Help Tracking Down Starting/Running Issue

[katwalk]

I have had this truck for a few months now and it always cranked right up. A few weeks ago I drove it to the Squarebody Yard Party, about 80 miles away. When I was trying to leave, the truck would not start. I cranked on it for a while and it finally started - rough at first but then seemed fine after that. Over the next couple of days, on a couple of occasions while cruising down the road, the truck would fall on its face for a second or two then keep going. A few days later, I was out running errands and it and it would not start again.

I got it home and my first thought was carburetor. Long story shortened , I bought a rebuilt quadrajet for it. It is a later model QJet with the electric choke. I was having trouble starting it after installing the new QJet, so popped the cap off the Dist to find it a rusty mess - I was amazed it ran at all.

So, in goes a new Dist. I have checked and rechecked the timing to make sure I knew where top dead center was and the new plug wires were installed correctly - all good there.

I can not for the life of me get it to run. It cranks and cranks and sometimes acts like it wants to run but wont. One time I got it to run and it smoked like crazy out of the tailpipes. It idled roughly while I tinkered with Idle Air screws and distributor/timing then finally died.

I have looked into the carb while pressing the throttle and can see fuel flowing. I have pulled a plug wire and installed it on a spare spark plug and can see it sparking. I pulled the valve cover and can see the engine has not had the best life (sludge), so I am wondering if a stretched timing chain could be preventing me from actually getting the timing right. Thoughts? Ideas?

Thanks - Farrell

[Willys_MB]

I was chasing a similar issue. Do you have an HEI or an older distributor? I installed a NEW ACDelco HEI ignition control module and it died a few days later. I put in a USA made chip and it’s been fine since.

A lot of issues like this tend to be related to distributor and or timing, so I think you’re on the right track.

[katwalk]

Thanks for the response. I replaced a rusty old AC Delco HEI with a new Proform one from Summit. The cap on that new one was immediately bad so replaced it with another one I had and have spark at the plug. My thought is if I have spark at the plug then the control module must be good. Someone please school me if I am thinking of that incorrectly.

Thanks

[geezer#99]

Check your fuel pump output.
Pull the line off the carb and put the end in a quart jar.
Crank it over and it should fill the jar fairly quickly.
Should have a steady spurt.

[Boog]

What about spark plugs?

[katwalk]

Originally Posted by geezer#99

Check your fuel pump output.
Pull the line off the carb and put the end in a quart jar.
Crank it over and it should fill the jar fairly quickly.
Should have a steady spurt.

Thanks, I will check it.

[katwalk]

Originally Posted by Boog

What about spark plugs?

Just bought a new set, haven’t put them on yet.

[kwmech]

Check the rubber fuel lines for cracks

[dbm52]

you have a fuel delivery problem. Check for cracked fuel lines, plugged fuel filter, fuel sock on fuel sender coated or plugged. don't think you have a bad fuel pump usually would quit running. also on some carbs they have a bronze filter between the float & inlet although probably not the problem since it's in the carb & you replaced it

[katwalk]

Well that went south real fast. As I continued to dig into the running issue I was having, I learned more and more about this motor. The first sign that something was bad was when I pulled the cap off the distributor and the mechanical bits were so rusty I could not believe the thing even ran. I tried to remove the distributor and could not get it to budge without tapping it with a rubber mallet - the shaft was so full of crud it had basically seized itself to the block - obviously this motor was not taken care of.

Based on this, I pulled the valve covers off and found the expected sludge. Digging further, I pulled the intake and could not believe what I saw. It was not full of gooey sludge like I expected, rather it looked like someone had dumped a bag of charcoal briquets in it. Again, I can not believe this motor ran at all.

So, out it had to come...

[katwalk]

Needing to get the truck back on the road (it is my DD), I starting searching for an affordable replacement. I ran across a lady who was having an estate sale to get rid of a bunch of stuff her dad had accumulated. It turned out he worked for GM for 30 years and had an unused GM crate motor sitting in his workshop still wrapped in plastic and in the crate. She gave it to me for a great deal, so hopefully by the end of this upcoming weekend I will have it back on the road running better than ever with a new distributor, carb, water pump, etc).

Wish me luck - Farrell

[68 P.O.S.]

Damn, that escalated quickly lol

[Ol Blue K20]

That motor looked nasty inside..

[bry593]

Lucky guy finding that crate gem all wrapped up like a Christmas present. That old engine looks like most of them from 70's. The oil cooks on the bottom of the intake manifold at the exhaust crossover passage. It then falls into the valley. The sludge is due to the high amount of waxes used in oil back in the old days. Penz-Oil and Quaker State seemed to be the worst.

Be aware, your new engine may not run either for the following reasons:
1. Probably need a new fuel filter
2. Your quadrajet could be draining the bowl into the cylinders after shut down. This causes a flooding issue. Simply hold the throttle to the floor and crank until it fires up.
3. I hope you didn't buy an $80 Chinese distributor. These often fail right out of the box. Typical issue is poorly crimped electrical connections. I prefer to use an old GM HEI from a swap meet rather than shiny new Chinese garbage.

[gmc684x4]

Nice find new engine on a deal

I have cleaned up the goo out of old 70s engines and drove fine after
I did not realize part of it was due to wax content in the oil

[tim_mc]

Wow, glad to see you found a good crate motor nearby for cheap. I also agree with using a GM HEI. Don't forget to break in the fresh cam properly!

[notsolo]

Like Tim mc said, break in cam....are you going to pressure prime ? or spin the oil pump with the dist out? ....zinc additive?

[lutronjim]

The old one ran because it's a Chevy V8 - unbelievable have these things kept/keep going.

[katwalk]

Originally Posted by notsolo

Like Tim mc said, break in cam....are you going to pressure prime ? or spin the oil pump with the dist out? ....zinc additive?

I will spin the oil pump with the dist out and yes, will be using a ZDDP additive.

Thanks