MDTAHOE

When the cel is flashing it is misfiring. Instead of guessing you need to take the truck to a qualified technician to run a series of test. In the long run it will save you money. I highly suspect you need to replace the injectors. The assembly has been updated. ( this is a very common problem)

timdogg1313

MDTAHOE
Thanks for the information. I had it at a dealership 2 weeks ago and they actually let me come back in the back and look at the codes when they hooked up the computer. The codes that came up where the o2 sensor bank 1, sensor 1 and that #2 & #4 cylinders where misfiring. I have changed the plugs on all cylinders and the o2 sensor as well. You said that you highlt suspect that I need to replace the injectors and that the assembly has been updated, but what do you mean by that (updated)? Is there anything special that needs to be done when replacing the injectors( o rings replaced, precautions to look out for, ect.)? Could it be I have a vacuum leak at one of the gaskets and should I replace those as well?

Thanks again for your help!

Dirtbike768

I am a diesel mechanic so i am just shooting in the dark and i have talk to a mechanic and just trying a few things before i take it to a shop. Thank you for the input. MDTAHOE about what would it cost to have them replace the injectors?

MDTAHOE

The injector (or spider) unit was orignally made with poppet type injectors. The new set up now has a electronic type injector at the end of each tube. 2 wires run down to it along side the tube to it. You have to remove the upper intake to do it. If I remeber correctly them parts are 300.00-400.00 ($360 seems to be what sticks in my head) And I think somewhere around 2 hours labor.

in2pro

If you are medium level handy capable you can change out the injectors, it looks more difficult then it really is, the important part is take your time and think before doing... I can post a few pics if you like

timdogg1313

in2pro,

Thanks for the information. Pictures would be very helpful. I don't mind tackling most things and get it right, but like to do research on the front end before I just dive right in and tear my engine apart since this is my daily driver. Any thoughts on the manifold gaskets? Should I replace those as well while I'm changing the injectors out? I don't know how to do a vacuum test, so any information on that would be helpful as well(if it can/needs to be done).

Thanks again,
Tim

MDTAHOE

Yes replace any gaskets you take apart

in2pro

I did this on a Saturday, make sure you have everything you need
poppets, injectors, gaskets (fuel meter body, intake and fuel line) anti-freeze you will need to remove the top radiator hose and snorkle to remove the intake cover.


correction: I did it on a Tuesday not a Saturday, I would plan for 4-6 hrs to complete that's taking your time and stopping for lunch and explaining to kids what you are doing

in2pro

continued..

I used all AC/Delco parts, if I recall the gaskets came as a kit, also replace the pressure regulator while you have everything off, the regulator looks like it should have something connected to it but it does not..

Note the paper towel in the TBI, that was for when I was removing the intake to prevent anything from falling thru to the intake

protect the cylinder intakes after removing the intake cover, I was under a tree (lol shade tree) and didn't want leaves or twigs falling on the windshield and sloping right off into the intakes.

DON"T for get to removed the paper towels before installing the cover back on. I did use paper towels with the reasoning that if they did go it they would cause the least amount of damage and would probably burn and pass thru the system if it did happen, a shop rag would not.

in2pro

a better view of pressure regulator and no special tools needed, worked with my 99pcs Craftsman set (okay yeah I have a few more pieces in it then it came with but nothing special )

the dog was supervising my work....