it misses and runs rough during startup?

I would start by replacing the fuel filter. Also, remove the vacuum line from the fuel pressure regulator, if fuel is present the regulator is bad and needs replacement. Check out the images (below). Please let us know what happens.

Thank you, Ken.

Is it possible to show that location with the entire truck in the picture with it pointed out? So, it would not have anything to do with that purge valve solenoid again, right?
Thanks
Robert Walbroehl

It could happen if the purge valve is stuck open. This is what we have to show you the location, use a flashlight to look under the truck you should be able to find it.

I installed a new purge valve solenoid that I bought on line. It wasn't very expensive so your saying that maybe that its bad??? How can I checked this new part which is impossible to get to. It did fix the running problem with the service engine light. What would they symptoms be if it where stuck open like you said.

Also its was very difficult to get the vacuum line back on so Im not sure of it clicked in place so if it is not secured and is peaking to atmosphere would that be like an open condition?

Purge valve solenoid? Sorry, the fuel pressure regulator is what I was talking about, you need to remove the vacuum line and check for fuel.

Okay, thanks Ken.
I fully appreciate all your help.

no problem sorry for the confusion, let me know if there is fuel in the vacuum line.

Okay, but I need to find it first.

Yep, it looks like it as at one end of the fuel rail.

Is it okay to buy aftermarket parts because the dealers want an arm and leg for OEM parts and if so, what distributor can you trust?

Oh yes, I like OEM over anything else, but it would be good with an aftermarket if needed.

I'm going to try to change this fuel filter myself but found out it's on the inside of the frame halfway down the side of the truck. So, I will need to lay sideways to work on it. I'm worried about fuel spraying once disconnected so how can I prevent that? Also, my tank is 3/4 filled. I planned already taking this fuel cap off to depressurize it but what else can minimize the mess? Thanks
OEM Delco price is $80.
O'reilly Microguard fuel filter is only $16.
Which one would you get?

I would go with the O'reilly Microguard fuel filter. Also, have a catch can ready when you loosen the fuel lines, just a cup full of fuel is all that will come out, and yes remove the gas cap. I have seen the fuel pressure regulator leak on these trucks which is inside the intake manifold. If this is the problem one or two or the spark plugs will be black so you might want to pulls the plugs out for inspection. Let me know how it goes.

I would like to check pressure but can't find the Schrader valve on fuel rail or a place to hook it up. Also, I want to get the old gas out of the tank so not much will spill. Can you use some tubing down then filler neck or will it hit an obstruction in the system? I don't want it to get stuck in the tank.

Here is a video that helps with the fuel removal:

https://youtu.be/Q5MH2gnyFH0?si=Mdt1CmF8lKX0FbHJ

They don't have a Schrader valve anymore, you will need to tap into the line.

This guide can help:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Please go over these guides and get back to us.

Thanks Ken,

I did find which looks like a Schrader valve hiding under a line on the fuel rail top. It has a black cap. Now I started the truck about 20 minutes ago and was not acting up much, so I took it for a drive. First stop sign idled okay. It accelerated up to 50 MPH and ran ok. Doubled back at 50 and still good. At each red lights idle ok. Not sure what it's going on but next start could be rough like before so I'll let you know. No engine service light either. Mystery. If I can keep driving it I'm going to try to get tank near empty and change that filter next. You think possible water in gas??

That is possible, you might want to try a gas treatment in the tank, also did you remove the spark plugs to see if the back two on the passengers side are dark?

No. I wanted to pull the vacuum line off the fuel pressure regular to see if it has fuel but still dont know where it is locates. That picture did not help. I could take some pictures of the engine compartment and send and maybe you can see it and tell me. Bought a Hayes Manual and it sucks for information.

Totally frustrating. My fuel is getting older and is going to cause more problems.

Yep, if you can upload images of the fuel rail it will help. It does not say but I think the fuel pressure regulator might be integrated into the fuel pump.

"The fuel filter/fuel pressure regulator is located on the fuel feed pipe, between the fuel pump and the fuel injectors. "

Did you change out the fuel filter okay? You may have a weak fuel pump. What was the PSI when you checked it?

Right now Im going to try to drive until the tank gets empty. I will try to get a pressure gauge but taking it out the last couple days for a sort run its ran good at 50 MPH. So I doubt think fuel pressure is low. I will try to check it with a gauge soon. Once the fuel tank gets empty Im changing the filter first and then just put a few gallons of high into it maybe with a little injector cleaner and see what happens. If that dont work then it will be fuel pump change time especially if I dont have the recommend 55-60 psi. What do you think. And thanks for all the help. I will keep you up to date.

Yep, that sounds like a plan. Have a good weekend.

Getting ready to change fuel filter. Plan on connecting hose to outlet of old filter and pickup pump feeding old gas into a glass 1 gallon jugs. Is here a way to energize pump without pulling relay out and jumpering 30 to the other contact which I think is 87.Not sure. I don't want to damage the receptacle shoving something in it. Hoping to empty they 10 gallons of fuel in the tank. Turning key in only energized the pump 2 seconds. Please advise.
Thank you, my friend.

You won't hurt anything by draining the tank.

Here is a video to help:

https://www.youtube.com/watch?v=Q5MH2gnyFH0&t=37s

Let us know what you find. Here are the wiring diagrams for the fuel pump.

Dear Ken,

First thanks for the help. Got back to my daughters after a week where the truck is stuck until we have a reliable fix. Put code reader on it and had the following:
PO300
Engine misfire detected
Fix assist
Affects one or more cylinders
Fuel metering fault
Fuel press low/ high
Fuel supply contaminated
EVAP system problem
EVAP canister saturated
EGR valve stuck open
PCV system vacuum leak
IC control circuit shorted to ground.
Ign system fault ( a coil )
Tbs-87-65-08
Tbs-03-06-04-030
Tbs-03-06-04-055
So I erased code and started truck was running fine. Ran around the block 6 times with no issues. Get back and decided to check fuel pressure with gauge hooked up to feel rail. Got 55lbs with key in and started and went to 60lbs. Decided to change fuel filter anyway. Unhooked output from old filter put in bottle and turned key in and off 4 time filling glass jar. Fuel looked light amber and crystal clear with no water. Changed filter which was a paint in the ass. Clips did not work that came with new filter and had to use the old ones. Finally got it on and fuel pressure went up to 65lbs. Truck still experience a studded when stopping down quick to raise rpm.

Dear Ken
First thanks for the help. Got back to my daughters after a week where the truck is stuck until we have a reliable fix. Put code reader on it and had the following:
PO300
Engine misfire detected
Fix assist
Affects one or more cylinders
Fuel metering fault
Fuel press low/ high
Fuel supply contaminated
EVAP system problem
EVAP canister saturated
EGR valve stuck open
PCV system vacuum leak
IC control circuit shorted to ground.
Ign system fault ( a coil )
Tbs-87-65-08
Tbs-03-06-04-030
Tbs-03-06-04-055
So I erased code and started truck was running fine. Ran around the block 6 times with no issues. Get back and decided to check fuel pressure with gauge hooked up to feel rail. Got 55lbs with key in and started and went to 60lbs. Decided to change fuel filter anyway. Unhooked output from old filter put in bottle and turned key in and off 4 time filling glass jar. Fuel looked light amber and crystal clear with no water. Changed filter which was a paint in the ass. Clips did not work that came with new filter and had to use the old ones. Finally got it on and fuel pressure went up to 65lbs. Truck still experience a shuddering or misses when stopping down quick to raise rpm.
Friday, November 1st, 2024 AT 3:21 PM

With all of these codes it seems like the PCM is bad, you can remove it and send it in for testing to confirm. Here is the location of the PCM and how to change it out. You can get a preprogrammed unit by searching Google or Ebay. Check out the images (below). Please let us know what happens.

See the photos below with the troubleshooting information. Sent they other day but not sure if received on your end.
Thanks for your advise.

Intermittent rough idle and missing. Code reader shows P0330 engine misfire detected.Fuel metering fault.Fuel contaminated.EVAP canister or EGR valve stuck open. I check fuel pressure 60# and fuel is clear.
Please help
Thanks Bob

This problem was previously sent and Ken replied. The fuel filter was changed but still has the idle issue. Also performed test with gauge at the fuel rail and a code reader. Code was P0300. See readings and info on the attachments.
Checked fuel output from old filter prior to changing it and it was clear with no water.
Purchased Lucas Complete Engine Conditioner and the stabilizer for the remaining fuel to see if that helps.
Truck runs fine and accelerates some time but when started up again it starts to buck and run rough and when I step the accelerator down quick it misses initially but then the RPM comes up okay.
Two months previously had a service engine check light and changed the purge solenoid valve which fixed that error code. Not sure of something in that system many have a problem. This truck is driving me crazy

Thanks for the help. Do you think I should start changing our checking some of the other possible things that are on the single PO300 code list in its suggested order like EGR valve, fuel canister, contaminated fuel before removing the computer and sending it out?

Did you remove the vacuum line from the fuel pressure regulator? and if so was there fuel present? Also I would remove the spark plugs to look for one that is dark or cleaned off to indicate a bad fuel injector.

I am going to try to find that regulator and let you know. So far changed purge solenoid valve, new fuel filter, checked for clean gas, and got a steady 65 lbs at fuel rail. Ill try again to find that regular and check plugs next.
Thanks for the help Ken once again. Battling cancer with 200k medical bills cant afford to have some one else doing it.

New update.
Reset code. Put Lucas engine conditioner in fuel tank. Headed home with no service engine light until 6 miles out. Stayed on without flashing until I got home. Truck ran normally. Once home put code reader on it and got.

New update.
Reset code. Put Lucas engine conditioner in fuel tank. Headed home with no service engine light until 6 miles out. Stayed on without flashing until I got home. Truck ran normally. Once home put code reader on it and got PO420 catalyst system low efficiency. Also, a small red icon that says EVA.

You could have a partially clogged catalytic converter, please go over this guide to see if that is the issue.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Please go over this guide and get back to us.

Checked the cat after driving awhile temperature at input was 303 degrees and the output was 500 degrees. Ran truck about 5 miles with no light up and 5 miles back. Then went a 33-miletrip and back to the store and there was no service engine light yet. Afraid to go too far because I can't afford a tow truck trip. This is after putting the Lucas complete engine conditioner in two weeks ago and driving it back 14 miles it which time got the light halfway back. Since then, reset code and no light yet with these short runs. Any suggestions? Thanks
Bob

The catalytic converter seems to work okay. Keep driving it so we can tell if it is fixed, it could have been bad gas or the system has readjusted.

Okay, stay tuned.
Thanks again,
Bob