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73-87 Chevy _ GMC Trucks => Fuel Systems and Drivability => Topic started by: Doppleganger on May 11, 2019, 10:46:39 AM

Title: Need someone who knows carbs in the SE MI / NW OH area
Post by: Doppleganger on May 11, 2019, 10:46:39 AM
This 85 K20 I have was bought from the original owner. His son was an idiot x100 and screwed up everything he touched. One of the areas is he put a new aftermarket distributor in.....was at 22 degrees when it arrived (probably because thats where junior dropped it in the hole at). He also pulled the beloved Quadrajet and replaced it with a Holly that was so far out of adjustment that even -I- got it closer. And also in doing so, he ripped off every one of the vac lines - there might be 1-2 still on it.

Truck acts like a Jag now....runs great - when it runs. Bogs like its going to stall under acceleration....and I cant describe what it sounds like when it starts cold.....groans like its a dead battery then vroom! I suspect that the cerebralplegic may have messed with a timing chain too....if so, I know its wrong.

Anyways.....its been 20+ yrs since my last SBC so I am admittedly beyond rusty. Local shops want their mortgages paid to 'try' - but since there's no OBD port they'd have to use Google to find the door handle.

We're staying with my 90+ yr old mother in law as my father in law just passed. We're on the north side of Toledo (about 8 blocks from the MI line). If there's anyone here who knows these things and are within striking distance, of course its a paying gig.

I've got bigger plans for this truck but it needs to function in the meantime.

TIA
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: Irish_Alley on May 11, 2019, 04:51:20 PM
lets start with the timing

http://forum.73-87chevytrucks.com/smforum/index.php?topic=32085.0

if it was mine i normally run about 16 of timing and have the vacuum advance attached to manifold vacuum.
the holly if i remember correctly on mine i had to turn both screws all the way in then back them out 1 or two turns then play around with that. i would google the carb number and try to find something from holly online
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: Doppleganger on May 12, 2019, 12:14:06 PM
Thanks much for the link - will look over this today.

I've worked on and restored older Euro cars for the last 20 yrs. Get alot of them that a shade tree changed his own timing belt then it wouldn't run right or even start. I'd ask them if they aligned the marks on the belt or distributor and would typically get the 'what marks?'.....thus my question was answered. This truck reminds me of that. Would like to collect a water pump and pull everything off the front (timing chain - have a new one already) and the distributor out, then find TDC and start over. I hesitate only because if it goes sideways and I cant get it started again, where it sits would be a real feat to get it out.....think Springer cutting the 600lb guy out of his bedroom.

The wiring is about as bad - only the oil pressure and speedo work - everything else doesn't - this after junior couldn't fix a broken ignition lock so opted to swap a whole 'nuther JY column in. At this point I couldn't either but am not shy to say so and let someone who knows what they're doing have at it. I have a whole new rebuilt column when the gut-it all day comes.
 
Thanks again for the link.....will begin cramming for the test tonight.
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: JohnnyPopper on May 13, 2019, 03:12:50 PM
And You're a wordsmith to boot! cerebralplegic Hilarious!

Your description of 'dead then vroom' - is that when it's warm or cold? He might have taken out the T-stat.

Operating temperature is a good thing, see if it's a factor.

Somehow I doubt the brain-dead one would have the wherewith-all to go into the timing chain, which raised another question: how many miles are on the motor?

If it has high mileage it would justify changing the timing belt.
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: Doppleganger on May 13, 2019, 03:30:32 PM
Yes....cerebralplegics.....paralyzed from the neck up. They show their club meetings daily on C-Span. The types that when they succeed in whatever they're doing, you give them a high five...in the face...with a chair. If my diagnostic skills at these SBCs matched my cynicism, I'd have a blog.  ;D

Motor has about 100k even. Starts HARD when cold - it literally sounds like the battery is dead. Once it warms, starts fairly normal. Only way I will/can drive it is to start it and let it run for 20-30 minutes, and even then it will sometimes stumble on acceleration. The few that have heard it start cold all thought it was far too advanced. Dunno. IIRC the vac advance line is missing...as is every other vac line. I have a fresh Q-Jet that was redone by Mountainman in AR - thought about putting it back on, but figuring more I'll peddle it to go towards the TBI I'd prefer in the long run. The Holly 650 thats came on it was new - might be 500 miles on it by now - that will go too.

Being everything on it is original (door seals, etc) everything needs replaced. The wiring is a disaster. At one time there was a 5th wheel in the bed and what was left of the towing wiring is a ball of tape hanging between the cab and the bed. But thats not an issue at the moment. Just kind of want to do a get-by on its runability so I can use it and enjoy it this summer before the big tear down. It has no heat (Einstein bypassed the heater too), as the climate control system was a dealer added aftermarket setup - I have a new Vintage Air for it once everything else is done, but it looks like the original factory heater core/blower is still in the dash unused. ?!

Otherwise the truck is stupid clean and rust free. Has issues (what 34 yr old vehicle doesn't?) but is a great starting point.



Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: JohnnyPopper on May 14, 2019, 01:50:55 PM
You do go on about the 'honorable gentlemen' from the States of...


I'll bet the brainiac took out the thermostat.

Next time you start it, look inside the radiator to see if the water is circulating.

If it is, you need one.

What keeps you from hooking up the VAC advance?

A S.B.C. at O.T. is a fine thing!
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: bd on May 14, 2019, 08:37:58 PM
I don't see a missing t-stat as being a cause of labored cranking while the engine is cold.  Use an incandescent test light or an ammeter to check for parasitic draws on the battery with all appliances and lights, etc switched off.  Perform battery load and cranking circuit voltage and draw tests while the engine is cold (when the labored cranking symptoms normally occur).  With the engine at operating temperature, check the timing using a proper light.  If you suspect a valve timing error, it is easy enough to evaluate chain wear.
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: JohnnyPopper on May 15, 2019, 02:38:59 PM
Hi BD, I wasn't addressing the hard starting, just the other symptoms of poor acceleration. I think that is heat related if he has to idle for 20-30 mins to drive it.

Sounds like the timing might be a factor, but if it's advanced that far that it fights being turned over, and without any mechanical advance at that point, wouldn't he have severe detonation?

Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: bd on May 15, 2019, 04:09:14 PM
The idea I'm trying to get across is that a methodical approach and some basic tests should benefit the diagnoses.  Verify that there isn't a simple battery/starter/cable/connection problem before walking too far afield.
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: JohnnyPopper on May 15, 2019, 04:19:46 PM
Agreed, the starter is his first point of pain.
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: Doppleganger on May 19, 2019, 10:13:14 PM
Sorry - been on the road so couldn't respond sooner.

Thanks fellas for the responses.

Starter is a new HD Bosch unit. Truck had an AZ sweatshop rebuild thing on it and it sounded stripped. I took it somewhere to be done and it was there they asked me why it was timed so far out. Fella there said he dialed it back to 8 (from 22 - no idea how he read it that high). I was talking to an ASA mechanic last Friday and he thinks the hard start is because its too far advanced. Dunno.

One thing I have noticed is that if I'm going down the street at say 40-45mph and accelerate, it sounds like its almost backfiring. From a stop light I have to REALLLY ease into the pedal or it stumbles.

I watched a few vids so will tackle this.....want to change the water pump and timing chain also (they are both original, circa 1985), and figured I'd pull the distributor and check it for timing then. Getting rid of an 18 month resto this week, then getting the next and last one into paint.....once thats done, then if I find a way to screw up a bowling ball and it goes sideways, the truck is not blocking anything in and can sit until I figure it out or get someone to make a house call. I have a new t-stat to install when I do the water pump anyways.

I'm going to try to get a vid/recording of this thing starting cold.....then find a way to upload it.
 
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: blazer74 on May 20, 2019, 03:42:29 PM
You say easing into the throttle or it will stumble from a dead stop, very well could be a worn cam lobe causing your issues.
Common problem.
If all else fails.
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: Doppleganger on May 23, 2019, 11:59:10 AM
Everything on it is original....water pump, timing chain.....all of it. 34yrs and 100k. How hard or $$$ is it to swap a cam in?

As soon as the re-arranging of the deck chairs here are done, I'm going to try and time it. If that doesn't fix it, I'll have to fast track the '99 5.7 and 4L80e here. Didn't really have the funds to dive into the shallow end on that part yet, but going to have to do something.

Wish I knew these like I do the old Euro/4-N stuff. I follow the general practice, but as with anything else, there are those little 'tricks' or nuances to doing it right the first time that I just dont know. One of my best friends was a master tech of 40 yrs - he would have been my secret weapon in doing all this and showing me how.....he up and died unexpectedly, so I'm on my own.
Title: Video of Hard Start
Post by: Doppleganger on May 24, 2019, 12:34:08 PM
Maybe this will tell what ails it. Its fugly, I know. Whats more is that once its warm, its starts right up no problem.

https://www.youtube.com/watch?v=32tC50cZ2EU&feature=youtu.be (https://www.youtube.com/watch?v=32tC50cZ2EU&feature=youtu.be)

Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: Doppleganger on May 27, 2019, 08:56:51 PM
If I cant find a knowledgeable shop to go through this, the truck will officially be for sale. I need a reliable truck and this one isn't it. I thought it was something minor but must be worse than I thought.

Thanks anyways fellas.
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: 1967KaiserM715 on May 28, 2019, 05:18:37 AM
You might need to shim starter, once the engine is warm/hot, thermal expansion pushes the starter away from the flywheel, bet cold engines have it closer, possible it is close enough to almost jam.

I would also check voltage at starter when cranking, sometimes I even just run another fresh battery and cord to starter to see if it is possible you have a weak battery.

Holleys sometimes have issues with powervalves, they leak, they don't work. A stumble that is solved by slowly easing into the throttle sounds like not enough fuel, and actually another possibility for the slow cold start-leaking fuel from the nozzles of the carburetor after shut down. Less likely then the above mentioned starter issues, but still worth mentioning.

Sent from my SM-S920L using Tapatalk

Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: JohnnyPopper on May 29, 2019, 05:28:37 PM
1967KaiserM715 makes the most compelling case, especially after the heat factor comes into play.

I have seen starters shimmed over the years, can't hurt to try. 
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: Doppleganger on May 30, 2019, 04:19:08 PM
Unplugged the distributor today and it turned over more quiet, fast and smooth than anytime I've ever had it.

That timing?
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: blazer74 on May 30, 2019, 05:47:24 PM
I would say so.
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: Irish_Alley on May 30, 2019, 09:30:15 PM
did you ever set the timing with a timing light?
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: Doppleganger on May 30, 2019, 10:44:48 PM
When the starter went tits up, I had a shop put it in. Guy there (30+yr ASA mech) said he timed it with the light and dialed it back to 10 deg adv (from 22). Supposed to be dry tomorrow - I think I have it close to TDC - have a tool showing up via USPS tomorrow to confirm its right on. At first glance, the distributor looks to be out - like clockwise an inch too far. I want to pull it out and start over - make sure its on. I have a light will dial it in myself afterwards.

I took the cap and rotor out today - they're basically brand new. I also pulled the plugs and I think (no joke) they may be original.....100k. Gaps were all over the place .020 diff between some. Got new ones in. Would also like to get rid of the Cali emissions that are on it - anyone know the thread size of the pipes that go into the exhaust mani? Will need a plug.
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: Doppleganger on May 31, 2019, 04:58:18 PM
Got everything timed today - at around 11-12 advanced. Runs good but still starts hard. For shts and giggles I took the battery out (<year old Interstate) to have it checked under load.....it failed. 1-2 bad cells. Maybe that was it? Dunno yet. 
Title: Re: Need someone who knows carbs in the SE MI / NW OH area
Post by: haroldwca on July 08, 2019, 09:46:01 PM
Would also like to get rid of the Cali emissions that are on it - anyone know the thread size of the pipes that go into the exhaust mani? Will need a plug.

I cut the pipe with a hacksaw flush with the surface of the threaded connector in the manifold.  Then I sealed the pipe with JB Weld.  Been in there for three years.  No sign of a leak or burn-through.