Ok here is the problem and it is weird I drive a short distance lets say 50 miles or less shut off my truck go in do what I have to do come out and start it back up. Well the engine will start lobbing from 800-1200 RPM and then it will die when I try to start it it won't start BUT after I shut the key off and turn it back on it will start and run fine idles a little high but will eventually settle down to 800. Now this won't do it all of the time and there is nothing that set it off like the AC running or it being hot I can drive down the block to the store and have it happen or drive to the next and it will happen BUT I can drive it hard 75 MPH for 60 miles pull in and get gas and it will start up and run great it just seems to do it on trips 50 miles or less. If I catch it and keep my foot on the throttle at about 1800-2000 RPM it won't do it. Any Ideas


Thanks


Rickhttp://www.dieselplace.com/forum/smileys/Confused.gif

It might be worth it to have a scanner reading the sensors while you go through this. Coolant tempature sensor or IAT could be reading low at start up causing a hard start. Every now and then this will happen to me and I'l get an 800 RPM idle but once I throttle it the RPM drops to 600.

This is a 93 so there is no sensor or anyway to get a code what I understand is that with the OBD 1 if the SES light doesn't come on there is nothing to read. Also with the JK cooling upgrade it the fast idle and advance aren't hooked up anymore (I wish they where)





Thanks


RickEdited by: radrecon69

I should have seen it in your signature. Could your fast idle be sticking? TDG, DieselPro or gmctd might be able to say more on internal operation of the DM pump. I have one but have yet to even turn the metering screw up.


What do you call the maechanical, DB?Edited by: quantum mechanic

DM pump? what are we working on here a John Deere? http://www.dieselplace.com/forum/smileys/Big Smile.gif


Sounds like your metering valve is hanging a little, try some lubricity additive and check/change your filters see if that fixes it. When's the last time the pump was rebuilt?

Texas Diesel


No it is a 93 Dually the IP was supposed to be rebuilt last year before I bought the truck I use Soy Shield or Power Service additive regularly. The weird thing is that sometimes that truck will take off like a bat out of H*LL I mean head jerking power I do have a 4" exhaust and the "Turbo master wast gate actuator"


Rick

Again, it sounds like a metering valve sticking...

You may want to check your lift pump operation or for the advance on the pump to be sticking, my buddies 93 wound up doing the same thing, the lift pump was an intermittent no work.


James

Are we talking pump rebuild or can this sticky valve be unstruck I don't think the advance is hooked up with that cooling upgrade you can't connect it





Rick

Pump rebuild :( I'd look at the Lift pump first though, pull you Fuel filter cap off and see if it is only half full, if it is, check the power to it. This was the problem on his.. We put the pump on THEN found this problem.

The Advance you disconnected is just a housing pressure dump to increase internal advance a couple of degrees, disconnecting it just disables the cold advance funtion, but does not affect the internal advance of the pump. I you have or have had any water in the fuel, that could cause the valve to hang. I would reccommend installing a clear line in the fuel system to determine if air is entering the system and also a gauge to make sure inlet pressure stays close to 5lbs. Check the filter/base for signs of contamination as well.

Pull the fuel return line off - top,front - put clear tubing from the pump and from the removed tubing to a jar, crank the engine and observe fuel flow from the pump housing as engine hunts idle speed.


Could be housing pressure outlet is partially blocked from dirt\junk, and\or HPCA Solenoid is worn.