Truck won't start...

[98.5Cummins24v]

First off, let me say that this forum has been very helpful before, but I just can't seem to diagnose the issue this time. Hopefully someone has an idea on how to fix this.I installed my 4 gauge Autometer digital set(Boost, EGT, FP, and Trans temp) yesterday. Everything went in smoothly. Went to start truck up, wont start. Thought ok probably the fuel pressure, so cracked one of the lines, got fuel coming out, closed it. Tried it again. Wont start.:banghead: The FP gauge reads 0 while I crank, is that normal, or will it not register until I start the truck up? Any ideas??? Thanks ahead of time!!

[dripley]

0 psi would not be normal, but we need more info on your truck. Is it stock, are ther any mods done. Go to the user cp and fill out your signature with all you know about your truck.

[98.5Cummins24v]

0 psi would not be normal, but we need more info on your truck. Is it stock, are ther any mods done. Go to the user cp and fill out your signature with all you know about your truck.

Knew I forgot something!! haha. Ok so the 0psi is normal. What else should I be checking? Thanks!

[98whitelightnin]

If your lift pump is week you may not get any suction back to fire it. I would try loosening #1 #3 and #5 and see if you can get it to fire.

[KATOOM]

Zero fuel pressure is normal ONLY if you have set up your fuel pump to not run while the engine is cranking. From the sounds of it and because you say everything is stock, then you have not. Which means you should definitely be seeing some fuel pressure on your FP gauge while trying to start the truck. It sounds to me as if you've forgotten to re-hook something up or blew a fuse or somethings wrong and whats happening is that when you installed the fuel pressure gauge line, you released the "prime" in the fuel system and until the VP receives enough fuel to start and/or the prime is regained, the truck wont start. This is why you hear of guys having to crack their injector lines to bleed the air out. And if you're fuel pump isn't pumping while your cranking the engine then there's no way the VP will ever see fuel. Because you have an OEM lift pump, I'm leaning toward your lift pump isnt working (pumping) and your VP was sucking the necessary amount of fuel to run.....until now whereby the VP cant suck air to re-prime itself so.....

[98.5Cummins24v]

Zero fuel pressure is normal ONLY if you have set up your fuel pump to not run while the engine is cranking. From the sounds of it and because you say everything is stock, then you have not. Which means you should definitely be seeing some fuel pressure on your FP gauge while trying to start the truck. It sounds to me as if you've forgotten to re-hook something up or blew a fuse or somethings wrong and whats happening is that when you installed the fuel pressure gauge line, you released the "prime" in the fuel system and until the VP receives enough fuel to start and/or the prime is regained, the truck wont start. This is why you hear of guys having to crack their injector lines to bleed the air out. And if you're fuel pump isn't pumping while your cranking the engine then there's no way the VP will ever see fuel. Because you have an OEM lift pump, I'm leaning toward your lift pump isnt working (pumping) and your VP was sucking the necessary amount of fuel to run.....until now whereby the VP cant suck air to re-prime itself so.....

I was reading the threads about getting the pump to not start until running, but no I have not done that to it. I hear it whining for about 20 secs when I bumped the starter, and I tried that again several times. I cracked the lines open again, and fuel is coming out of the lines. I went through the connections, everything seemed fine. I did not however, check the fuses, except the ignition fuse. Should I just check them all? I dont think it's the fuel pump, I did at first, but it seems to be working as of now. Could my VP have died? I dont want to jump to any conclusions and I'm trying to eliminate all possibilities before I replace anything...especially the VP, ugh!!

[dripley]

Knew I forgot something!! haha. Ok so the 0psi is normal. What else should I be checking? Thanks!

I stated that 0 psi IS NOT NORMAL unless as Katoom stated you have your truck set up that way. My truck starts at around 10 psi, half my idle pressure. It is controled by the ECM unless your truck has been set up differantly. Some folks do set theirs up that way. If yours is stock probably not. What kind of lift pump are you using?

[98.5Cummins24v]

If your lift pump is week you may not get any suction back to fire it. I would try loosening #1 #3 and #5 and see if you can get it to fire.

Hmm, ok. I had only cracked open #1 when I did the fuel filter like 2 weeks ago and after a few bumps it started right up. I will have to try all 3 of those and see. Thanks.

- - - Updated - - -

I stated that 0 psi IS NOT NORMAL unless as Katoom stated you have your truck set up that way. My truck starts at around 10 psi, half my idle pressure. It is controled by the ECM unless your truck has been set up differantly. Some folks do set theirs up that way. If yours is stock probably not. What kind of lift pump are you using?

Ooops, forgot the "not" haha. The LP is stock, I haven't upgraded anything yet, I wanted to get my gauges in place first, I thought that was the best thing to do.

[KATOOM]

If you're getting considerable fuel out of the injector lines at the head when you crank them loose, then try more lines to see if your problem is simply air in the system. Also, are you sure you have enough fuel in the tank?

[98.5Cummins24v]

If you're getting considerable fuel out of the injector lines at the head when you crank them loose, then try more lines to see if your problem is simply air in the system. Also, are you sure you have enough fuel in the tank?

Ok, I will try the other lines mentioned. I have between 1/2-3/4 tank left. Should be plenty right?

[KATOOM]

Thats enough fuel but I should have been explicit by asking the question. I asked because its not to uncommon for someone to find that their fuel level gauge/sender is wrong and there's not as much fuel in there as you think. This was a far fetch reason for your problem but I thought I'd throw that out there.

[98.5Cummins24v]

Thats enough fuel but I should have been explicit by asking the question. I asked because its not to uncommon for someone to find that their fuel level gauge/sender is wrong and there's not as much fuel in there as you think. This was a far fetch reason for your problem but I thought I'd throw that out there.

Oh ok, gotcha. I have to wait until tomorrow morning to test the advice ya'll are giving, but I will update the thread. If you guys can think of anything else for me to check and how to check it, please let me know. Appreciate it guys!

[hex0rz]

Codes, check for codes. That would tell you for sure if anything was going on with the VP.

[98.5Cummins24v]

Codes, check for codes. That would tell you for sure if anything was going on with the VP.

Well, had my diesel mechanic buddy take a look at my truck. Turns out the lift pump had indeed died. Getting an Airdog installed. Thanks for all the help guys, I appreciate it! I have been spreading the word about this forum!

[cajflynn]

You would need to take the fuel system relay out to test fuel pressure when trying to start. The truck sends a on/off signal to the pump when starting. If you take the relay out you can measure the pressure without the pump cycling.

[Mopar1973Man]

... or just bump the starter and get the pump to run and test at that point. But that just a dead head pressure and no flow. True pressures is idle and WOT at highway speeds.