1994 6.5 Burb Fuel and idle problems

[Hooptybass]

Im new to the forums and thanks for any help in advance:D:D
I just picked up a 94 6.5LT Burb 3/4 ton 4wd
The truck starts fine puffs some white smoke for a bit then cleans up. Idles fine UNTIL you either run down the drive and let your foot clear off the throttle and it idles back fast it develops a miss .. or you can blip the throttle and it will do it too... then it wont come outa the miss unless you shut the truck off and let it set for a few then start it back up .. but it ill do it all over if you do the above . but you can let it idle all day long and no miss ...
I was told when i bought it the pump was rebuilt and the mod was mounted on the firewall... thanks again Brian

[Robyn]

Welcome to TDP

Good to have you onboard.

Now about the issue at hand. Any codes ???

Some things to think about.

Fuel filter, lift pump, any air in the system ( install a clear hose on the IP return and watch for bubbles)

Could be a bad injector too.

Any strange noises at idle when it misses.

Let us know

Robyn

[Hooptybass]

Ok i did some digging tonight and here what i did and what i came up with . I replace the fuel filter ... then started it back up ..and pulled 3 codes outa it
#36 Injection Pulse Width error (Reponse time too Long)
#97 Cylinder Balance Fault #7
#98 Cylinder Balance Fault #8


Thats what ive gotten so far
Thanks for any help

[Robyn]

The 36 could very well be related to a failing PMD (whats mounted on the firewall)
Needs to be on a cooler out of the engine bay.



A DTECH PMD replacement is a good way to go. Just use the resistor thats in the port of the exisiting PMD

A good place to relocate the PMD is on a nice finned cooler down on the inside of the plate thats right under the radiator (Folds down from back to front)

The 97 and 98 can very well be faulty injectors.

Yank the injectors out and have them tested. #7 is the rear one on the drivers side (LH)

The #8 and all the rest on the turbo side are tougher to get out so have the 7 checked and see what shows.

From this point you can see wassup. If the 7 is shot then it would be a good idea to get all 8 rebuilt and set to specs.

With a used IP I would have the shop set the pop pressure at 2000 PSI on the injectors.

Give it a go and keep us posted

Robyn

[Hooptybass]

On the injectors ... should i my local diesel shop to rebuild them ? or my local parts store can get my remans for $25 w/one year warranty or new ones for 45 with a yr warranty ? Can anyone point me in the right direction for a Pmd for this beast ? Thanks Brian

[Hooptybass]

Well my injectors tested good ... I was told to try the noise filter on the pump but that didnt do any good .. Does anyone else have any sugestions ? my local diesel shop said they would hook it up and find out whats a matter for bout 50 or 60 bucks

[rogers]

My vote is that the IP is pulling air into the system somewhere. Do you have a good lift pump? Is it providing solid pressures under sudden acceleration? Check and tighten all the lines.

[Hooptybass]

Well i finely got around to geting it looked and and they said they thought it was the injectors b.c they have had that happen to one of there own there by the way ti sounded . sooo i needed to put new exaust manifolds on it so when i had them off i put in new marine injectors and glow plugs .. so when i get all done and start it up .. Bam still doing about the same dam thing . same 3 cylinders are gettin fault codes and and #36 code pulse lenght too long
Does anyone have any other ideas .. im hoping its not my IP but not sure what else to try . Ima try and check all the fuel lines this week . I gotta figure out how and where to hook up and check my pressure from the pump .
Thanks Brian

[ronniejoe]

Be sure to follow up on all the advice that you've been given so far. It's hard to tell from what you've written, but it doesn't sound like you have.

There is a quick and easy way to see if your lift pump is running. It won't tell you what pressure it is generating, but it will tell you if it is running. With the engine running, loosen the thumb screw bleeder valve on top of the filter. If fuel squirts out under pressure, then the lift pump is running. If no fuel squirts out, the truck will probably stumble and die. This means the lift pump is not running and the IP sucked air through the open bleeder valve. A non-functional lift pump will cause missing, stumbling and any other number of problems.

The code 36 could be caused by bad grounds. Go to the content side of the web site and read all the troubleshooting information that More Power has compiled over the years regarding this code.