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6.5 running like crap after new IP install

J

JonnyTheKidd

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so i replaced my injection pump. I'm new to diesels. i got the timing close 2.9-3.5. but it is running like crap i bled everything the filter, return lines, injector lines cracked them 1 by 1. the truck was running fine with the old injection pump it was just leaking fuel and filling the valley. i took the new one off putt the old one back on with the marks i made lined up and ran the same as it did with the new one. in park it idles high around 1500rpm and wont come down even after it warms up. if i put it in drive it will even out and not sound so choppy but still sits around 1000rpm. it also gives itself short revs. here's a link to a video of it running, help would be awesome cause I'm lost as to why its running like this.

link to truck running


like to the Actual IP timing not sure if i should advance it more or retard it more


thanks in advance for any and all help!!
 
Welcome to the forum @JonnyTheKidd

install a clear piece of tubing on the return from the IP to the steel line. it's about a 6" piece. the tubing you can get at any hardware store and it does not need to be fuel rated. all your doing is checking to see if you have air in the fuel system. start it up and watch for flowing bubbles.

what it sounds like to me in the video is one of the injectors is not spraying fuel into the prechamber. have you loosened the line nuts on each injector one at a time while it's running to see which injector it is? the short revs sounds like that one injector starts to work momentarily then quits.


what scanner are you using? FYI snap-on scanners are known to give you incorrect timing readings. others may also do this. you really need one of two scanners to verify timing. a GM tech2 or a laptop with some software called GMTDscan.

Here is the summed up procedure for setting TDCO on your truck. get the engine up to full operating temp. loosen all three IP nuts so you can turn the pump. leave the top nut accessible to tighten up while your checking the actual IP timing. set it at close as possible to 3 deg. in my experience 3.5 is too much unless your timing chain is new (no slop) move the IP very very slightly one way or the other, snug up the top nut, start engine and check. each time you go to move the pump, DO NOT run the engine while trying to adjust the pump, very bad things can happen!! Once you get it to 3deg's there are two time settings on the scanner, you use the time set function while your trying to find and move the pump to get 3 degrees. once it's there, then while it's idling, start the timing learn function on the scanner. it will then start hunting for the TDCO. iirc -0.7 is optimal from GM but you can go as far as -1.90 before the check engine light will set a code. But you will have to remedy any current trouble codes prior to doing the TDCO learn function

trying to set the TDCO can be a hair pulling event, the key is to have pleanty of patience

Lets start off by getting the clear return line installed and post a video on it running so we can see if there is any air intrusion. biggest thing is with the intake off, replace all the rubber fuel hoses under there to and from the FFM (fuel filter manager located at the rear of the intake)
 
So on a 98 you can ignore all the time set stuff. That's for obd1. Go right to tdco learn get your number and then adjust to get the tdco you want. I'm wondering if you're stuck in time set and the computer is trying to adjust while it's running.
 
Your right AK, I saw him post 95 motor and was automatically thinking it was a OBD1 like mine. I see now his is a 98! the GMDTscan won't work for him but a tech 2 would.
 
The snap on mt2500 will work to set it but the number value is off. If he gets desperate he could always use the koko method and just read the value with a scanner
 
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