sweet, i did not think cutting the lines was a good idea, but wasn't quit sure what you ment.

thanks
Jes

 

I tapped into the fuel pump inlet with a clear hose and there were no air bubbles coming through. so is my next thing to have the injectors flow tested?

 

Another notorious cause of bad idle is low return fuel pressure. There is a return pressure regulator at outlet of injection pump to restrict flow and allow inlet pressure to build and keep IP happy with with fuel supply. I was told to take some vise grips and restrict flow on return line by Cummins BC (in Surrey,BC) to test it. Of course chose a section of rubber line that is not going to get damaged by squeezing and do not run long with totally squeezed off(pump cooling is affected). If it smooths out then regulator has dirt in it and leaks or spring is weakening or rust causing sticking (fuel contamination).

 

Um.... Not to be a PITA, but you are referring to what sounds like the P7100 pump on a 2nd Gen. There are no rubber sections in the return line on a VE'd truck.

Daniel

 

Check the valve adjustment first. It's free, and if you have a bent pushrod or some other valvetrain problem it will run lousy.

 

He is listed as a 92 so should be Bosch VP44 rotary pump which has rubber line from engine to frame rails.

I agree, check valve lash first since many owners completely forget they are to be adjusted every 30,000 miles on these early ones.

 

VP44 on a '92?

 

alright, i just adjusted my valves on my truck and my number three exhuat valve was way to tight so I adjusted it to .020 and checked the rest, tightened up a few valves maye one to two thousandths.

then proceeded to start my truck which immediatly started to make a popping sound , like it was backfiring throught the intake, made sure by pulling off the rubber hose off the air horn to make sure where it was coming from.

valves , push rods and spings all look fine,
injector pump?, injectors?
what about a sheared wodruff key for pump timing

am having the injectors tested on moday, looked a little dirty, not bad, some carbon build up

thanks
the input is appreciated
Jesse

 

You did the #3 exhaust at the wrong time if it was way too tight. Now it's not opening all the way.

 

I had thought i might ave but i went back last night and double checked every valve and, they were all correct, #1 IE, #2 I, #3 E, #4 I, #5 E, when the timing pin is in, then 360 degrees out, #2 E, #3 I, #4 E, #5 I, #6 IE, just like the book says., I also just checked the "sticky" to make sure and they were the same.

 

any help? I could use some more input on what is wrong with my truck. i.e. blown head gasket, injectors, injector pump?

thanks jesse

 

Did you use a barring tool or the alternator nut to turn engine over to adjust valves? If alternator nut then engine is turning backwards compared to barring tool method so valves are adjusted differently. Just thought I'd toss that out there, just in case...?

Oooppss, sorry, I posted in the middle of brain fade! I was doing a search and your thread came up and I responded before realizing the date, LAST MONTH!

 

my cousins 91 was doing the same thing,it ended up being the injecter pump,and it cost him nearly a grand to get it fixed.

 

Turning the engine with the barring tool, alternator nut, or a bolt on the h-balancer wont affect what order valves get adjusted in, once you determine which TDC (#1 or #6) you are at.

Are you sure you were at #1 (or #6) TDC when you started? I did a similar thing on my very first valve adjustment, and when I THOUGHT the timing pin engaged, it just went in from its resting place to against the cam gear; did not go into the slot/hole it was supposed to. The engine popped and sputtered, backfired, etc.
I took the pin OUT of the bore, stuck my finger in there while my then-fiance turned the alternator nut. When I felt the hole in the back of the cam gear cross my finger, I yelled WHOA!!.
Then I adjusted #1-I&E; #2-I, #3-E, #4-I, #5-E, left #6 alone.
I marked the h-balancer in relation to the belt and spun the engine 360 deg.
Then adjusted #6-I&E, #5-I, #4-E, #3-I, #2-E, left#1 be. Replaced valve covers and I was done. (I=Intake; E=Exhaust, for those who went to govt schools)

If your problem didnt start til after your valve adjustment, then I'd say it is related to said adjustment. It'd be a great, very unlikely coincidence if your pump or an injector pooped on you at the same time.

Daniel

 

Thanks for clearing that up on the rotation versus valve adjustment procedure, Daniel. I had heard the using alternator nut revesed the order but haven't adjusted my own valves yet to find out.