HI I have a 1996 Chevy C3500 5.7 manual transmission. I let the truck sit for 4 to 5 months to have my transmission rebuilt. Drove the truck for the first time after all of the work was done. Broke down and was running like crap so I changed the following Plugs, wires , rotor , cap , fuel flitter, Ignition control module and coil ... I also put fuel treatment in the gas tank and went with high octane with non ethanol fuel. Still not running right bucking and jerking when under a load. with high rpms runs fine. NO CODES. I don't understand ran fine the day I parked it
03-02-2013 08:27 PM
Originally Posted by tommyboy8072002
HI I have a 1996 Chevy C3500 5.7 manual transmission. I let the truck sit for 4 to 5 months to have my transmission rebuilt. Drove the truck for the first time after all of the work was done. Broke down and was running like crap so I changed the following Plugs, wires , rotor , cap , fuel flitter Ignition control module and coil ... I also put fuel treatment in the gas tank and went with high octane with non ethanol fuel. Still not running right bucking and jerking when under a load. with high rpms runs fine. I don't understand ran fine the day I parked it
What kind of plugs did you put in it? What did you gap them at? If the motor has alot of miles (100k+) I would put platinum plugs in it.
03-02-2013 08:58 PM
I ran with ac Delco plugs.. Were gaped a 60 still ran like crap. so I was told to drop it down to 45 still not running right ....
03-02-2013 09:05 PM
You may want to check your EGR valve. May be stuck open or closed after parking it for a while
03-02-2013 09:06 PM
You may also want to check fuel filter and clean fuel system out
03-02-2013 09:39 PM
Should I un plug the EGR valve to check it. Or do I have to do something else to see if its working or not... sorry don't remember how to check to see if its working or not...
03-02-2013 10:23 PM
I also noticed that my rpms is unsteady.
03-02-2013 10:39 PM
Are you getting a RPM surge at idle? You can test the EGR with a hand held vacuum pump. First see if it holds vacuum. You can remove it and clean it. You can unplug the vacuum line and see how it runs. You can remove it and see if the plunger even moves or if its siezed up. See if will hold a vacuum first. Cant hurt to spray some carb cleaner around all your vacuum lines while its running to see if you may have a vacuum leak anywhere. Start there and work your way to removing and cleaning the EGR valve. Not a bad job on a small block chevy. Let me know what you find.
03-02-2013 11:13 PM
Ok . On mine all I have is a plug no line. So I will unplug it and see if it makes a difference. Will let you know what I find thanks...
03-03-2013 08:50 AM
I checked all of the lines and Egr valve seems to be running a little better. But now I have a pop in the Exhaust Manifold driver side every now and then. Never messed with the timing :confused:
03-03-2013 09:35 AM
if its a vortec , it may be developing a problem in the poppet (injectors)
you could run some seafoam or chevron with techron through it to see if that helps.
Just dump some in a 1/4 tank ( I like to dose it heavy) and drive till almost empty, then fill up and dump another can in it. Drive it a while, see if it clears up after a while , if not maybe it will set a code and help aim your diagnostics in the right direction.
Good move doing a tune up first. Nothing I hate worse than trying to diagnose a driveability problem with all the regualer maintenance items in the questionable area. Eliminating them is must for any good diagnosis.
Inspecting and / or replacement is needed.:thumbup:
03-03-2013 09:56 AM
Ok. Thanks. I will try that and see if it helps. And yes it is a vortec.
03-03-2013 10:06 AM
Have a question what about fire ball I noticed that one of the parts stores Carrie it. Should I try that or get the other stuff that you mentioned.. Thanks ...
03-03-2013 10:12 AM
Never heard of it. I know seafoam and Chevron techron works as I have used it dozens of times in the past 15 years or so. It works.