Sluggish Acceleration Hummer H1 6.5 non turbo Diesel

[whitehumh2]

It is loacted at the driver's side rear of the block on N/A Diesels and directly in the V of the block right in front of the Turbo on TD engines. If the pump is not pumping because it has no power, that switch is most likely your cause. I have replace a few of them on both types of engines over the years.
 
The one on the TD is tight to get to but doable with the right tool without taking much apart. On the N/A diesels you will need to remove the dog house/dash to access it.

[Roy]

This one is accessible from the engine compartment with more room than the turbo version

[Skenth]

Well I do hear the pump rattling...so I'm assuming I have power getting to the fuel pump. I'm trying to find someone local to do the fuel pump and filter for me. ( I checked the air filter and it's clean...just as an aside)

[GreenMeanie]

Lets go over this diagnostic for a second.
Fuel is getting to the engine if it revs up in park. Taking it out of park should not change anything. You say the accelerator doesn't work in reverse or drive meaning the engine rpm does not change. Is this correct??
Did you try moving forward with the shifter in first gear position, and then again in second gear, and again third gear. Also check the transfer case lever to make sure it is correctly set.
To me it sounds like a pressure switch problem in the valve body most likely due to an electrical fault or perhaps the pressure switch froze up. Not familiar that much with the NA trucks but i assume you still have a 4l80 transmission controller of some sort.along with an accelerator peddle that has a position sensor. I would attempt to pull trouble codes to see if any pedal position sensor codes come up prior to spending cash on things that may be OK,
If the accelerator is mechanical perhaps the linkage is bound up between the pedal and the injection pump but you did say it revs in park so im not so sure about that. Still there is a TPS in NA trucks that is famous for doing what you descibe. Should also pop a code i would think.

[Roy]

[quote="GreenMeanie"]
Lets go over this diagnostic for a second.
Fuel is getting to the engine if it revs up in park. Taking it out of park should not change anything. You say the accelerator doesn't work in reverse or drive meaning the engine rpm does not change. Is this correct??
Did you try moving forward with the shifter in first gear position, and then again in second gear, and again third gear. Also check the transfer case lever to make sure it is correctly set.
To me it sounds like a pressure switch problem in the valve body most likely due to an electrical fault or perhaps the pressure switch froze up. Not familiar that much with the NA trucks but i assume you still have a 4l80 transmission controller of some sort.along with an accelerator peddle that has a position sensor. I would attempt to pull trouble codes to see if any pedal position sensor codes come up prior to spending cash on things that may be OK,
If the accelerator is mechanical perhaps the linkage is bound up between the pedal and the injection pump but you did say it revs in park so im not so sure about that. Still there is a TPS in NA trucks that is famous for doing what you descibe. Should also pop a code i would think.
[/quote]
its not the cable as the throttle does work,not the trany as it goes into gear and moves.
This truck lacks throttle response. Fuel prssure has not been checked, just hear pump rattling.
Fuel is not greatly needed in park ,in drive we need more fuel to get revs up......

[Skenth]

You are right that it revs up in park but when in gear, no change in rpm. I tried in 1st, 2nd gear as well as L or HL and still the same sluggishness. The accelerator is pushed to the floor and I don't hear engine Rev much in gear. At idle, it revs up the way it should. One day it didn't start, so I added the diesel911 to the fuel tank and it finally started...a I'm leaning towards fuel delivery problem. I'm not too mechanically inclined so I don't have tools to test the pressure or know how to change the pump or filter.


Just tried this morning...I unplugged the power connector to the fuel pump and truck started just fine. So that confirms that u dont need fuel pump to get started. I checked the connector and was getting 12 volt (so power supply is good). when I reconnect the power adapter, I hear pump running...but am not sure how much it's pumping out (don't have the tools or know how to do it)

[Skenth]

I disconnected the power to the fuel pump and the connector reads 12 volts...so I am getting power from the harness to he pump.

[GreenMeanie]

Im still betting on the TPS or a 700 series trans code.
Read this thread here to see if any bells ring
http://www.thetruckstop.us/forum/threads/1995-hummer-h1-throttle-position-sensor.35435/

[Boeing Jet]

There should be a drain tap in the left front wheel well.If it is not seized, when lifted, fuel /water will drain from filter.

This drain works best while truck is running on idle

[Boeing Jet]

Hey Sonny. Give me a ring when you get a chance. We can arrange a time and I'll come out and show you how to check your fuel pump and how to change the fuel filter. 416 951 3290


Markus/Boeing Jet