Can't make it up my driveway

[Limey]

Hi you'll,

I have a 305 stock engine 131k original milea in my '85 K10. I've had it for 10 years, never had a problem. 3 weeks ago the engine stalled while I was running about. Kinda like running out of gas. I let the engine cool, and limped home. No spark.. I Replaced the ignition module, and she fired right up. Thought I'd fixed it. The issue is when I load the engine it begins to misfire backfire, and run like crud. I will barely make it up my driveway. Timing is good. I replaced the spark plug wires (MSD), Still the same. Spark plugs are old, but not fouled. She was running fine, until I got into the distributor. What should I do next?

Thanks in advance

Limey

 

[Snoots]

Plugged Catalytic converter.

 

[Big Chip]

I just had the exact same issue. I ended up replacing the module again along with the coil, cap and rotor. Problem solved but I'm not sure what fixed it.

 

[Vbb199]

Cat is all packed up with ****!
I bet you can lay on the gas pedal and it sounds like your motor is in a tunnel 10,000 feet down doesn't it?!

 

[Limey]

No catalytic converters. Its not necessary in GA.

 

[Ricko1966]

Did you buy a cheap module?If so try a better brand. But first are the plug wires on in the correct order 18436572? A bad coil a bad rotor, wires etc. will kill a module so check and or replace those also.
Kinda like running an engine with a junk oil pump ,replacing the bearings that wore out because of the junk pump, but leaving the junk pump in it. I'd make sure the module was the problem not a symptom.

 

[Limey]

I got the module from NAPA, $40, so I wouldn't call it cheap. I checked the coil and it met specs. Firing order is correct. The module is a 4 pin, and it plugged into another component inside the cap. I think its an ignition capacitor?? It idles just fine. Revs up when I step on the gas, just goes kaputt when the engine is under load.

 

[mtnmankev]

I would suggest you verify the timing chain isn't stretched.
If you have 100K miles on an engine and the timing chain/gear set has never been touched, you can set the ignition timing spot on, but the valves will be running late, and resetting the timing for the distributor won't correct that.
If you need some specific instructions how to perform the test, we are more than happy to help.

 

[Vbb199]

That was my next thing.
Iginiton module, but it sounds like you got an. OK one.

 

[Shorty81]

Check fuel filter

 

[mtnmankev]

Check fuel filter

Also a very good suggestion.
It may be a coincidence the problem showed up in conjunction with your distributor work.
It's happened to me many times ..........

 

[mtnmankev]

I may sound presumptious, but I hope you kids applied a coating of white heat sink compound to the new ignition module when it was installed.
Heat can injure or kill a module REAL QUICKLY without the compound.

 

[Limey]

Thanks for the suggestions. Fuel filter... i will check that next. It may be coincidence, but it has never been changed since I've owed her.
As to the timing chain, I will also check that. And search for the instructions to do so. But like I mentioned it idles fine, even revs high when I open the throttle. Would timing show up under load?

 

[Limey]

yes sir, i put a good coat of heat jell on.

 

[mtnmankev]

Thanks for the suggestions. Fuel filter... i will check that next. It may be coincidence, but it has never been changed since I've owed her.
As to the timing chain, I will also check that. And search for the instructions to do so. But like I mentioned it idles fine, even revs high when I open the throttle. Would timing show up under load?

If you haven't changed the fuel filter in 10 years, I would suspect that highly, especially knowing how the quality of gas has gone downhill over the years.
I don't recommend changing parts and hope it cures an issue, but my opinion is the engine deserves a new gas filter, and they aren't expensive.
An engine can idle decent and rev with a bad timing chain, but under load it would definitely be noticeable.

Rotate the engine until the timing mark is at 0 degrees TDC.
Remove the distributor cap.
Make a mark where the rotor points.
Manually rotate the engine the opposite direction with the crankshaft bolt slowly, and note how many degrees of crank rotation it has just until the rotor starts to move its opposite direction of rotation.
A couple of degrees is to be expected and acceptable.
But, if the crank turns a bunch before the rotor moves, the chain and gears will need to be replaced.
I have bought many cars over the years that didn't run, or didn't run right, and all it took was a timing set to fix it.
Common theme between them all, 100K or more miles and never been touched.

I hope we are helpful to you in solving your truck issue .....