Shacks, rattles and DOSEN'T roll !!

[Fire54Medic]

HELLLPPPP !!! Ok, This is the first time on asking a question and for help online, but here goes. I have a 1999 Chevrolet Tahoe 2wd, 5.7 Vortec. Mileage unknown. I have changed the cap & button, spark plugs and Cam shaft position sensor. The reason I have done all these, is at around 70 mph, It starts to shack, (enough to where I have to let off gas) and misses, throws a SES code (misfire cyl. 3 sometimes cyl. 5) and acts like it boggs down, like no fuel, then catches back up like normal. Or when I pull out from like a store and give it gas it boggs down and doesn’t go anywhere till I let off the gas then get back in it..if I stay in it, it will back fire. I drive to and from work, around 200 miles 3 days a week. It will drive fine on straight stretches, but it seems like it only does this up a hill or rise. By the time I get to a parts store to read the code, I have driven on a good straight shot and the SES goes off, and no code are present. I’m tired of playing a guessing game, replacing an item to see what might fix it. Can someone please help me on what can be done next…ughhh..

 

[2Canoes]

Have you tried a new fuel filter?

 

[Donnie Yukonie]

Moved this to Engine and Drivetrain ,

As for your problem Have you checked your Fuel pressure?

 

[Fire54Medic]

Fuel Pressure good tested not to long ago, fuel filter changed also forgot to mention. Also I just did this on way back from store. It started shacking going up a small hill, so I pulled it down in neutral and it quit immediately, put it back in OD, started again when giving it gas, Neutral-stopped again, this time put in drive (3rd)- started shaking..got to top of rise and straight stretch it smoothes out and stops..When I went to town didn't do anything.

---------- Post added at 12:57 PM ---------- Previous post was at 12:56 PM ----------

Moved this to Engine and Drivetrain ,

As for your problem Have you checked your Fuel pressure?

Fuel Pressure good tested not to long ago

 

[Gzes]

Does it have enough gas? On my del sol when is low it does that. My fuel guage doesn't work so that's how I know It needs gas

 

[retorq]

Del Sol's are slow pieces of poo

thetruth.com

 

[Fire54Medic]

Yeah, plenty of fuel, does it on full tank and anywhere in between...

 

[retorq]

You didn't say spark plug wires, check those, they can be bad but look fine ...

 

[2Canoes]

When I think I might have a bad wire or coil, I wait until it gets dark and look at the engine while it's running. Just look for the spark. You probably knew that trick, but if you didn't...

 

[SunlitComet]

Verify fuel pressure again and when you are at the parts store have them plug in again and if possible search for pending or stored codes if they can. Also see if they can see live data and verify that the scanner rpm readout matches the dash tach at randomly selected throttle positions. It does sound like your pressure is off. Tho since you mention it happens on inclines it makes be think a valve is sticking.

 

[Fire54Medic]

Ok here’s the latest. Heard might be the EGR, so I unhooked it and it ran somewhat better, so I took it off and cleaned the piss out of it, it was blacker than black with a lot of build up around the 2 holes. Also person said might be torque converter causing shack, advise me to go to parts store and buy this Shutter lube you add to you transmission fluid..and I did, I'll try anything at this point. So far, it runs like a scalded dog, but I'm not holding my breath, just waiting on the SES light to come back on...I'll keep everyone posted.

 

[Fire54Medic]

UGHHHHHHHH !!!!!!!! Spoke to F'n soon. was driving home from work last night, had cruise control set on 70, then about 45mins later..it just turns off, like someone turn the key back to the ACC position. I was listing to the radio, it stayed on and the lights on dash cluster came on as well..(Batt,oil light, etc)..no motor activity..I put it in neutral and coasted over to side of road...turned off switch, headlights etc.., then tried to start it .NOTHING, engine just turns over..I can hear the fuel pump running, so don't think its that, since days before test pressure and it showed good,
So here's whats done, New plugs ( E-3's) , cap, button, wires, Crank Shift Position sensor, and cleaned EGR Valve. I'm now lost, still no SES code, I hate the guessing game..but, what should I try next???

Also would like to say, the day before and the morning I drove to work, and on way home till it happened( day after cleaning EGR) my HOE ran like a scalded dog, never missed a beat, I was happy... then.....knocked back to square 1

 

[SunlitComet]

SCRAP THOSE E3 SPARK PLUGS NOW MISTER.
Use only Delco 41-993 or Autolite XP605 or plain 605's if you need a plain copper plug core for some reason. But check your egr again to make sure something did not lodge it open as well. BTW if you have not heard yet use only delphi or delco sensor on your vehicle.

 

[retorq]

Yeeeeeeeeah people hate on those plugs here, someone got some vortec ones, put them in an old school head and they actually touched the piston so now they are garbage lol.

Check all the wires and make sure none are frayed would be my next step.