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Old 09-30-2018, 08:31 PM   #1
76C10Stepside
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What Would YOU Do?

I apologize in advance for the long post. I have a dilemma, and am hoping to get just the right advice on how to proceed.

Just replaced the right fuel injector on my 1989 S10 4.3 TBI auto trans. Note that this is an early 4.3, and a lot of things are different from the later models (read: before improvements made).

History: Had previously rebuilt the TBI. After rebuild, one injector failed and filled the crankcase with gas (discovered after running engine for about 2 minutes). Replaced the bad injector and changed the oil and filter. Did not drive the truck much after that due to electrical issues. Recently replaced the valve stem seals, which either got cooked or failed "naturally". Have been driving it regularly since. It runs pretty well, plenty of power, but intermittently idles too fast and rough. It has been using some oil, but no apparent leak or smoke (new seals cured that).

Decided it was time to replace that other injector.

Chiltons manual said for trucks equipped with the Model 220 TBI, just have to let the vehicle sit awhile (has sat for 2 days) to relieve fuel pressure. But, when I removed the top of the cluster, gas started running out. Not high pressure, but a regular stream (more than a dribble, less than a spray).

Used rags and paper towels to soak up the gas and plugged the hole, then proceeded to replace the injector. Had to do it three times to get the large o-ring to seat correctly, so there was more leaking than expected.
Some gas leaked into the throttle body, but most of it seemed to get soaked up or drip onto the intake manifold.

When I try to start the engine, it make loud noises like starter gear grinding, and stops trying immediately (like it's jamming). Only on one try did the engine seem to turn over at all. I'm not 100% certain that this is actually what is happening, tho. The starter is "near new" and has never done this before. Also found that it was low on oil, so added some.

Gave up after 15-20 tries and rigged the throttle to wide-open position. Do you think the gas in crankcase will evaporate, or am I wasting my time trying? Did I just have bad luck on the starter, or could this have something to do with the gas in crankcase? The last time, over a gallon of gas leaked into the crankcase before I was able to stop it, and it still started right up.

What would YOU do at this point?
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Old 10-01-2018, 12:59 AM   #2
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Re: What Would YOU Do?

Now i'm not an expert but If It was mine i would remove all the spark plugs and turn the engine over by hand (with a wrench) if it spins free, I would bump the starter and see how it acts. Trying to figure out if the starter is malfunctioning or if its in the motor. I would expect the gas to run down past the rings easily enough but......if you care about the motor which i'm sure you do once that issue is resolved I would change the oil to get the gas out of there. Gas in the oil shouldn't make it act like that. Just ruin the viscosity and protection the oil gives.
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Old 10-01-2018, 07:08 AM   #3
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Re: What Would YOU Do?

Low voltage to the starter is what it sounds like. Same symptom as a worn starter requiring more than good battery can give. I assume your battery is good.
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Old 10-01-2018, 04:35 PM   #4
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Re: What Would YOU Do?

Quote:
Originally Posted by Sim6 View Post
Now i'm not an expert but If It was mine i would remove all the spark plugs and turn the engine over by hand (with a wrench) if it spins free, I would bump the starter and see how it acts. Trying to figure out if the starter is malfunctioning or if its in the motor. I would expect the gas to run down past the rings easily enough but......if you care about the motor which i'm sure you do once that issue is resolved I would change the oil to get the gas out of there. Gas in the oil shouldn't make it act like that. Just ruin the viscosity and protection the oil gives.
That seems like a good plan. Removing the spark plugs and turning the engine on this truck is a real chore, and my back is acting up again. Will try bumping the starter again (did not work yesterday), then try turning the engine with the plugs in (they are really hard to remove).

The 29 year old engine only has 53k on it, so I'd like to keep it around for a few more years, LOL.
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Old 10-01-2018, 08:39 PM   #5
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Re: What Would YOU Do?

If you cant get the plugs out...turn the engine by hand...backwards..

It sounds like the cylinders filled with raw gas and have hydraulic locked up....

If you have a wrecking yard close by, try buying a second hand TBI unit and installing it...so many times I have witnessed rebuilt units fail and fill engines with gas...

Of course you will need to change the oil again and filter...

Good luck.

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Old 10-01-2018, 10:45 PM   #6
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Re: What Would YOU Do?

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Originally Posted by AussieinNC View Post
If you cant get the plugs out...turn the engine by hand...backwards..

It sounds like the cylinders filled with raw gas and have hydraulic locked up....

If you have a wrecking yard close by, try buying a second hand TBI unit and installing it...so many times I have witnessed rebuilt units fail and fill engines with gas...

Of course you will need to change the oil again and filter...

Good luck.

Thanks for the suggestions. I see you are in NC where all the flooding is going on. I'd never even heard of hydrolock before. Will try turning engine backwards tomorrow!

Am wondering why the system is not relieving fuel pressure and how to fix that. Why didn't GM put a relief valve on the fuel rail that I could stick a hose on??? Cannot believe how much harder this truck is to work on than my old C10...
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Old 10-02-2018, 05:22 PM   #7
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Re: What Would YOU Do?

Just pulled all the plugs. Only one of them was wet. Tried pumping gas out of this and one other cylinder, but nothing came out. It's a 90 degree engine, and the plugs are horizontal. I inserted plastic vacuum hose and did my best to angle it down, but it probably did not get very close to the bottom wall of the cylinder, so if there was still any gas in any of the chambers, it's probably too low to reach.

The engine rotates "freely". Not easily, but can turn it both directions with a short breaker bar, and no noises, so the rings are not stuck. The engine didn't rotate when I tried to start it, so no way it could be seized.

I have motor oil, but no oil filter. It's over 12 miles to the nearest civilization, and farther to the nearest auto parts store. I can't change the oil filter and don't want to waste 5 quarts of oil and risk the drive to town.

Since the engine has not turned hardly at all (only rotated it back and forth about 10 degrees a couple of times), I'm not sure if any gas can have worked its way into the oil filter via gravity. The oil filter hangs upside down, so I suspect this is possible.

So, I have to decide what to do from here. I could let it air out for another day, but pretty sure all the gas that was in the chambers has either leaked down into the sump or vaporized by now (there is no obvious gas odor). From past experience, the gas in the oil probably is not going to evaporate.

I have some important things to do, so would rather not wait for a new oil filter to arrive in the mail (probably faster than finding a ride into town).

What would you do next in this situation?
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Old 10-02-2018, 10:26 PM   #8
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Re: What Would YOU Do?

Found a Fram PH3535 filter (discontinued) that's the right size. Drained the oil then tried unsuccessfully to remove the old oil filter off. Oil filters on this truck and my C10 have always managed to weld themselves to the engine despite oiling the seal. Tried all the tools I could scrounge up, including a useless end cap filter wrench (just spins), a chain tool (squashed the cartridge but could not turn it), and a screwdriver hammered through the cartridge (which usually works), but have nothing to use as a breaker bar/tube to get leverage on it (half my tools are in storage). Also could not find the fuel pump relay in engine bay or inside fuse panel (was planning to crank engine to expel any fuel still remaining in the combustion chambers). Will take another shot at it tomorrow.
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Old 10-03-2018, 06:45 AM   #9
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Re: What Would YOU Do?

If it happens to all of your vehicles, it sounds like you are tightening your filters too tight.

I would recommend a wix 51036(long filter) or a wix 57040(short filter) or a wix .

The fuel pump relay mounted to the firewall. If you have A/C, the fuel pump relay is the one closest to the right(passenger side)

I would not unplug the relay. It has a redundant circuit that will supply power to the fuel pump once the engine has oil pressure(even with the relay removed). I would pull the fuel pump fuse, or unplug the fuel pump itself(3 wire connector at the top of the frame rail at the front of the bed), or use a test lead to supply power to the S terminal at the starter. I would do the last method, as that will also leave the ignition system disabled.
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Old 10-03-2018, 08:47 PM   #10
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Re: What Would YOU Do?

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Originally Posted by 95 S_Trucker View Post
If it happens to all of your vehicles, it sounds like you are tightening your filters too tight.

I would recommend a wix 51036(long filter) or a wix 57040(short filter) or a wix .

The fuel pump relay mounted to the firewall. If you have A/C, the fuel pump relay is the one closest to the right(passenger side)

I would not unplug the relay. It has a redundant circuit that will supply power to the fuel pump once the engine has oil pressure(even with the relay removed). I would pull the fuel pump fuse, or unplug the fuel pump itself(3 wire connector at the top of the frame rail at the front of the bed), or use a test lead to supply power to the S terminal at the starter. I would do the last method, as that will also leave the ignition system disabled.
I always oil the seal and turn them 3/4 of a turn after contact as recommended. Of the many vehicles I've owned over the years with spin-on filters, only these two trucks have stuck this bad. I prefer the WIX filters too. This FRAM filter was just kicking around at just the right time.

Still have not been able get the old filter off. There is no room to work and all of my jacks are in storage. The filter body is very thin, and the filter is buried up in there. Even if I could chisel the can off, not sure I'd be able to get up there and put a drift on the metal plate. I saw a vid with 5 ways to get a filter off, and the only one I haven't tried is the "octopus". That gave me the idea of putting a couple of bolts through the end filter tool and the end of the canister. Was only able to get one bolt even part way in there. Just is no room to hammer anything, and the filter metal is super thin. I take it GM relocated the oil filter on later model to the fender well. Good idea. Wish mine was there.

Called a mobile mechanic that is going to try to stop by late in awhile. Maybe if we jack the truck up we'll be able to get at it.
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Old 10-03-2018, 10:22 PM   #11
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Re: What Would YOU Do?

The mobile mechanic (good guy) showed up with a really long screwdriver that was able to reach the base of the filter and turn it using a 2lb hammer. My longest screwdriver was too short and not sharp enough. Got the new filter on and oil in. Will pick up from here tomorrow.
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Old 10-06-2018, 05:24 PM   #12
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Re: What Would YOU Do?

Thanks to all who responded. It's fixed. Need this truck to get me through the winter. There are two other issues remaining that I'd like to address to keep this truck on the road.

1) There is a throbbing and some vibration (sounds like cooling fan blades?) when idling in gear (at both cold idle and warm idle 750 rpm), and at very low speed, e.g., when coming to a stop). It goes away once I reach 20 mpg or so, and engine runs great otherwise, and no noise.

I suspect torque converter is not happy (oil starved), possible blockage in transfering fluid to it. The trans is not low on fluid. Am hoping changing the trans fluid and filter will fix this (probably overdue). I believe it's either a 4L60 or 4L80 (automatic with overdrive). It's been a good trans so far, and truck only has 52k actual miles on it.

2) The A/C compressor was kicking on/off constantly, and there was a drag on the engine when engaged. I unplugged it a couple of years ago, which stopped the behavior. But I know from past experience that it's only a matter of time before the clutch fails, then the bearing seizes and the serpentine belt burns up at an inconvenient time/place.

This truck is 29 years old and not worth cost to replace the entire A/C system.

Considering replacing the A/C compressor with either a reman unit, or an A/C delete idler pulley. Just replaced the serpentine belt, or would consider doing a total delete and going to the shorter belt (looks like you can do this on the 4.3?).

Reman A/C compressor: Lots of negative reviews saying it didn't work!

A/C Delete Idler Pulley: The ones at FLAPS look very cheap. Will it last?

Total Delete: Does the 4.3 engine permit going to a shorter non-A/C serpentine belt that bypassed the A/C compressor altogether? Looks like there is a non-A/C belt available.

Would did/would you do, and did it work? If not, what went wrong?
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Old 10-11-2018, 12:15 AM   #13
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Re: What Would YOU Do?

Sounds like your cycling pressure switch is cycling because of a low refrigerant charge. Have you put the gauges on it? Do you have any R12?
I drive an '89 4.3 S10 100 miles ever day & this has been the absolute most labor intensive vehicle I have ever owned! It had 99K miles on it when I got it home (Not running of course) & I've put 35K miles on it.
I've seen just about everthing an S10 can pull.
Oh & your trans should be a 700R4 like mine.
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Old 10-17-2018, 07:41 PM   #14
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Re: What Would YOU Do?

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Sounds like your cycling pressure switch is cycling because of a low refrigerant charge. Have you put the gauges on it? Do you have any R12?
I drive an '89 4.3 S10 100 miles ever day & this has been the absolute most labor intensive vehicle I have ever owned! It had 99K miles on it when I got it home (Not running of course) & I've put 35K miles on it.
I've seen just about everthing an S10 can pull.
Oh & your trans should be a 700R4 like mine.
Thanks for the tip on refrigerant charge. I was just going on the fact that it still blew cold air when it was still hooked up, lol.

The engine idles fast when the heat is on and when the humidity is high. So, today, I tested the leads to the MAP sensor. Got 5.09 volts on the white wire, so it's got good reference voltage. But when I checked for continuity to ground on the other two wires (green and red), I got strange resistance readings on my DVM. Not sure what to make of these, and did not even get around to testing the MAP sensor itself.

Green wire: With DVM set to 2000k ohm range, get 126, and at 200 omh range, get 499!

Red wire: With DVM set to 2000k ohm range, get 207, and at 200 omh range, get 1!

Note: This is a $5 Harbor Freight DVM, but it seems to be working (steady readings, and voltage is in expected range).

Any thoughts on the weird continuity readings?
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