[Vanube]

318cu manual trans, Holley 2280 rebuilt, rebuilt distributor, many many new parts, Holley electric fuel pump, aftermarket voltage regulator set at 13.5 or so? Is this to high? 13.5 volts going straight to coil and HEI?

I've had a problem with this van bogging out at
highway speed going uphill under load.

I put the GM HEI conversion on this vehicle. I seem to have burned through a few coils now. And I've tried different brands for the ignition unit itself. However, that's not the problem I'm dealing with now. I don't think.

Today the bogging problem that usually only occurs at highway speed started to happen while driving City speeds. Eventually the van continuously bogged out every time the accelerator was pushed. Then it would not start.

Before the van stopped starting - - the brake pedal got very stiff and hard to push. Eventually, I was able to start the van a few times and only idle, any fuel application and the van would die again. The brake pedal has remained difficult to press down even after the van has not started. The engine actually backfire a few times when I was reluctantly able to start and idle it a few times.

I detached the brake booster vacuum line and blocked it off at the carb.

For some reason I feel like this is a fuel delivery problem or maybe a vacuum problem inside the brake booster leak. But then why not healthy running engine after blocking off the brake booster?

Sorry if I missed anything. Thank you guys!

 

[Bob Lincoln]

You have multiple problems.
What kind of voltage regulator is set to a specific voltage? Voltage is adjusted within a safe range by the ECM. Setting a fixed voltage will not provide proper charging, and either too little or too much voltage at any given time to the electronics. Start by reinstalling factory system.
Stiff gasoline pedal may be a misadjusted kickdown rod or cable to the transmission. If it's misadjusted, it won't allow the throttle to open all the way.
Bogging may be a clogged catcon or carb problems.

 

[68RT]

You have multiple problems.
What kind of voltage regulator is set to a specific voltage? Voltage is adjusted within a safe range by the ECM. Setting a fixed voltage will not provide proper charging, and either too little or too much voltage at any given time to the electronics. Start by reinstalling factory system.
Stiff gasoline pedal may be a misadjusted kickdown rod or cable to the transmission. If it's misadjusted, it won't allow the throttle to open all the way.
Bogging may be a clogged catcon or carb problems.

Stiff "BRAKE" pedal! Usually means no vacuum to brake booster. 13.5 volts measured where?

 

[Vanube]

Wait what? This kind. Bypassed ballast resistor. Stiff brakes not accelerator. Braked got stiff right before the van dies and would not restart.
*rebuilt carb
* no cat

 

[Vanube]

GM HEI conversion

GM HEI conversion (A 'How To')

OK, you asked for it, so here it is…. ;) (WHY do I want to do this ANYWAY??? ** See end of article) STEP BY STEP to convert your Mopar ignition over to a GM High Energy Ignition system. (The example here is for a small-block V-8 engine, but with exceptions for mounting the module, because...

www.dodgetalk.com

 

[ImperialCrown]

I agree with a fuel problem. Is the electric pump 'in-line' from the fuel tank? Could the problem be inside the fuel tank?
On a 37 year-old vehicle, the inside of a fuel tank can be an ugly sight. Plugging of the inside pick up tube sock, debris at the tank bottom and stuff growing on the walls in the tank may be a suction clog or restriction for the pump.

 

[AHBGuru]

Wrong carb, wrong voltage regulator, wring fuel pump, wrong ignition system.

Sell it.

 

[valiant67]

To me, it sounds as if the van was never properly in tune. And it's just gotten worse now.
Once you swap to a different ignition, you've got to consider base timing, mechanical advance, and vacuum advance curves.
Then once you have timing straightened out, then you need to tune the carb so it's not too rich or too lean. Reading the spark plugs would be the key here. If the original stumble was not from timing, it was from the carb - rebuilt or not.
The coil is burning up likely because there is no ballast resistor. The stock Chrysler coil will burn up without the resistor.
The brake pedal is hard because the engine is running poorly and not producing any vacuum. Once you get the engine in tune, the brake problem should go away. This assumes there was no damage to the booster or check valve at the booster from the backfires. It also assumes the low vacuum is not because there is a severe exhaust restriction like a plugged catalytic converter. It also assumes the engine doesn't have a sloppy timing chain (or even jumped time).

There's nothing wrong with building from a lot of various non-factory parts but you need to properly dial the stuff in so it runs right.

 

[bguy]

Fuel issue

 

[mopar56]

I agree with fuel issue to start, check filter and pressure report back.

 

[dana44]

You can add checking the float level itself to the list. Check for vacuum leaks. She might idle with a vacuum leak, then bog/die when additional air is introduced with gas pedal being pushed. Bad vacuum to the brake pedal itself increases this problem that already exists.

 

[Laser86]

Back-firing sounds like a timing / timing advance issue.

Have you measured the mount of slack in the timing chain ? It's an 85, how many miles are on this engine ?

I would just leave the vacuum port blocked off for the brake vacuum booster and work on the run-ability issue.

 

[ImperialCrown]

Lean mixtures or grossly advanced ignition timing will tend to pop-back through the carburetor.
Rich mixtures or retarded ignition will tend to back-fire out the exhaust.

 

[Vanube]

Well, bad ignition module. I have to figure out how to wire this module and coil properly so I stop burning through both. Any help on this would be great. It's the four pin GM module with e-core coil rig up (very common mod aloy of you are probably aware of). Measuring 14v at coil at idle. Wondering if coil causes module to pop or vice versa? How can I test my block to firewall grounding? I just re ran all wiring - changed from 14g to 10g- module is mounted and grounded well to heat sink on fire wall. Used enty of special Grease on the backside!

It's correct that I have not timed this this properly. I have not got the vac advance figured out. It has been plugged. It's the only way I've got this this to run well. I haven't figured out how to do this process correctly. Everytime I try to plug in the vac advance the van runs terrible. Can someone suggest a write up? I'm new to alot of this.

Also, Very blocked up fuel filter on the electronic pump. This van will be getting a new tank ASAP.

Also, vaccum on all ports test good. So, brake booster must be shot. I will do more tests on the booster to confirm.

 

[valiant67]

I've never messed with the HEI stuff, so I can't speak to that. I'd assume there should be sites detailing that install.
If you're not running a ballast resistor, you've got to have a coil that can live with full voltage all the time. The stock coil won't live under those conditions.

If the engine won't run with vacuum advance connected, the vacuum advance may be connected to the wrong port. The proper port for vacuum advance should have little (if any) vacuum at idle. The port should provide increasing vacuum as the RPMs increase. Or the base timing is way off, or the advance way too rapid.

 

[valiant67]

This site is helpful, but you've added the HEI which means you'll have to find out specifics about it when following the process:

Cal Tech

Tuning from scratch: How to get your newly-built Mopar running razor sharp. This installment covers ignition timing and advance.By Richard Ehrenberg, SAEBuilding your Mopar to pure, dead, OEM-stock?All the tuning info you need is in the FSM,

www.moparaction.com

 

[Laser86]

How many miles are on this engine ? Have you checked the amount of slack in the timing chain ? If you have excessive play in the timing chain you are not going to be able to get the engine to run smoothly.

Vacuum advance needs to be operational for the engine to accelerate properly under load.

You should be able to measure the " potential voltage " across point A to point B with a DC volt meter, I would expect to have a minimal reading, if any.