Cold start trouble

[simon]

My recently bought 95 chevy 2500 4x4 st trans 6.5 td truck has no trottle control after a -5 c and colder start up. It fires up fine on all eight but only at a very low idle and smokes grey like there is no tomorrow. it bucks along like it is just about to quit for sometimes up to 10 min till it kicks in and runs just fine . check engine light stays on most of the time.

I changed the electr foot control with no luck, then had it scanned and the scanner said faulty ECM, so i put a new one in, still the same trouble.
had it scanned again. no code found. but check engine light is still on.

I maintained this truck myself for a couple of years before i bought it and replaced the injectionpump 2 years ago and the injectors,plugs and turbo a year ago. the guy put about 35000 km on it afterwards.

rings a bell anybody??

[Robyn]

First off.
Welcome to TDP

With the SES light on there almost has to be codes setting.
My first call would be the coolant temp sensor but there has to be codes if the light is on.
We need to get some info on what the codes are????
Could be grounding issues.

Check all the grounds at the rear right corner of the intake manifold to make sure they are good to go.
Also check the plug down at the toe board on the right side where the harness runs through the firewall to make sure its not damaged or any wires pulled loose by the passenger foot area.

Make sure all battery cable grounds are good too at the engine and at both batteries.

With an ok condition when its warm it is an odd one for sure.
Have you tried a different PMD??

[Dvldog8793]

Howdy
See the similar post by Mark Rinker "cold start up question"
L8r
Conley

[simon]

Thanks for the welcome.

There are defenitly no codes set. ses light comes on and off almost constantly
As all these abriviatons drive me up the wall : what is a PMD? and where is it located?
Could it be a lack of fuel ,or the shutoff solenoid stuck in almost closed position. If that would be the case then wy the exsesive smoking, wich would point to a lot of unburned fuel.

If the footcontrol would be working, then a lack of fuel would kill the engine as soon as one tries to trottle up right?

There is one more thing i forgot to mention that might be unrelated, that is as soon as the i start the engine the radio switches rapidly between the clock, the tapedeck and radio again and keeps doing this till the engine finely runs good.
I got quite a bit of experience with the older 6.2 as i have 2 of them but the 6.5 with the electric inj pump is another can of worms.

By the way i checked the wiring all over and can find nothing wrong.
What the heck is wrong with this mocheen ??

[Dvldog8793]

Howdy
After hearing about the radio, SES light and electric throttle, I vote for grounding issues. sounds like Robyn was on to something. Double check and clean all the things she listed. The PMD is mounted on the fuel pump and is the transitorized electronic driver for the electric pump Since your vehicle seems to have multiple electric issues the only thing that really ties them all together( that I can think of) is a ground problem. My problem is solved if I plug the truck in, which I do anytime it's below 20*F, have you tried this?
L8r
Conley

[Robyn]

With all that other stuff whacko its got to be a grounding issue.
Start checking at the batteries and go from there. The side terminal battery cables are notorious for corosion where you cant see it.

The ground cables at the engine ends are another place.
The grounds at the rear of the engine on the right rear corner is another place to look.

If you have a bad ground on the right hand battery and the other side works it will start and run but things will get real hinky.
The alternator ties into the left hand battery then the crossover cable ties the two together.

Check all this stuff and let us know.

Good luck
Robyn

[simon]

Thanks for the reply.

If it is a ground problem wy would the problem disapear after initial warmup?
A bad ground is a bad ground.

The problem happens only after sitting overnight and only when the temp is below 0 celsius, plugging the block heater in makes no dif.
during the day it starts and runs just fine and dont even requare use of the glowers, just turn the key and it runs.

[hayesash]

I was having similiar problems. Low idle at first start up in the morning coughing sputtering. Not all the time. Very intermittent. It all started this fall when the mornings were cool. Changed glow plugs.This helped but still not right. Checked and cleaned all grounds , the one on the frame was the worst. Seemed to make a bit better but not perfect. In our -28 C It barely turned over but did start and it was plugged in. Since I recently changed batteries I knew it was time for a starter. The pos cable on the solenoid was corroded quite badly. Cleaned it up hooked it up and turned the key. Couldn,t beleive how quick it started. The next morning -20C not plugged in and it started better than it has in months!
Not sure what exactly was the problem. Maybe a combination of weak starter ,bad grounds and weak glow plugs. Very frustrating! 2 weeks ago I was ready to give it away Now I like it again. Hope this helps.

Pat