Fix One Thing, Another Goes Wrong!

[LBJ]

As I posted yesterday, I finally got the front brakes working OK. Got it State Inspected and relincensed for 2016.

But, ideally, you think you have all things working great, but fix one thing, and you might just cause something else to mess up. Which happened to me.

I text drove the truck several times yesterday and this morning, ran just great, accelerated, stopped, idled, everything ideal. On the way back from the courthouse where I got my new registration, I put 9 gallons of gas in and drove home, ran fine. Decided to fix a couple of things while I was in the mood the weather was nice here in TX.

Next on my list was the door hinge pins. They keep working out after 10 or 15 door openings/closings. I got my Dremel tool and cleaned off a piece of bare metal on the hinge swing arm right where the hinge pins are so the weld would be grounded properly. Made a couple of quick tack welds and the pins were in for good.

After doing a couple of other small things, I drove back to the Auto Zone to get credit for some brake items I didn't use or need. Wow, pulling out of the driveway, the engine died on the most minor acceleration. I figured the engine was cold again, restarted and drove on. Every time I tried to accelerate the engine would almost die. On the highway, I barely got to 55 MPH. Drove around town, just barely ran. But, as long as it just idled, she ran fine. Bought some gas cleaner at the Auto Zone and poured it in the tank thinking it might be some water in the gas I just bought. That didn't seem to help.

On the last stretch of road to my house off the highway, I pumped the gas pedal several times and then really put my foot in it. BANG, big backfire.

So, with the engine running near perfect early in the morning, to now barely running, I messed something up with the welding or got some bad gas. If the welding messed something up, like the electronic ignition, it seems it would have knocked it out completely. But the engine still starts and runs fine at idle.

Maybe by coincidence, the fuel filter has gotten clogged with the 9 gallons I pumped in. Maybe some old crud got knocked loose and into the fuel line.

Or, also by coincidence, maybe the fuel pump is going bad. I checked all the vacuum lines and the line between the frame and fuel pump from the gas tank - all in good shape. The line between the pun and chassis has failed/cracked in the past is one of the first things I check if the engine won't accelerate.

Other than these things, I am out of ideas. Any suggestions? Sorry for the long introductory comments.

[hatzie]

Check your spark plugs.
If it hasn't been driven in a long time the carb may not be happy and it's running rich.

[LBJ]

I'm going to replace the fuel pump first. I took a close look with the engine running and it was blowing out small bubbles of oil at the gasket location. All around the pump where it bolts to the block is wet oil as if it's been leaking a lot. So, it appears I have an ailing fuel pump or maybe one that's about to go totally bad. Guess it won't hurt to have a new F.P. at any rate. Cannot remember how long that one's been on. If that's not the problem, then on to other possibilities.

[hatzie]

Change your oil too to get rid of the extra gasoline in the crankcase from the leaking fuel pump diaphragm.

[LBJ]

Hatzie, that's an interesting point. Never thought of that. I did install the new fuel pump today. Drove it a few minutes while it was warming up. Ran like a spotty azz ape! Came back, put air in the tires to take a longer "victory" drive, got out on the road and wham, back to barely running. After warming up, barely hitting the gas pedal made it want to die, the engine just blanked out until I let off the pedal. Strangest thing.

I wonder if the gas in the oil would cause it to run erratically? I did check the plugs and they need changing, no doubt. Gaps were large and had a brown to grey buildup on the electrodes. Engine dieseled when I shut it off after driving while engine at operating temps. Just seemed to be running rich all the sudden. Choke seemed to be off when I looked in there, and I flipped the air filter cover upside down to get more cold air to the carb - ran worse. This is a really strange deal! I have a carb kit coming and will go ahead and clean the carb up since it couldn't hurt it any. But, unless i find some crap in inside thew carb, not sure it will make any difference in the engine running. I'm wondering if I got some water in the last fillup? That's the only thing I can imagine at this point.

[Front Range]

If it runs well when cold (rich) and then runs bad when warm that sounds like a lean condition. If it runs worse when you introduce more air, again that sounds lean.

[LBJ]

Front Range, sounds right. Something must be blocking either the accelerator pump or something else in the carb. It's running OK on the idle circuits, but when the pedal is depressed, the front butterfly valves open, making it leaner, and the accelerator pump is supposed to kick in the raw fuel to offset that. Apparently, that's not happening after it's warmed up.

[truckin 79]

Check the simple things first like the choke. I bet that is the problem your choke is not working properly. When you get truck up to operating temperature the primary choke butterfly should be standing straight up, if it is slightly closed engine will be running rich and want to die. Also if truck has not run in a while linkage could be rusty and need a little lube

[ironroad9c1]

if you have a qjet dont forget the filter in the carb right at the inlet. Its running lean Not rich, take the cap off your tank and see if it sucks air in, vent system might be plugged. .

[Front Range]

I can't remember if that carb has more than 1 position for the accelerator pump link adjustment. You could always try to shorten the stroke to confirm. Try a can of carb cleaner and flush the carb out while running the throttle by hand, check for leaks at the carb base gasket and vac lines - especially the vacuum advance line from the carb base to distributor. Check the PCV and make sure it isn't stuck. It sounds like a fueling issue but you need to make sure the ignition side is performing too = correct timing, good spark/coil/wires/plugs/rotor/cap.

Good fueling + good spark/timing = good running motor

Bad fueling or bad spark/timing = bad running motor

[LBJ]

Ironroad9c1, I think it may have had a non venting gas cap and a vacuum formed in the tank, especially since I just filled the tank up the other day. I was going to check that out, but the engine died and now won't even fire off or start. I will get someone over tomorrow to crank the engine while I see if she's getting spark to the plugs. I think I may have damaged the electronic ignition with that welding on the hinges since I failed to disconnect the battery. That's when the whole mess started.

First thing today, I installed both new fuel filters and drove it. It ran fine until it was running about 15 minutes. Then, the same old thing started up - touching the gas pedal almost killed the engine. After that, I blew out the gas line from the fuel pump to the tank and could hear it gurgling in there. Next, I taped off the gas fill port and put a hole big enough for the air compressor nozzle to go thru and pressurized the tank. Pumped out a gallon of gas into the coffee can in a second. No sign of water or any other contaminants in the gas. So, the lines aren't blocked. A friend told me about the gas cap possibly being non venting and I really think that was the main problem. It ran normal long enough to build up a vacuum, and then after being off for a few hours, the vacuum neutralized. If she starts in the morning, I guess it was just flooded when I tried it this afternoon and wouldn't start. If she won't start at all, then I guess the ignition is fried. This mess is really wearing me out! Not to mention costing more more more.

Frontrange, I did check to see if the accelerator pump was pumping, works great. I set the timing right on the factory spec two years ago and the distributor is not moving by hand. It starts and runs like a top on the first start of the day. You'd never know it has 85K miles on it by listening to her purr.

[LBJ]

Tried to start her this morning, won't fire at all. Guess the distributor gets some new parts. Ha. Checked fuses and they are OK. Voltage tested the wire on the firewall that supplies voltage to the distributor - 12 volts. I hate to crawl over the engine to get to the distributor. But, guess that's the way she goes.

[LBJ]

Sadly, changed out all the distributor ignition parts today - module, rotor, cap, coil unit, wires, and plugs. Still doesn't run, or even fire. When the truck stopped running yesterday, it just quit firing. I keep wondering if there is a fusible link under the hood somewhere, or in the ignition wiring, that blew, but the fuses under the dash are still good. I have 12 volts to the firewall junction block connection that supplies 12 volts to the distributor, so it's getting power. I'm going to buy a trouble shooting probe so I can check to see if individual wires are getting 12 volts with the ignition on. My old one isn't working. I am out of ideas.

[wilkin250r]

If it's not firing at all, a really simple diagnostic is Starting fluid. A little shot down the carb throat. If it fires and dies, it tells you that your engine is essentially ready to run, it's just not getting fuel, and your most immediate problem is somewhere in your carb or other fuel-delivery.

If it DOESN'T fire, it tells you there is something wrong with the engine itself, and to start checking the engine side of things (I usually start with spark and timing).

[LBJ]

Wilkin, I just bought a remote starter rig and a plug tester light. I am working by myself, so cannot monitor what's going on under the hood while in the driver's seat, so I needed a remote switch. I am pretty dang sure I am not getting a spark. Getting gas for sure as I worked the linkage while looking into the carb and saw the accelerator pump spraying fuel into the carb. And to boot, the distributor may have broke. I opened up the distributor to replace the cap and all that, then tested, then later opened it up once more to replace the condenser and the rotor was still in the same exact place. Now, that's a bit hard to believe that it stopped in the same place twice. I will test on Sat to see what's going on. I am worn out tonite.

[Front Range]

Hang in there bud, you'll get it.

[Zach079xxx]

I know exactly what you're going through. My dizzy got out of timing months ago ran like crap so I had a local shop time it. They somehow fried it, old wires so it was bound to happen so I got a MSD to replace it. Ran great for months then last week it is hesitant similar to when it was out of timing last time yet the dizzy is tight and cannot be turned. I also had the gas tank problem. I can't fill it up more than 3/4 or it runs like crap until I burn some out. I drilled a hole in the gas cap and it's ok BUT I still can't fill more than 3/4 sometimes even 1/2 tank. Curious as to why she's running crappy lately I'm gonna have it looked at. Timing is not my thing and I don't have the tools for it

[Gregski]

story of my life! what fuel filter are you using?

[LBJ]

Pulled the distributor and found this. Snapped clean in two. Might have happened when it back fired big time. Break looks new, but since it's been in a closed environment, hard to say. Kinda surprised to say the least. I can buy a brand new unit from the local auto-supply for $100. They'll have some in next week. It will have the cap rotor and all the guts too. All I need is my wires. I really want to get her back together and move on.

[hatzie]

Just say no to the $100 Chinese units. They are generally pretty crude pieces with poor electronics.
Get a used HEI distributor and rebuild it. You can mix and match hard parts from your unit. You'll end up with a far more reliable piece than a crude Chinese imitation.

[LBJ]

Hatzie, that's a good point. Never considered where the new ones came from.

[cadillac_al]

I'm one of the happy campers running the chinese stuff. I have 5 of these distributors with no failures yet. If it dies, how much are you out? At the most a tow bill.

http://www.skipwhiteperformance.com/...?Item=6500-GRY

I've never seen a dist break like that. It makes me wonder if the clearance is right at the intake manifold. I don't know if being too tight would do that or not.

[LBJ]

Caddy Al, Not sure how that broke. Unless, it was a flaw from manufacturing. Only took 39 years to break! Well, really not sure when it broke since that's the first time I've had it out. But, could be related to the huge backfire it had just a few days ago.

That Skip White distributor is cheap enough!

[hatzie]

The problem I've seen with the Chinese small cap HEI distributors is they use a cheaply constructed pickup coil and reluctor that doesn't provide a reliable signal to the equally cheesy module. These units can not use the OEM pickup coil, or module with the Chinese reluctor so you can't just install a decent Delphi Pickup coil and Module. Assuming you threw out your old distributor you get to find another re-buildable GM unit.

If the Skipwhite unit is completely compatible with the GM large cap HEI. Big IF meaining you can use standard AC-Delco Delphi Electronics and GM mechanical parts on the inside... it's still an expensive core with crude Chinese electronics.

I'm not going to lie. It will cost about the same or a little more to rebuild a GM HEI core.

Any GM large cap HEI from a smallblock Chevy V8 in a 1976-1980 GM car or light truck will work as a core. It should cost about $25-$35. They take about 1.5 hours to rework completely. Inspect the part to be sure the pivot pins for the mechanical advance weights aren't badly worn out before you accept it.

Test the vacuum can on the broken HEI. It's already setup for your engine so use it on your rebuild if it doesn't leak. Adjustable replacements are in the $10-$20 range.

Parts you will need;

• Sil-Glyde Grease. Probably $15-$20 now for a lifetime supply. You should have this stuff in the toolbox anyway. I use it on hose barbs and electrical terminals. It doesn't melt radiator hoses and keeps them from sticking to the barbs... It also keeps exposed terminal connectors, like the HEI coil to module plug, along with bayonet and wedge base bulbs and sockets from getting corroded.
• HEI Distributor gear shim kit. End-play should be @ 0.010-0.015. Timing will float 1° for every 0.013" of end-play so you want to get as close to 0.010" as possible without going less. Most distributor gears have excessive end play. One of the easiest repairs you can do is to shim them. The usual speed parts outfits have HEI gear shims for around $5-$10
• Real Delphi AC-Delco Professional Ignition Module. $20-$30
• Decent HEI coil to module wiring pigtail with capacitor. $10-$25 Google HEI Capacitor.
• Brass terminal cap and rotor. $25 or less. You may be able to re-use yours but this is as good a time as any to replace them.

You might need a coil but it's unlikely. Don't bother with "hot" coils. The recovery time and voltage on a real AC-Delco Professional grade coil are very good for street driving with no drama. Be sure the ground terminal makes contact with the laminated steel transformer core. If you have to sand off some paint... do it. AC Delco Professional coils are $35-$55

It's extremely unlikely you'll need a pickup coil. I've never replaced one. AC Delco Professional is $45 but again it's unlikely you will need one.

This is a pretty good writeup on how to do a whole rebuild.
http://www.rustpuppy.org/ignition2/Ignition%202b.htm

[hatzie]

For you folks that are missing the original large cap HEI Plug wire locking ring...
$4 from O'Rileys BWD WR1