How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dad Mechanic Your Own Question
Dad Mechanic
Dad Mechanic, Mechanic
Category: Car
Satisfied Customers: 202
Experience:  I have worked on everyting from Model Ts to 2012 Autos,
65581030
Type Your Car Question Here...
Dad Mechanic is online now
A new question is answered every 9 seconds

new injectors and glow plugs installed..drained..fuel filter

Customer Question

Hello,
I have a 1997-1/2 6.5 Turbo diesel Hummer H1. It was in storage for 2 years because
I needed to have new injectors and glow plugs installed. I installed plugs and injectors.
I dropped and drained the fuel tanks, replaced all fluids and fuel filter.
I bled the injectors and fired it up. It idles great. (around 800RPM) I tap on the
accelerator and the engine instantly revs up to 3500RPM. It has an electronic accelerator
pedal and I wonder if it needs to be replaced. I can't recall if the pedal gave me problems
before I put it in storage 2 years ago.
Submitted: 4 years ago.
Category: Car
Expert:  Dad Mechanic replied 4 years ago.

Dad Mechanic :

Sorry for your problem. I am here to try and assist you. Is the check engine light coming on ?

JACUSTOMER-zcx0xun5- :

Hello, thanks for responding quickly. No light.

Dad Mechanic :

I there any spot in the accelerator that is a differn't rpm in any position of the pedal?

JACUSTOMER-zcx0xun5- :

I have not taken it out of the garage for a test drive. I am about an hour away from the vehicle. I'll check out the

JACUSTOMER-zcx0xun5- :

pedal position and contact you at noon, E.S.T.

Dad Mechanic :

ok i'll check in later. Jim

JACUSTOMER-zcx0xun5- :

Hello Jim,

Dad Mechanic :

Hedllo!

JACUSTOMER-zcx0xun5- :

Just took it for a test drive. The accelerator is very touchy at the outset. A slight tap and it goes from 800 RPM to 2000 very quickly. At about 30 MPH it seems to act more like a big diesel engine. Very good power. I did notice some large

JACUSTOMER-zcx0xun5- :

puffs of black smoke when I accelerated.

Dad Mechanic :

well after setting for 2 years you may notice temporay problems you seem to have done what you should have after setting for a long time. it would seem that the reostat in the foot control has corrioded. brb

JACUSTOMER-zcx0xun5- :

It that a replaceable part?

Dad Mechanic :

I was looking online to see I run school buses an they have them and they do go bad and are replascable. they don't usually act like your vehicle but I'm not usually talking about setting around. I would guess the whole general motorsline would use the same controller. The biggest problem I have had with PMD unit on the injection pump. I'm still checking for the reostat.

JACUSTOMER-zcx0xun5- :

You mentioned the PMD unit on the injector pump. I have read in Hummer forums that the placement in these

JACUSTOMER-zcx0xun5- :

vehicles overheats them. I only have 53000 miles on it but what are the symptoms of a bad PMD unit?

Dad Mechanic :

Ok I just checked with my local chevy dealer and its avabilable. call a trottle position sensor

Dad Mechanic :

I'm at at work brb

Dad Mechanic :

I'm back sorry have to ans phone too. PMD problem are hard starting, quitting and not starting. the biggest problem is the positining on the back side of the injection pump. hidden down in the valley where there is no ventilation. I ended up making a long extention cable and moving it to where you would get air flow acrost it. always carry a spair. If you look on the internet you will find special kits.

Dad Mechanic :

Part No. 5714531


Sensor, Engine Speed

Sensor, Engine Speed 6.5,For 4L80 equpt Truck,both Turbo and N/A

Dad Mechanic :

I also found that it has an engine speed sensor also may be be your problem. Please accept if i have helped with your problem. Jim

Dad Mechanic :

I also found this picture for the trottle position sensor.

Part No. 5714530


Sensor,Throttle, Position

Sensor, Throttle Position, 6.5 N/A and Turbo with 4L80 Transmission, Military Only. May not be yours but simalar. Jim

JACUSTOMER-zcx0xun5- :

Sorry for not getting back to you. The key point that you overlooked was the black smoke on acceleration.

JACUSTOMER-zcx0xun5- :

I took it in to a mechanic and he diagnosed it was injector pump. I found one locally and installed it.

JACUSTOMER-zcx0xun5- :

I am sorry I can not give you a positive rating because you were pointing me in a wrong direction.