power is failing.
The new AB14 amp is Lucas and it is putting out a great spark.
Just started him this morning… took slightly longer than normal to fire. Ran about 6-7 minutes and died. No sputter, just went down to zero (not quite like ignition key turned off).
I do not see a “coax” wire… where does it originate? 6 connections at the amp: + & - to coil; 1 to tach; 1 ECU; 2 to distributor. The ECU wire is a plain thin wire in good shape; not what I’d call “coax”.
But I am also going to check if Fuel is being shut off by ECU. Where does the vacuum line connect at the engine?
If I should order a new pick up module, is there a brand that is preferable/best? Or is a Standard Ignition part OK?
Gonna open up the distributor and test everything. Thanks for your input!!
Non AC Delco modules can easily shut down when overheated, I have witnessed it too. When engine shuts down, I’d try to cool off ignition box and see if it fires up again.
It’s not the amp any more. This new unit was not hot at all after car ran and then quit. My old unit (with Delco module) did get hot, very.
The vac line to the ECU connects at the balance tube between the two banks; the nipple and hose is a bit hard to see from above; it’s almost on the underside of the balance tube.
If the hose is broken or disconnected the result is massive over-fueling…which doesn’t sound like what you’re experiencing. But, still, it’s a good practice to check the hose on general principles.
It should be right alongside the AB14 amplifier; the eyelet is usually grounded by one of the amplifier mounting bolts. It’s a very thin white wire with coax sheathing.
Cheers
DD
I’m 99% sure I used Standard brand and it works fine and has for several years
To be honest I’ll wager that there’s only one company still making these and the same part is being sold under several different brand names
Which bring to mind something I’ve wondered about…
Are the brand new AB14 ignition amplifiers, such as Joe purchased, still being made with the GM/Delco module?
Cheers
DD
I bought an AB14 box four years ago from SNG. Inside was a no name ignition module. I swapped it out for AC Delco.
I’ve seen my AC Delco run fine at 190F. I’ve seen a no name module cut out at 160F.
And I’ve had an AC Delco quit on me in 10 minutes when i forgot to put heat sink paste on it.
You don’t actually know that…it may be true, but you need to test to be sure.
Check the Hall effect sensor output is constant, especially when the engine stalls.
If the Hall effect sensor is sending voltages to the Amp, check the Amp is switching the Coil…etc.
It’s probably easiest to work backwards from the coil.
Is there a spark?
Is the coil being triggered by the Amp?
Is there power and Gnd at the Amp?
Is the Hall effect sender creating voltage signals?
Lack of splutter indicates an ignition issue, as opposed to fuel, but a simple test would be to wait until the engine stalls, check spark then fumigate the intake with petrol and see if it runs.
Issue SOLVED!!!
Replaced plugs, wires, coil, complete amplifier, pick up module and cleaned cap & rotor (they’re relatively new). I found the pick up module to intermittently quit. Got a new one from Welsh.
While I waited for my module, I traced the little thin wire and found a break. Repaired it but that did NOT solve my problem.
Drove around yesterday: amp stayed cool, he fired right up every time, never quit.
However, when the issue appeared, and I got him going for a bit, bank B developed a miss, which is why I replaced all the plugs and wires. And I now still have the same missing in bank B; A is solid. Checked the injectors and they sound good. Fuel pressure is good. And I put in injector cleaner every time I fuel up.
I have the plugs I took out and know that 2 plugs were fouled, another borderline.
Now I have to find out why the missing did not clear up…
The Nimbus story continues…
Thanks every one!!