Help Truck Won't Start

[Josh281]

I installed the Exergy CP4 Fuel System Saver the other evening which consisted of pulling the stock Fuel Pressure Regulator out and replacing it with the one from Exergy. After the install the truck will not even try to fire, it only turns over.

I only pulled off the AC Compressor for the install. No other wiring or hoses were taken off.

I have tried to prime the truck over and over again with no luck. I took one mechanics advise by soaking a rag in unleaded fuel and placing it over the air intake. This still would not make the truck fire or even try to which I find odd.

I also put the old Fuel Pressure Regulator back in and it still wouldn't start. I have tried resetting the computer which also didn't work.

The truck is not throwing any new codes. Only codes I have are P0201 and P1224 which I had before this install and the truck ran fine.

I'm guessing there is air in the fuel system or something electrical was disturbed.

Does anyone have any suggestions??

Thanks

 

[torqued2dmax]

Do you have a lift pump ?

 

[Josh281]

No I don't have a lift pump.

 

[Josh281]

I also forgot to mention this is a 2011 LML with 192K miles.

 

[gmduramax]

Step one. Shoot the mechanic you took advice from.

Can you log rail pressure?

 

[Josh281]

Mechanic said rail pressure was .5mpa

 

[gmduramax]

Is the truck primed properly? How long have you tried to crank for?

 

[Josh281]

We primed the truck several times with the primer and using the set screw. On average we cranked the truck three (3) times until the truck timed out on cranking. We would then prime it again and start the process over again.

I did crack the lines on two (2) injectors. The first injector had a steady stream of diesel coming out as we pumped on the primer. The second injector only had drips for awhile priming but eventually developed a steady stream.

 

[gmduramax]

Try having someone pump the primer on the filter head while cranking. I don’t remember how long the truck lets you crank for. I had a truck take a minute of cranking before it would fire.

 

[Josh281]

We tried that yesterday for sometime. Felt like I was giving CPR.

I did notice that when I would pump on the primer it did get pretty firm. Then when I had someone start the truck while still pumping on it, it immediately went spongy and stayed that way while cranking.

Also I could prime it until it was firm then walk away for a few only to come back and find it spongy again. I'm brand new to diesels and don't know if that is common or sign that I'm losing the pressure somewhere.

 

[torqued2dmax]

Be very careful opening fuel lines if you do not know what you are doing because the high pressure lines are 26,000 lbs not 2,600 like a pressure washer , they can cut pieces of your body off !!!

 

[Ron Nielson]

I think you still have air in your lines going to the injectors. Once the air is completely out, the engine wil start. Diesels are notorious for difficulty in starting when the fuel system has been interrupted or run out of fuel.

 

[Chevy1925]

Be very careful opening fuel lines if you do not know what you are doing because the high pressure lines are 26,000 lbs not 2,600 like a pressure washer , they can cut pieces of your body off !!!

negative. all they will do is dribble/flow out fuel. cranking, its only going to build 5-6k max as that is all starting calls for, then the fact the pump sucks so bad at providing volume that a cracked open fuel line would be liked pulling the garden hose off the pressure washer while running. just fuel coming out in a small stream and next to no pressure.

 

[2004LB7]

I've had luck after being in a similar situation with pulling the regulator connector off. This would put the regulator at max pressure. Then when it starts you can put it back on. I've also pulled the pressure sensor connector (making the ecm think the pressure is high) encase the ecm was "waiting" the the pressure to come up before turning on the injectors.

Not sure it actually works but after doing what you did for an hour and then doing the above it fired up

 

[FC5452]

Did you try pressurizing the return line, the peizo’s need return pressure to open.


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[Josh281]

I will try all the above methods after work and report back. Thank you to everyone that has replied to this thread so far. Keep the ideas coming and I will try them all in a couple of hours.

 

[torqued2dmax]

negative. all they will do is dribble/flow out fuel. cranking, its only going to build 5-6k max as that is all starting calls for, then the fact the pump sucks so bad at providing volume that a cracked open fuel line would be liked pulling the garden hose off the pressure washer while running. just fuel coming out in a small stream and next to no pressure.

I was talking about if you were under the hood and someone is cranking the engine over and it starts and they have the throttle half open and it immediately revs to 2500 rpm for a split second , I do not think it would be only 5000 lbs coming out of a high pressure line that is just barely cracked open , when it happened to me I was glad no one was near it because it looked like it was going to cause a lot of damage to someone if they were in its path !

 

[kiwilml]

Did you try pressurizing the return line, the peizo’s need return pressure to open.


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This, my brother ran into this problem one time with no start issue and pressured the return line with air and it fired right up..

 

[Josh281]

UPDATE: Tried all the suggestions you guys posted with no luck. I did end up finding out that I have really low rail pressure. I've been on the phone with Wehrli who had the same thing happen after one of their installs. They ended up doing a CP3 conversation and it started. Also waiting for the Exergy engineer to call me back. I ended up taking it to a mechanic shop and hope to know more today.

 

[RLeidel]

Can you please provide an update on what ended up being the problem and what the fix was? I am currently having the same problem. Thanks.