What have I done...

[howlinwolf]

Hey, newbie here, and new to this engine. I purchased a 1996 gmc k3500 with 220k miles. seems mostly ok.
things ive noticed wrong with it


slightly hard to start after sitting
stumble/die at times
gauge cluster is a mess (no tach, voltage gauge or check engine light)


other than that and the codes, it seems alright.


codes are
p0113 iac high input
p0216 injector/injection timing control circuit
p0251 injection pump fuel metering control "a"
p1810
p1860
p1870


but i like to learn and dont mind time behind the wrench

[Robyn]

Hello and welcome to TDP

Clear all the codes.

MAKE SURE THE BATTERY CONNECTIONS AND VOLTAGE TO THE MAIN BUS ARE 14 VOLTS OPERATING.

See what codes come back.

[howlinwolf]

Ill start with that. Thanks! I noticed its locked out overdrive, but that goes with the 1800 codes

[a5150nut]

Also might check and clean all your ground connections. On my 94 first thing I did was use spay cleaner on weather pac connectors and add dielectric grease to them. Never had an electrical problem for all the time I owned it 96/2013

[howlinwolf]

Cracked the crossover tube the other day, while making the repair, noticed a harness rubbing on the front driveshaft.

Repaired the broken wire and tied it out of the way.


Only code now is a p0216

[howlinwolf]

On the p0216 code, I've replaced the stepper motor.

Still here and hard to start.

The timing is showing a requested 8.6? But only getting 2.6 to 4 4 or so

[DmaxMaverick]

The IP is probably indexed out of range. Loosen, rotate, tighten. A little at a time. Timing can only be PCM adjusted within a narrow range.

[howlinwolf]

I could scream. The tensioner socket is broken. I can't drop the belt to pull the a/c and reach the pump bolts. But it looks as if the pump has been replaced.

More tomorrow I guess

[DmaxMaverick]

You can use a socket to rotate the tensioner by the pulley bolt.

[howlinwolf]

I have loosened the pump, but the housing wont turn

[DmaxMaverick]

It's fairly rigid if you don't loosen the injector lines at the other end. It is recommended, but not specifically necessary if only moving a couple degrees. There's also (should be) a gasket between the IP flange and timing cover that can be sticky.

[howlinwolf]

I figured out the pump movement part. Now I seem to have a fuel leak. It's near the front. Injector lines are tight.

My tractor guy, based off my explanation thinks its an internal weep or o ring failed on a plug

[howlinwolf]

housing cracked. new pump. ran fantastic for a few days. started her up, made it to the end of the block and it sounded like it ran out of fuel (its not. tank is full, filled 5 miles before home, and fuel guage works properly.) lift pump does need replaced (5 psi) but is moving fuel, rebled filter and lines. not getting fuel at injectors. Double checked fuel cutoff solenoid for operation, and fuel at that point, all good. unplugged optical sensor, still no fuel at injectors. at this point, my frustrations won and I went in for the night. sorry to the neighbor whos house its parked in front of.

[DmaxMaverick]

Unless you have another reason to replace the lift pump, 5 PSI is fine. Check it again at idle, when you can. 4 PSI+ is all that's needed. A failed lift pump may fail to start, but shouldn't cause a stall. The IP has an internal transfer pump, and will continue to flow fuel if the LP fails (power may suffer, but it will run).

Maybe revisit the PMD and/or harness. Check fuses. It sounds more electric/electronic than mechanical.

[DieselDavy]

Any progress on your issue Mr. Wolf?

[howlinwolf]

Yessir. Injection pump. The nut on the end of the shaft walked off. So the timing gear and drive piece on the pump spin, but the shaft does not.

Anyone have a used pump for sale?

[More Power]

Yessir. Injection pump. The nut on the end of the shaft walked off. So the timing gear and drive piece on the pump spin, but the shaft does not.

Anyone have a used pump for sale?

Might be worth checking the slack in the timing chain. Excessive slack can cause a whipping action in the timing stack, which introduces higher than designed limits in torque impulses that ultimately work against the injection pump drive gear... which can stress the connection between the IP shaft and the sprocket to a point of shearing the pin and losing time.

Check chain wear/slack by removing the oil fill tube, then rock the engine back/forth while observing the IP sprocket and the engine's crankshaft damper. Anything at/above about 4 degrees total crank rotation before the IP gear moves requires a new timing set. For info's sake, new chain timing sets produce about 2-3 degrees slack.

Jim

[howlinwolf]

Awesome. I'll start there.

Still need another pump

[howlinwolf]

I'm.... At a loss. Installed new pump. No fire. Thought... Timing gear jumped maybe?

It seems in time. (Marks line up. Pulled upper cover and water pump. )

[howlinwolf]

2 new batteries and it's trying to hit on one cylinder, giving a bit of a smoke show

[Yukon6.2]

Plug in the block heater
loosen the injector lines,

crank till you see fuel coming out,
tighten the lines.
if you remove the glowplugs it will crank easyer,and you don't have to loosen the lines on the injectors

[DmaxMaverick]

....if you remove the glowplugs it will crank easyer,and you don't have to loosen the lines on the injectors

This. It will be the quickest method to starting and completely purging. Crank until fuel mist is coming from each hole. You don't have to do the 6-8 cylinders if you can't reach them. By the time the rest are good, they will be, too.

[howlinwolf]

Most of the accessories are still off the engine, but she starts! Noticed no oil pressure, not sure if that's because so much is disconnected or what. I'll reassemble and check again.

Ended up with new batteries and a new starter

[DmaxMaverick]

That's great that it runs. Not so much with the oil pressure. Get that figured out before anything else. It's probably nothing but a sensor or wire, but if it isn't, it won't end well.

[howlinwolf]

It was fine when it died. Hoping its a ground issue or wiring. Like you said

[Robyn]

You can get a mechanical gauge screwed into the block easily enough.

Do that and see if you have oil pressure......
Once you know that pressure is OK THEN SORT OUT THE GAUGE/ELECTRICAL ISSUE....

[howlinwolf]

When you let a loose nut behind the keyboard...

I broke the sensor. Replaced with a new one.

Engine reassembled. Runs rough, low power,

[Yukon6.2]

Is there smoke when it's running?
If so what color is the smoke?
My guess is a big air leak in the fuel system

[howlinwolf]

Once it warmed up, not that I could tell. It was dark though

[howlinwolf]

Not seeing much smoke.

Also put clear line on injector return to pump and the line is clear of bubbles.

[howlinwolf]

Changed both rubber lines at the back of the motor, installed the new lift pump I've had sitting around, then finally found the leak coming from the heater part of the ffm.

How low of a temp can you run without a fuel heater?

[DmaxMaverick]

If your fuel is always winterized or treated for whatever temperature it will see, then you don't need a heater. The filter heater is intended for those times on the balance, to allow for a slight edge past that. It's a nice-to-have, but certainly not a requirement if you don't exceed the limitations of the fuel. Keep in mind, #2 will start to wax before it actually freezes, so a comfort margin is in your favor.

[howlinwolf]

We are running and no smoke after warming up. Still messing with timing though. Any input?