no start

[Jrgicehc]

ok I just finished fixing my coolant leak. I replaced both of my heads, and while I was in there I did a harmonic dampener, injectors, glow plugs, CDR valve, and i relocated my PMD with the FSD heat-sync.

Now the truck wont start. I assume the fuel system is just air locked. The pump seems to be moving fuel because I had a leaky return line that I just replaced after the first few times I cranked it. So what do I have to do to get the air out of my system?

1997 K2500 6.5

[Jrgicehc]

ok just an update, I looked in the members section and found directions to start an airlocked system. I started to follow them on injector lines 1 and 3 and i could not get any fuel to come out, I even went as far as to take the lines completely off and there was still no fuel coming out. am I missing something?

[diesel65]

When you replaced the heads, did you reattach the ground wires by the passenger side rear corner of the engine?
Does the Service Engine Soon light come on when you turn the key to the run position?
When you relocated the PMD did you leave the old unit mounted on the injection pump? If so, then reconnect it to see if the new unit is the problem.

[Jrgicehc]

I did re-attach the ground wires to the head
the service engine soon light comes on when my truck is in the run possition along with the glow plug light and the rest of the bulb tests.
I am still using the old PMD which I had not previously had a single problem with, I did not purchase a new PMD.

also when the key is in the run position and I crack fuel bleed valve fuel squirts out. so I take it my lift pump is working.

[rhsub]

When you relocated the FSD did you use an extension harness, if so, remove the harness an plug the fsd in to the ip harness and try that, you may have a bad harness. Recheck all the connectors that you disconnected for backed out or damaged terminals.
Good luck
Ron

[Jrgicehc]

Ok I just connected a ground that I missed on the second battery, and I checked all my connections and they all looked good. but it still wont move any fuel to the injectors. any other suggestions? Im starting to get pretty frustrated with the truck, its been together for a week but I have not been able to start it.

[Jrgicehc]

When you relocated the FSD did you use an extension harness, if so, remove the harness an plug the fsd in to the ip harness and try that, you may have a bad harness. Recheck all the connectors that you disconnected for backed out or damaged terminals.
Good luck
Ron

I did not use an extension harness, I did have to extend the small ground wire to reach around to the grounding location on the FSD. that ground checked out alright too.

[DmaxMaverick]

I did not use an extension harness, I did have to extend the small ground wire to reach around to the grounding location on the FSD. that ground checked out alright too.


Where did you terminate that ground? How much did you extend it?

The PMD/FSD ground must be flawless, and it must ground to the pump. If it is anything else, you will likely have issues with fueling. Mere continuity is not enough with this one.

[Jrgicehc]

Where did you terminate that ground? How much did you extend it?

The PMD/FSD ground must be flawless, and it must ground to the pump. If it is anything else, you will likely have issues with fueling. Mere continuity is not enough with this one.

Oh I grounded it to the FSD bracket. im going to go out right now and switch it back to the pump.

[DmaxMaverick]

I hope that's all it is. I've seen/heard this too many times to count.

[Jrgicehc]

I hope that's all it is. I've seen/heard this too many times to count.

unfortunately I still have the same problem. frustrating..... any other ideas?

[Jrgicehc]

ok I just put a scan tool on it and i got a "P0238 turbo charger boost sensor A Circuit High" and a "P1656 second (2nd) gear start lamp control high circuit". also my calculated load is always pegged at 99% (im guessing it has something to do with the first code), and my coolant temp sensor is reading -38*.

My cranking RPM was around 100RPM. My battery voltage drops into the red when I crank it now. How fast does it have to spin up to get the injection pump working?

edit.. this was with a generic auto enginuity scan tool without the GM upgrade.

[DmaxMaverick]

Either your scanner is haywire, or you have some serious electrical issues under the hood. I wouldn't trust the data until it can be verified with a known good scanner (or with the GM upgrade). "Strange" codes are normal with the key on and engine off. They only really matter after the engine starts. Also, check your grounds.

You might still be airlocked. Pull the glow plugs you can reach (makes cranking easier) and loosen as many injector line nuts you can reach. Verify you have fuel pressure at the IP and crank until the injectors are wet with fuel. Once the injector line nuts are tightened, you should get a fuel spray out the GP hole. You need a minimum of 100 RPM cranking, so you may be borderline. Be sure your batteries are healthy and fully charged, and use a jump start vehicle if necessary. Don't crank more than about 20 seconds at a time, with 2 minutes cooling time between. Weak batteries cause the starter to heat quicker (and wear it out sooner). It can be tedious, but should prime within 5 cycles, usually 2 or 3.

[Jrgicehc]

Either your scanner is haywire, or you have some serious electrical issues under the hood. I wouldn't trust the data until it can be verified with a known good scanner (or with the GM upgrade). "Strange" codes are normal with the key on and engine off. They only really matter after the engine starts. Also, check your grounds.

You might still be airlocked. Pull the glow plugs you can reach (makes cranking easier) and loosen as many injector line nuts you can reach. Verify you have fuel pressure at the IP and crank until the injectors are wet with fuel. Once the injector line nuts are tightened, you should get a fuel spray out the GP hole. You need a minimum of 100 RPM cranking, so you may be borderline. Be sure your batteries are healthy and fully charged, and use a jump start vehicle if necessary. Don't crank more than about 20 seconds at a time, with 2 minutes cooling time between. Weak batteries cause the starter to heat quicker (and wear it out sooner). It can be tedious, but should prime within 5 cycles, usually 2 or 3.

how do I verify fuel pressure at the IP? and is that verifying that the lift pump is working or is it an IP verification? I will try all of that tomorow, I have the batteries charging tonight so hopefully they will crank better
tomorow.

anyone else who has some good advice please chime in.

[DmaxMaverick]

Unless you have a blocked line somewhere, pressure at the water drain (T valve at the thermostat housing) means pressure at the pump. Yes, it verifies the lift pump is actually pumping. The IP will pump fuel with a defunct lift pump, but not until it is primed. Air can be a real PITA, but you should be able to get past that if you follow the priming procedure.

[Jrgicehc]

Ok, I just took some glow plugs out and turned the truck over a few times and still no fuel. it was cranking way faster than before too. I do have fuel coming out of the water bleeder.

Where can I get some wiring diagrams for the injection pump? I think the next thing I want to do is verify that I am getting everything I need electrically before I do anything else. I have access to shopkey but they do not have any information really on the IP.

edit... nevermind i found some info on shopkey

[Jrgicehc]

When you relocated the FSD did you use an extension harness, if so, remove the harness an plug the fsd in to the ip harness and try that, you may have a bad harness. Recheck all the connectors that you disconnected for backed out or damaged terminals.
Good luck
Ron

I FIGURED IT OUT!

at first glance at the PMD connector I didnt catch it but when I went through with a wiring diagram and checked for everything I was supposed to have coming out of the PMD I noticed I didnt have a ground to the fuel solenoid on the front of the pump and when I disconneced the PMD connector I noticed the wire was backed out of the connector just enough so it wasn't feeding the solenoid a ground.

thanks for all the help and advice guys. My truck is running great now.

[DmaxMaverick]

Good deal! More often than not, it's something simple.