This truck came from Alberta so its all your fault.
Friend has had nothing but problems from the start with this truck.
I have done the VP and a set of RV injectors as well as a Fass 150 from Harry.
Then the VP failed even though we had lots of fuel and psi was 15.
Got a new one under warranty. Then the 150 died and Harry sent out a 90.
It died recently. So I decided we need to dig deeper and since we had two failed fass pumps we put my new Raptor 150 on the truck. We unhooked the Edge Juice and there was no boost reading on the display. Put in a new MAPS, cleaned out the tank vent, sealed everything up and seemed like we had a restriction. The truck would be hard starting and fuel pressure would drop. So the tank came down again after we ran the truck from a pail and no problems occurred. Checked the voltage at the pump. 12.7. Check everything back to the tank and as soon as we hook up the factory tank...same problem. So down comes the tank again and we go through all the connections and I got rid of the spring clamps and used gear clamps...started real nice and had 18 psi of pressure. We figured we had it solved.
This morning hard start...crank crank crank. FP 18, pump working. no codes.
End of day today hard start again. What could be the cause of the hard start? It as running perfect last night and now its doing the same thing.

We are at a loss with this truck. I have suspected the injectors from day one.
No fuel in the oil. No coolant leak or loss.

The wastegate is seized and we need to deal with that too.

Any suggestions or anything obvious we missed?

This might be a great truck for someone if it ever gets working correctly. I bet 11-10K would buy it and there has been a lot done to it...brakes, trans, pumps etc etc.

 

VP pressure valve on the outlet fitting. If its sticking open, you lose prime at the pump itself.

Also check the return line banjo fitting at the rear of the head. You could have a leakdown issue there as well

 

I didn't see that you pulled the sending unit and cleaned the pickup. Sounds like the prescreen could be clogged. You could just drop a draw straw in it and call it a day. And like the man said the overflow valve could be weak or broken spring. But killing lift pumps sounds like suction restriction.


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Here's a few thoughts for you Scotty....

Dad's '92 cracked the flexible hose in the fuel module between the top and the bottom. Hard to diagnose-finally narrowed it down to that when pressurizing the tank wouldn't show a leak. Homemade drawstraw fixed the problem.

Buddy had an '01 that started hard especially after sitting nose-up. Went to the dealer 2 or 3 times, they couldn't fix it. I had a look, checked the obvious stuff (return line on the back of the head, the return line T-fitting). Convinced him to get a new set of injectors, tubes and O-rings in the hopes of shotgun-fixing it to eliminate pulling things down 3 separate times. Turned out to have 3 bad O-rings on the injector bodies themselves-they had collapsed to the point you could spin the injectors in the bore threading the puller bolt into the top of them. Runs like a champ now. That was one I'd never heard of before.

I have an '02 here that I have chased hard-start intermittently on since I had it. The injection pump was the culprit once, even though it showed no codes. That was the last thing left to change-a swap to known-good injectors, transfer tubes, and new O-rings made no difference, and pressurizing the system again revealed no leaks. Last time it started farting around it had a hole rubbed in the supply line-this one was found by pressurizing.

My '01 has had the aforementioned loose return banjo bolt on the back of the head cause it some grief as well.

I took a spare fuel cap and put a Schrader fitting in it to allow pressure-testing the system. Have one to fit the older trucks and one for the newer stuff. I use a clip-on air chuck and a regulator to make sure that I don't explode the tank. Works awesome for finding external stuff, or even priming the system after a big job has been done. I have a Star fuel pressure tester setup that has a spring-loaded blowdown valve with clear drain hose-I use this with the valve open and the lift pump running to make sure there is no air coming through. Read somewhere about somebody doing the same thing with clear hose in place of the stock stuff on the return side of the pump. I have salvaged enough quick-connect pieces now I think to make a set of adapters to plug onto the stock lines to allow pressure or vacuum testing-Cummins test procedure is actually to pull a vacuum at the return fitting to check for air leaks with a Mityvac pump or equivalent.

HTH
Jason

 

The VP valve is what I was thinking. Its the third pump. How do I verify that? Does the return line have a check valve or something? I always thought it was wide open to the tank.

Yes pulled the screens, in tank assembly, put in a new dip tube with the Raptor...1/2" all the way, pulled it out and re did all the fittings. That solved the spikes on the raptor but not the hard starts after it sits for a few hours.

I will check the return line and banjo bolts. I can't get my head wrapped around the idea that the return line could be a problem with my mind set thinking that it just returns fuel to the tank. I better stop thinking that way.
I checked the washers on the injectors. I was also thinking maybe the connector tubes?

Thanks for the feedback everyone. I have the supply problem fixed. Thought I had the hard start fixed...it sure sounds good once running.

Wastegate is messed too. What was initially thought to be one or two items is turning out to be a bunch of items and for me this also appears to be a lack of preventative maintenance and age of the parts on the truck.

 

Yes there's a spring and ball check inside the return line banjo bolt that bolts to the vp. When you change the pump generally you reuse the fittings. So its likely not been replaced.

Can pull it out and push o. The ball see if spring is broke or weak. That keeps prime on the pump when you park it. If you loose prime it'll hard start every time.


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Scotty you running the stock fuel filter housing or you have removed it? I fixed my hard starting problem with my 02 by just installing the stock fuel filter housing. I must have tried everything to prevent the injection system from loosing its prime. Another problem leak spot is the tee connection at the back of the engine, its the return line. One that comes off the back of the head and return off the VP. Connector tubes leak if they aren't tight or have damaged orings on them.

Just consider this, I rather work on a VP truck any day of the week, than a CR truck. Wow, they sure messed a really simple engine design with all that extra junk. Not looking forward to ripping into my 2010 this fall. Was fighting last night with a coolent line at the back of the CR engine, the one under the exhaust manifold and you have to remove two bolts, one on the passager side and one on the driver side. Fun stuff my friend. That coolant line feeds the heater/transmission heat exchanger. Been thinking about adjusting that design back to a simpler 2nd gen design.

 

Yes stock filter currently. I switched the cap in case it was cracked...will check the rest of the possible culprits asap.

Thanks!

 

I ruled out the banjo at the back of the head for the return line. Still hard starts. I did get the wastegate to move. It was rusted. Not sure if its going to be free moving for long and will check it again when I get the truck back from the owner to check the VP return line banjo.

 

Still hard starting after it sits.
I found that the relief valve for the VP that goes to the tank was not even hand tight. I got all excited that we found the problem. NOT! I removed it, and checked it but I am not sure what to check for. There was no fuel residue around this fitting. I put it back in and this morning I got a text it was still hard starting.

Is there a way to test that valve?

What else could be causing the bleed down after it sits?

I have gone front to back and top to bottom with all the fittings, connections and washers/seals.

When the truck has prime it lights almost instantly. Thats a lot better then it was when the white omen arrived at my place.

on edit, the wastegate is seized again. If we can get this hard start resolved I am certain we will be doing the turbo/wastegate and exhaust.

 

Something is sucking down the fuel, the air has to be getting in at a high spot and bleeding down? I don't know what to say other than another line with a hole in it or a fitting thats cracked.

Did you try Infidels technique of pressurizing the tank (very slightly) and seeing if it seeps somewhere?

 

Apparently the place where the 3rd VP was put on, did the pressure test and found no leaks. This is the same place that he had the fuel pressure and VP checked about a month ago. I found the loose return fitting AFTER they were working on it. See where I am going with this? The place he took it to is not known for competence. Thats all I will say about that.

I was thinking that the only line that has not been changed was/is the hard line from the filter canister to the VP. I did not do that one because he has a tapped banjo on the VP there for his Juice fuel pressure sender. I wanted to take that line out and put one of my set ups on there. 1/2" line with metric adapters and run a real gauge.

Another thing that the owner sent out for repair was his Juice because it was not reading any boost pressure. He paid 137.00 plus shipping both ways and insane UPS fees to the tune of 315.00 total and the boost display still does not work even after they said it was fixed. New maps, all new sensors are on this truck now.

Once we get this leak down done, he wants to decide if he wants to do more or get rid of the truck. I think its a good truck and just needs this leak down resolved.

 

I'd pressure test it yourself Scotty to eliminate the air leak possibility. Then you know that's not an issue.

 

What all do I need to do the test? I am determined to get this truck done correctly. Its been awhile since I worked on a VP truck and I am enjoying it.

Also, how do I know if that valve on the return from the VP is bad? Visually the ball is at the end of the bolt head. To me this might indicate that its been pushed out and there is now an open flow to the return line. Or, I am thinking the wrong way with this part.
What is a replacement worth?

Thanks for the replies! It sure would be nice to get out west for a coffee and a few burnouts.

 

Do you have a fuel pressure isolator installed? If so the bleed screw on the isolator should have a ball bearing under it. If the ball is missing then the screw will still seal but allow air to enter the system when shut down for longer periods.