6.2 idle adjustment and other problems

[buff_dog70]

How do you adjust the idle on a 6.2? Trying to fix stalling problem. Happens when foot comes of accelerator (sometimes) and turning (sometimes). Engine can be either hot or cold. Didn't happen for a while cooler weather, then I fueled up (28+ gallons). Problem became more freqent. Would like adjust idle up a little.

Seperate issue, I notice on cool mornings that "water in fuel" light comes on. Later in the afternoon, warmer not on. Could this be real water in the fuel. Is there a drain sump to get rid of this unwanted water?

Is normal on a 82 Jimmy diesel to not be able to start vehicle from neutral when while driving? The engine dies then I have to coast to a complete stop. Then put the shifter (automatic) into park to reset the ignition, then can I re-engage the starter.

 

[imiceman44]

How do you adjust the idle on a 6.2? Trying to fix stalling problem. Happens when foot comes of accelerator (sometimes) and turning (sometimes). Engine can be either hot or cold. Didn't happen for a while cooler weather, then I fueled up (28+ gallons). Problem became more freqent. Would like adjust idle up a little.

Seperate issue, I notice on cool mornings that "water in fuel" light comes on. Later in the afternoon, warmer not on. Could this be real water in the fuel. Is there a drain sump to get rid of this unwanted water?

Is normal on a 82 Jimmy diesel to not be able to start vehicle from neutral when while driving? The engine dies then I have to coast to a complete stop. Then put the shifter (automatic) into park to reset the ignition, then can I re-engage the starter.

On the 82 They didn't have a provision for removing the water, you can still do it but it's harder.
The shifter switch on the column can be adjusted so you can start it in neutral and park, it's probably just out of adjustment.
I don't remember much about the adjustments on the idle, I believe there should be an idle screw at the cable connection to the IP.

 

[MaxPF]

There is no idle adjustment per se on a a 6.2. There is a stop screw IIRC, but the idle itself is controlled by the governor. You're thinking of it like a carbed gas engine where it will stall if the idle drops too low or undershoots, but it doesn't work that way on a diesel. If you are stalling then you have other problems...

 

[rwright07]

the water in fuel light is also a signal that the fuel filter may need replacement, it will come on more and more frequently as the filter becomes clogged.

 

[buff_dog70]

Whats the IIRC

I will look into the neutral/park switch adjustment.

Whats the IIRC.

Will playing with the stop screw fix/hurt anything?

I will replace the water seperator and filter? Is this best or is there after market part that can drain water also? What is the harder method.

Anybody think the lift pump or the injector pump is going? How do you check the injectors themselves?

 

[MaxPF]

I will look into the neutral/park switch adjustment.

Whats the IIRC.

Will playing with the stop screw fix/hurt anything?

I will replace the water seperator and filter? Is this best or is there after market part that can drain water also? What is the harder method.

Anybody think the lift pump or the injector pump is going? How do you check the injectors themselves?

IIRC=If I Remember Correctly

 

[4x4_76]

Wasn't there a plastic retainer or something inside the pump on early models, that broke in time and clogged the fuel return on IP, therefore causing it to stall?

edit/ Yep, governor weight retaining ring. Take off the IP cover, and see if there is any plastic particles inside the pump. Remove stop solenoid and HPCA wires from cover, then unscrew three screws and lift off the cover.

 

[buff_dog70]

Can Manually fix idle

I figured out that by bending the metal tab (by the pre-engine heat up solenoid), I can "manually" fix the idle. I bent it a little and it did fix the problem, still stalling. I been thinking of removing my temp solenoid and mount some kinda of adjustable bolt, or clamping shims to the tab (instead of bending).
But I'm not sure if the idle changed much. How do I reliably monitor the idle speed. Don't want to keep bending/adjusting when I not sure how far or close I am to 650 rpm.
I noticed the engine most reliably stall/dies when I come off the throttle hard (let the pedal snap back). I wonder if the engine throttle assembly build up enough momentum when it hits the temp solenoid that it pushes it in too far (dropping the idle below 650 rpm, thus stalling the engine.)

Still can't figure out how to adjust the ignition switch while in neutral. Looked in the GM manual and still can't figure it out. Any help to cure the can't restart engine in neutral would be greatly appreciated.

 

[thedrip]

My engine was stalling under same conditions, particularily getting off the throttle quickly. Fuel filter and I was golden. Diesels do all kinds of weird things when they don't get fuel.

 

[buff_dog70]

Installed new fuel filter

I was on the way to work this morning, and I ran out of fuel. Guage showed 1/8 tank. Walked home got back up ride.

Returned with a new primary fuel filter, and 5 gallons of #2. Changed filter noticed rust on metal inside filter. Drained my gas can in tank. Guage now showed 1/2 tank. Drove away.

Filled up at gas station another 21 gallons.

The Jimmy has been working great since. Been trying to get to stall by hard throttle then let off hard; used to do the trick everytime, nothing, still thumping.

Thanks for the help, I still think the idle is too low. Looking to get an alternator with rpm signal so I can hook up a tach.