Hey it's me looking for advice again.

Just finished the IP swap and got it all buttoned up again and now she just cranks but will not light. It seems as if it isn't getting fuel to the injectors.

I did follow the GM manual directions for getting air out of the lines by opening the vent on the filter and operating the lift pump until fuels runs smoothly out. But it still will not start.

What is a feller supposed to do???



Mike

Is the IP wiring harness grounded to the top of the IP? It won't start without it.

make sure everything is plugged in proper. Should start with out any special bleeding. Was running before?

The truck ran but with DTC56 thus the swap out of the pump. I plugged each connector in and gave them a wiggle to make sure of a good connection.

I am not sure about the ground wire on the IP. Does it go front the Ip to ground or ground on the pump?


Mike

Just went and looked and yes there is a ground wire attached to the top of the IP.


Mike

Sounds to be still "air locked"

Crack open as mant injector lines at the injectors and crank over the engine a few times. If after 4 long cranks you don't get fuel, something else is amiss. You should get fuel dribbling out the loose injector nuts. You'll want to take 1-2 minute breaks between cranking sessions to help keep the starter alive.

try using some wd40 as starter fluild and let us know if it tries with that

Ok I'll open the injectors but how far open?

I already tried the old WD40 trick but will repeat it again if I get fuel to come out of the injectors.


Mike

Open the injector fitting a few turns, It should seep fuel without being all the way off, manually power the lift pump while you're cranking so there's no question about fuel supply to the IP. If it doesn't seep fuel in a few cranks, I'd pull the codes to see whynot, switch PMD's, the usual. Check the IGN I and II fuses as well as F sol and the others in the fuse block.

Alright then crack them open but don't need to remove the nut.

My lift pump has had a work around and is not powered by the ops but rather at the key on position.

I'm gonna try it here soon.


Mike

We install lots of DS pumps and never break the injector lines loose on a 6.5.
Would be nice to know if fuel is there.

Turn on the IGN, pull the plug to the ESO fuel solenoid, then reconnect it - you should hear the sol click as the valve opens and closes.

If ya cain't hear it, put yer hand on it, see if it 'thumps'.

FYI - 1/2 turn max to bleed the injectors - air is not quite as dense as Diesel fuel (even using that new math that keeps showin' up here - man, what happened to education in this country?), so 2-3 turns will only result in more air in the line.

Ahhhh excellent 1/2 turn got it....I hooked up the trusty Tech1 last night and still had the dreaded DTC56 like I had with that other IP. Think that might be just because the computer hasn't seen this pump in action yet?

If it is a dead PMD is that possible to be changed on the truck or do I have pull the whole stinking pump again?

How are the eyes recovering from the cataract surgery?


Mike

Unless you manually cleared your trouble codes, the computer will continue to display the dtc's with new IP.

If the pmd is bad, I'd get a remote harness and attach the new one under the bumper or on the inner fender well. It makes it a whole lot easier if you need to replace it again. No need to remove the old pmd in this case.

The old eyes are an order of magnitude better, thanks - old math, of course.

There is also several orders of magnitude orders of magnitude that you would get two IP's that would return the same DTC, and no other.

Faulty connections cause same failure symptoms as faulty sensors and attached devices.

I was fairly certain you had connectivity problems with the '98 IP - any EFI IP cannot PI unless it is connected properly.

So, I would start with all the connectors at the IP, then all those on that bracket behind the fuel filter.

Then I would start at the batterys, work thru the cables and all grounds, get the voltage up over +12.6 - that +11.somethin-or-other voltage you had will cause the Fuel Solenoid to drag, giving that particular DTC.

For the DTC56, you will need to check the Cal Res in the orig and the repl FSD - probably should start with a #5

Oi!!!

The batteries I was told are shot so...I'm gonna get a new pair today.

Way back when I replaced the underhood wiring harness I got a "new" IP harness also with the purchase. So...I decided in my infinite wisdow to replace the 95 IP harness with the "new" one. I did leave off the optical filter thingy that I had previously removed.

Do you know where the ground wire that is on the drivers side hold-down for the glow plug relay goes???


Mike

Ok I checked fuses that you recommended...all were fin. I also checked the Fuel solenoid via the ign switch and the fuse. I did hear it clicking as it changes position....Still no start....

While I had the fuse pulled I accomplished the clear the air out of the lines procedure by opening the vent on the fuel filter until it streamed free....Still no start....

I cracked all eight injectors 1/2 of a turn and cranked for about 15 seconds then two minutes off for cooling. I did this for a total of seven cycles and saw no fuel seeping out from the injectors....Still acts as if getting no fuel....

Gonna pull the intake and swap back to the other IP wiring harness. Then try the crank/clear the lines procedure again.


Mike

You should do only one injector at a time till fuel seeps bubble-free.

Would also be best to tighten the fitting while cranking, to seal the pipe while it has pressure.

Then wait a few for the starter to cool, do the next one - if it immediately seeps clear, tighten it and go to the next, ad infinitum.

As DP sez, tho, shouldn't really take that much to get it started, tho the time and experience factor is the major determinant for that.

You were correct!!! I found that I cut a wire when installing the intake manifold. Unfortunately it is the pink w/ black wire that connects to the wiring harness to the four wire plug that goes to the PMD.

So I have a "spare" on the old IP that I took off...but...what to do with that ground wire on the top of the IP??? I don't want to back out that on torq screw for fear of boogering up the seal and thus the IP...Can I cut and spice that one ground wire????

When I get it bolted back I'll only do one injector at a time.


Mike

Before you go too far try taking the fuel line off at the new IP to make sre fuel is getting to the IP. I have seen the fuel line crimped under plenum fuel flow checks good at filter and T fitting but none to IP.

So is it safe to assume (I know we are not supposed to do that) that if there are no kinks in the fuel supply line that fuel is going to the IP? Or is there another technique?


Mike

If you take the fuel line off right were it goes into IP and there is good fuel flow then yes fuel is getting to IP.