Lowrider
Peace out.
If I unplug the fuel pressure sensor on the r/s fuel rail it dies.
If I unplug the fuel pressure regulator there is no change that I can see, from what I know it's supposed to go to full pressure
which it does not.
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Woes with a 2004.5 LLY Dmax repeated P0089 Fuel pressure regulator codes.
- Thread starter Lowrider
- Start date
If I unplug the fuel pressure sensor on the r/s fuel rail it dies.
If I unplug the fuel pressure regulator there is no change that I can see, from what I know it's supposed to go to full pressure
which it does not.
Lowrider
Peace out.
Did you ever get the code figured out on that Dmax you have ?
Now that I thought about it for a bit, I think I got ahead of myself last night. I'm guilty of speed reading and missed a couple key points. And it doesn't help that I've been away from the biz for 5 yrs either...thank gawd!! lol
From the beginning, you said it needed fuel lines when you purchased the truck and you replaced all. Did it run ok and no current eng light/codes prior to all the fuel line replacement? Any history codes stored prior to your work?
After you did all the lines, you stated you had code 1093. That right there tells me there's a good chance it was something you replaced or disturbed>>>IF it wasn't there when you 1st purchased the truck. Did you also replace the 2 rubber fuel lines behind the drivers side cyl head? They're known for problems with age and high mileage, fwiw. Next would be the filter hsng. You replace it with a GM unit? Some aftermarket have known issues.
From the beginning, you said it needed fuel lines when you purchased the truck and you replaced all. Did it run ok and no current eng light/codes prior to all the fuel line replacement? Any history codes stored prior to your work?
After you did all the lines, you stated you had code 1093. That right there tells me there's a good chance it was something you replaced or disturbed>>>IF it wasn't there when you 1st purchased the truck. Did you also replace the 2 rubber fuel lines behind the drivers side cyl head? They're known for problems with age and high mileage, fwiw. Next would be the filter hsng. You replace it with a GM unit? Some aftermarket have known issues.
Unplugging the press sensor while running should kill it as that will cause max press of about 25K psi. Not sure about the regulator being unplugged, but IIRC that's normal.
Try this...key on eng off, what does the rail press read? Should be around 150-250 psi
Still KOEO, unplugged should read 25K psi
If the eng is still cold from an ovr night sit, Don't start it yet.
Also, by chnace do you have the vac gauge that connects to the port on the RF side of the eng? If not, I'll get one. This will aid in diag.
edit: I missed where you said you replaced the rail press sensor...this is good, but do you still have the original?
Lowrider
Peace out.
When I cleaned out the tanks I found some shitty looking fuel in them, like orbs of shit floating around
and I was getting a few different codes, P1093 being one of them.
So I replaced injectors and injection pump, I did get a P1093 after doing this but I am pretty sure it was the ebay fake fuel pressure regulators.
I haven't any other codes other than the P0089 once I got a legit Bosch regulator.
New fuel lines from tank to just below left side valve cover where they are metal from that point.
Filter housing is a aftermarket but it has upgrades like a metal bleeder screw.
and I was getting a few different codes, P1093 being one of them.
So I replaced injectors and injection pump, I did get a P1093 after doing this but I am pretty sure it was the ebay fake fuel pressure regulators.
I haven't any other codes other than the P0089 once I got a legit Bosch regulator.
New fuel lines from tank to just below left side valve cover where they are metal from that point.
Filter housing is a aftermarket but it has upgrades like a metal bleeder screw.
Lowrider
Peace out.
There should a short 6-8" section of rubber hose from the tank lines to the lines behind the VC. They're for eng flex and AFAIK, they are on ALL Dmax
edit: yes the port by the ficm. No sweat, I'll grab the gauge from the dealer.
2nd edit: that shit floating in the tank was algea and nasty stuff that can cause havoc with a diesel fuel system. Hopefully you got it all when you cleaned the tank and replaced the lines. If not, maybe some shit found its way and stuck in the rail, ficm or someplace you haven;t touched
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Lowrider
Peace out.
Fuel pressure sensor plugged in -- 178 lbs (My scanner reads in KPA so it shows 1230kpa)
Fuel pressure sensor unplugged -- 26k lbs (Here in KPA is shows 1800000kpa)
Snap-off Solus shows same readings
Lowrider
Peace out.
You are correct, these are still there it's down by the cylinder head where I hooked up the new lines
ok good. I hate metric and converted the #s. I always switched the units with my Tech2.
Ok now that you confirmed the rubber lines and the rail sensor reads normal. Those rubber lines are suspect, but from experience they would cause the 1093 or related codes. There is also a fuel cooler underneath near the tank. Did you at least blow it out when doing the tank cleaning and lines?
There is also one specific rubber hose that connects to the inj pump. Another suspect hose that has burnt me in the past. These hoses that I mentioned can deteriorate from th inside and allow crap to circulate. Not saying that's what happened, but they need to be checked considering you've replaced just about evrything else. I acn only imagine the coin you've invested so far. As you said...your close, so don't give up. I'll help you find the cause one way or another
Ok now that you confirmed the rubber lines and the rail sensor reads normal. Those rubber lines are suspect, but from experience they would cause the 1093 or related codes. There is also a fuel cooler underneath near the tank. Did you at least blow it out when doing the tank cleaning and lines?
There is also one specific rubber hose that connects to the inj pump. Another suspect hose that has burnt me in the past. These hoses that I mentioned can deteriorate from th inside and allow crap to circulate. Not saying that's what happened, but they need to be checked considering you've replaced just about evrything else. I acn only imagine the coin you've invested so far. As you said...your close, so don't give up. I'll help you find the cause one way or another
Just thinking out loud...if one of the hoses deteriorated internally and the junk ended up in the rail, maybe that's what is causing havoc with fuel press or reguator and would explain why the problem is present at cold start, but goes away after shutting down and restarting.
Lowrider
Peace out.
Not getting any P1093's though, I have been trying but I can't get a P1093 to pop up anymore.
Only getting the P0089.
I didn't blow out the fuel cooler, I have changed fuel filters 3 times since I put the new lines on though.
The truck drove to my house fine when my buddy dropped it off and I took it for a ride before I did the lines and senders.
Balance rates on a few of the original injectors showed out of spec so I replaced them all.
Lowrider
Peace out.
I have thought about that too and wish I had taken everything fuel related off the engine and cleaned it while I had it out on the ground.
But then I thought the fuel filter should catch the crud, maybe not
Ok now we're getting somewhere and I'm getting a grasp of the timeline of everything. The rails need to be checked for sure. They suck to remove, but there could be some junk floating around. Pretty sure at this point that something mechanical not electrical is causing that 11K spike in fuel press. What I would concentrate on is actually finding the debris somewhere instead of just blindly blowing a component out.
But keep in mind I say what I did above from experience. After everything you've done, I would want to find hard evidence to prove my thoughts of debris or algea stuck somewhere, otherwise you could continue to chase your tail. I'm thinking I'll be headed to your place in a coupe days
which I'll be happy to do!
which I'll be happy to do!
Lowrider
Peace out.
This gunk was on the fuel pressure sensor when I took it out.
I will have to wait for a warm weekend to tear into the fuel rails.
If you want to read about what a nightmare this has been, I have a thread over at Dieselplace.
Awesome ! Just awesome
www.dieselplace.com
Lowrider
Peace out.
But keep in mind I say what I did above from experience. After everything you've done, I would want to find hard evidence to prove my thoughts of debris or algea stuck somewhere, otherwise you could continue to chase your tail. I'm thinking I'll be headed to your place in a coupe days
I will be taking it to the guy who I got it from later today to help him out with some computer shit, I expect it will act the same
throw the P0089, key off, start it backup, clear the code, it will drive fine, I will stomp the pedal a few times to get rpms and boost up
to see if will throw any codes.
Thanks for the DRP link. Thought that place shut down, but good to know the info is still out there. I'll read it later today...time to get my ass in gear as its noon already. I'll touch bases later for sure.
