Troubleshooting???

[RR383]

:huh:
Gentlemen...I need some troubleshooting insight.
Scenario...went to start the runner this afternoon as I usually do to warm it up...something went away???? In other words, I've been watching my electric choke function on the Edlebrock carb to ensure its doing its job, closing over the upper air horn, pulling off and opening as it should...and the fast idle cam set satisfactorily...on initial start-up...BUT today immediately after the engine fired up for a second or two it died and I was unable to get it to re-fire.
Since I brought the car home a month ago this never has happened...each and every time it started up and idled w/o any issues.
I pulled the distributor cap and didn't find anything unusual....neither the rotor, nor the cap appeared burnt. This car has all new aftermarket plug wires and appears to have a stock coil. Battery turns the engine over w/o issue....although I connected my battery tender to ensure the charge was up to snuff.
How do these Gremlins intrude on our territory w/o giving up any signs of a problem?
Seriously, I'm not sure where to look.....

 

[Ranger]

Pull a plug wire and ground it. Listen and/or watch for a spark to be sure you have fire to the plugs.

 

[Basketcase]

points or electronic ignition? if electronic, probably the ECU box.
and.....are you getting gas?

 

[quikbird]

Gremlins are par for the course with our old roadrunners. Need four things to get car running; gas, air, spark and compression. Pick one and start there. Does it have gas, as Dave suggested ground a plug wire (or use a plug tester) and see if have a spark, is the throttle blade in carb open enough to get air in, compression should not have changed so problem probably not there. A fail in any of the systems points you in area to start backtracking till find fail point. Good luck and if get stuck ask away. We'll help. :huh:

 

[dutchrunner]

When turning on key and you look at carb (no aircleaner) does the choke do any thing>

 

[RAINMANYEH]

Maybe something as simple as a clogged fuel filter?
Fuel pump gone or going bad?
Issue with the carburetor accelerator pump?

 

[RR383]

points or electronic ignition? if electronic, probably the ECU box.
and.....are you getting gas?

No points...its an earlier form of electronic ignition. Is the ECU mounted on the firewall? No MSD

 

[RR383]

Gentlemen...call it fate...call it jumping through my #@* to quickly...but a few minutes ago I went out to the garage...took the battery tender off the now fully charged battery....checked the fuel gauge for movement after turning the key to on...moved to a little over 1/4 tank...checked for power and movement of the thermostatic choke...power and subtle movement to open...check.
The car cranked strong and started...and after clearing itself of excess fuel it idled fine. After the engine reached thermostat temp I shut it off and as soon as I turned the key it fired right up on the first lick.
Who the $#@* knows...but I know one thing I really appreciate all of you coming to my rescue...thank you!

 

[69hemibeep]

Pull the fuel line from the carb, add some hose if needed, put it into a coffee can or something crank for 15 seconds and see what you get. Also with the key in the run position check for voltage at the coil.

 

[Ranger]

I'd suspect the choke. I've found mine (same ignition & carb) to be rather finicky starting if the choke is not adjusted just right.

 

[Basketcase]

when my car had electronic ignition,sometimes it would start, sometimes not. sometimes it would quit going down the road. hard to say where the ECU box is mounted, as it would have been done by the PO.

 

[Big John]

Probably just flooded it.

Next time, wait a few minutes. Push the gas pedal to the floor and hold it (do not pump the gas!!) turn the key and see what happens.

Everybody is used to fuel injection cars that never flood.

 

[Basketcase]

not the angry old white guys.......

 

[69hemibeep]

John is an angry old wise guy

 

[quikbird]

I'll agree with that. :bump:

 

[Josh]

Hi guys, I know this is an old thread but some of the problems I am having have been mentioned in it.
She will start sometimes then cut out. Have tried grounding the lead and get no spark. No obvious loose connections.
I'm thinking it could be the electronic ignition unit mounted on the firewall.
Is there any way to test these?

 

[Basketcase]

first pull the ECU and clean the mounting surface...these need a good ground.

 

[Josh]

Have tried connecting to the wiper motor with some alligator clips to try and help with grounding. Results have been 50:50 so I am thinking earthing.

 

[Big John]

Hi guys, I know this is an old thread but some of the problems I am having have been mentioned in it.
She will start sometimes then cut out. Have tried grounding the lead and get no spark. No obvious loose connections.
I'm thinking it could be the electronic ignition unit mounted on the firewall.
Is there any way to test these?

First, get yourself a digital multimeter. One of those $25 ish meters from Harbor Fright will work out well. A cheap $5 will work too, but spend a few bucks and get a better one for your garage toolbox and the cheap one goes in your trunk toolbox.

This link has one of the better explanations of how the Mopar ignition works. Read a little and get down to the troubleshooting section.
http://classicwinnebagos.com/forum/index.php?topic=3424.0

People will always suggest changing parts... That's an expensive way to do troubleshooting.... Lots of new ECUs have been bought when the problem was really a bad ground or a lose wire. That said, you should be carrying a spare ballast resistor in your car because they do fail occasionally. It may get you home and having that spare is an easy way to do a quick diagnosis.

 

[Russ69Runner]

Big John hit it on the nail head. Always carried a spare of each. The resistor use to be the first thing to go. The ECU was just insurance when on the road and the resistor.