Hello all,

Just went out to start my 04 1/2 after being out of town for the weekend. It did not want to start and cranked for a while. It eventually started and seemed to idle fine. I have not driven it yet. I checked error codes and got p 0477 which is low exhaust pres. relay. Not sure what that means. Checked oil level and that is normal, I can hear the lift pump running at the tank, but I do not have a pressure gauge on that (my bad). The truck is stock as far as I know except for a Pac Brake, has 180,000 miles on it and ran just fine up until now. Any ideas? I do not want to drive it understand what might be going on and fix it as necessary. Thanks

 

This is what I have for P0477..

P0477-LOW VOLTAGE ON THE ENGINE BRAKE DRIVER

I could give you the trouble shooting steps, but it involves using the scan tool for all of it, so I don't think it would be very helpful.

I don't think that is what caused your long crank. Did it only do it that one time, or has it been doing it since then? (looks like you have not started it since)

Could be a slight leak in the fuel system, causing the system to loose prime. Make sure your fuel filter canister is tight, and the water drain is closed tightly.

Try cranking it again. If it acts the same, let it rest for a while, and before you start it the next time, just turn the key to 'on' and let the pump run for about 20 seconds before you start it.

Changed your fuel filter lately?

 

Thanks for the info on the code, the filter is fresh with the last oil change about 1500 back. It started fine the second time around. I will check around the filter canister and the water lever, but I do not see any signs of fuel on the ground anywhere. What about lift pump problems? I bought the truck from a dealer at 100k and now its 180k. From what I have read about this particular truck, my lift pump was retrofitted to the tank before I got it. What kind of life do in tank pumps have? Any recommendations for a pressure guage?

 

The lift pumps that are in tank have a pretty good rep. I have not heard any real problems out of them.

As far as a leak, you probably will not find fuel leaking. I would look at the top of the tank for cracked lines... in the area of this picture...



That's aftermarket lines... but you get the general idea.

As far as a gauge, I have Isspro, and I like them, but there are a lot more options out there. I lean toward the mechanical gauges, and I don't fool with the isolators, I run diesel straight into the cab. Opinions vary on that.

 

It is possible that there is a leak there. I noticed a little while after I bought the truck that I would get some fuel around that white ring when filling the tank all of the way up. Then I would have some fuel that found its way on to the ground. I just rarely fill the tank all the way up, and no problems. That makes it difficult to determine if there is something new going on. I guess that I should bite the bullet and drop the tank and get it squared away properly. Then I can inspect those connections closely and go from there. Thanks for the speedy help.

 

I personally would not drop the tank, I'd lift the bed if you have a few other people to help you, or a hoist to pull the bed up.

For me, it is a lot easier to deal with everything where it sits in the truck, then try to guess where it's going to bend or turn while it's on the ground. Just my .02.

 

Me again. Went out to my truck after not driving it for 2 days and it would not start, again. I turned the key on, waited for 15-20 seconds, nothing. I repeated this a bunch of times and no go. I then needed to put the truck on a battery charger for a while. I called a local shop that supposedly works only on diesels and the guy on the phone told me to turn the key on and whack the bottom of the fuel tank with a rubber mallet. I did this a couple of times and the truck started!?! I then went to Kragen and got a Holly inline fuel gauge and installed it on the inlet side of the fuel filter canister. I also replaced the fuel filter. When I turn the key on, it jumps to 10 psi and then settles at 9 psi at idle. Not sure what happens under load to this pressure (as the gauge is under the hood), but my troubles are at start up. I checked the codes again and nothing new there. Once the truck starts, it runs fine, smooth idle, accelerates normally, etc. Do I need to replace the lift pump, and if so, what is the flavor of the month for the best performance and reliability? I am tired of this and I do not want to wreck the IP. Thanks in advance.