Not good news...it was ok last week....

[Randee of the Redwoods]

94 k3500, auto.
Crank damper-new.
head gaskets-new.
water pump-new.
Thermostat-new.
fuel filter-new.
glow plugs-new.
batteries-new.
alternator-new.
All above done less than 2 years ago.
This weekend, the engine has developed a bit of a shake. It starts fine(for now) but starts with what feels like a miss. Motor shakes feverishly during rev up. BUT, I can't tell if it's shaking because of a miss or a bad motor mount. No ses light. I'll check for codes and post an update. It did this yesterday as well but the shake worked out after a while and drove fine. Took 2 tries to start it to leave my destination and it shook again for a while after I got underway. Bad motor mount? Bad fsd? What gives? Drove to NC and back two weeks ago, flawlessly. Now suddenly all this problem.

[fshope]

Check for a fuel supply problem (clogged filter, leak in filter unit, leaking injector, poor lift pump pressure, etc.). It sounds like the fuel pressure is falling off while the rig is sitting and may be able to lose the shakes after the pump is able to push the fuel pressure back up and get rid of some of the air. When air gets in the system it can really make things run rough and sometimes the unit will fail to run all together.

Frank
:(

[Randee of the Redwoods]

If I rev the motor slowly, the shake is all but not present. But if I goose the throttle quickly, it'll shake the whole truck.
Just ran for codes and not good. 68-tranny slipping. That I already knew about. 84-? I saw it three times so I'm sure it as an 84 but there is no listing in the code list. 99-Accellator 5 volt reference problem. Could it be my gas pedal is going bad?
These codes were set with no ses or sas light. The tranny code I get all the time since my tranny is tired. The code 99 I'm a bit worried about. But what about that 84? I saw it. There's no mistaking it.
Does it look like maybe my gas pedal has just finally gone bad?
I will, though, change the fuel filter and rehab some parts of the fuel lines.

[bbudus]

Mine did the same thing right before it blew all the coolant out the exhaust. :eek: Turns out head cracked. Luckly there was no further damage to the block.

It started the same way though would shake and shimmy until it built up enough heat to create a seal. At least I assume that is what was going on. After a couple days of that it progressivly got worse. That was at 201k.

bbudus

[charliepeterson]

Code #84 is the APP circuit. Your service throttle soon light should come on. Take a good look at he harness from the pedal to the ECM. The ECM will limit the power if it thinks something is wrong with this circuit.

If the engine is shaking violently than a compression test should be done before you start dumping money into it. The other non scientific method is the smoke color and the hard top radiator hose before the "T" stat opens tests.

Good Luck

[gmenor]

Randee,
Where are you at in Stafford? Give me a yell back and we can do a link up.

George

[Randee of the Redwoods]

Cracked head? Thanks for the positive side note. As far as I know, it never smokes except the obligatory puffs in cold weather. Even now with the warmer weather, no smoke of any color. No service throttle or ses light to date. I'll check that accelerator harness as the time comes in. I'll be out of town this weekend but I'll get started as soon as I can. Thanks for the code 84 explanation. So maybe this is just a bad throttle pedal assembly? Anybody have a good spare laying around I can try?
gmenor-I'm in the Falmouth area. I'm 4.5 hours from Highpoint, NC and 4.5 hours from Angier, NC.
I live about 2 miles north of Fredericksburg.
Update-just checked the coolant level in the overflow canister and it is exactly where it should be: at the line marked COLD.

[gmenor]

I'm at my Stafford Office off of Route 17 (behind the CVS). I know where Falmouth is (just down the road about 3 miles). Want to do a link up tomorrow at 6:00 PM at the CVS? We can yank my my petal out and see if that is your problem.

[gmenor]

Here is my email address and I'll send my cell number to you.

gmenor@aol.com

[Randee of the Redwoods]

I'm afraid I won't be available this weekend but I will take you up on the offer when I get back. Look for my emails.
CVS on 17? That puts you like 5 miles from my house. When I get back Sunday, I'll email you and get some specifics on your location. I really appreciate the help.

Revved the motor more today. Had the hood up to check the upper rad hose and overflow canister. No bubbles in the overflow and the upper tube stayed squeezable like Nerf ball the whole time. I took the engine at least past the 100 degree mark. As I revved it, a couple times, it seemed a bit reluctant. Ever been in a car that had a miss in the engine? That's what my motor feels like now. Ever been in a car with a motor running rich? You know that occasional stumble you feel while accelerating? That's how my motor is reacting now at times. Still keeping fingers crossed.

[gmenor]

Randee,
I will be leaving tomorrow back to Fayetteville, NC. I will be back up here on Tuesday and Wednesday next week. Can we shoot for Tuesday evening? I'll look for your email and send my contact number.

George

[Randee of the Redwoods]

Sounds like a plan. I'm off work early enough to pull that off. I just don't know about driving to you. It may not make it out of the driveway.

[gmenor]

Randee,
Send your address to my email address and I'll send my telephone number.

gmenor@aol.com

George