Hi Folks, Hope someone here has some ideas to help me.

Truck died coming home from work and refused to start.
I pulled some codes and got an334 and 128 ( as i recall) The 334 is EGR closed voltage higher than expected and 128 is MAP vacuum circuit failure. I checked the vacuum line to the MAp and it had a small crack so I replaced it, but to no avail. I have 40psi fuel pressure on the rail and I have spark. Anything else I should be checking. Thanks Ryan

 

Wow interesting, I would maybe try disconnecting the battery for a few hours to clear the computer. During start mode, the computer ignores the Map and EGR sensors so you should atleast get a fire or two.

 

Can you test to see if the injectors are getting pulsed? Listen with a stethoscope or tube or check with noid light. Check power to injectors. Could prime the intake and see if you get a hit.

If you pull a plug you can do a rough timing check, see if it sparks on compression stroke.

 

Thanks for the replies guys. I took the the truck to a mechanic and he checked a few other things out. Said it has signal to the injectors and the timing is correct. It does turn over hard. He had a rebuilt starter and fresh battery so he tried that out and still turned over hard. He suspects internal engine damage of some sort. ???????? I have tried starting fluid and it usually will fire and run for maybe a second or so. I towed it back home and figured I'll mess with it this winter when I have more time. Any other suggestions/ideas/advice would be great.

 

Yeah, It could be the timing chain, slipped a few teeth. Or broke?Take the distributor cap off and see if it rotates when turning the motor over.