Code 13 29 62 84 99!! HELP!!!!

[cheyenne1500]

13 = Engine ShutOff Solenoid Circuit Fault

29 = Glow Plug Relay Circuit Fault

62 = Turbo Boost Sensor Circuit Low

84 = Accelerator Pedal Position (APP) Circuit Fault

99 = Accel Pedal Position (APP) 2.5 Volt Reference Fault

Yes..i have problems. Truck runs like poo. Wont down shift under full throttle. Lack of power. Eng knocking at full and half throttle (sounds like some one pounding on the block with a air hammer!). I have Replaced the Lift Pump, OPS, fuel filter and air filter. Replaced Vacuum lines and checked vacuum before the wastgate: 13 - 14 Inhg. Anyone have ideas where to start with these??? thanx

[Warren96]

With the code numbers you have it must be a 1994 or 1995. When mine did that many codes at once, it was a loose ground. The last bolt on the intake manifold on the passenger side has a black wire that can have either a poor connection, or is loose. Remove it clean it with a wire brush and re-install it with a coating of grease. That will help keep it from coroding. Do the same thing to the thick red wire on the glow plug relay also. When it is knocking does it smoke ? Good luck and keep us informed.

[cheyenne1500]

When it is knocking does it smoke ? Good luck and keep us informed.

Big time smoke!!! Thick and black

[cheyenne1500]

K so...I've checked and cleaned all grounds in the engine bay, replaced the PMD with a relocator kit so that cant be a issue for a while and reset the computer. But the truck still runs like poo!! Eng knocks that sound like a air hammer against the block @ Full throttle or feathering pedal while crusing. Lots of black smoke. Low power. Shifting is kinda eratic. At a dead stop while in gear it surges/misses a little. So i checked the codes again and just code 12. No more codes generated after a 20 min of driving??? WTF. Just to add: when i've hooked up vac gauge, at idle the vac is not steady kinda fluctuates between 11.5 and 14. Any help!!!!

[rameye]

What year is your ride?? What model?
Are you DS4 or mechanical injection??
When or how did this start??

The more info...the more informed answers you'll get

[JohnC]

Have you done any work when the problem started? Could be crossed injector lines.

If not, loosen the injector lines one at a time until you find the one making the knock. Pull the injector and have it tested.

[cheyenne1500]

What year is your ride?? What model?
Are you DS4 or mechanical injection??
When or how did this start??

The more info...the more informed answers you'll get

95 1500 cheyenne. DS4 injection. S vin.

It all started a while back with a steady decrease in power over the coarse of a few months now its really bad. Just to add to the problem list...At full throttle....LOTS of black smoke, no downshifting and no power. I was thinking about the knocking problem...it only happens at certain engine loads....so it couldnt be mechanical...if it were a mechanical problem woulndt it knock all the time??

-Will loosen lines tomorrow to test injectors....
Just to say what i've replaced again:
-PMD with a relocater kit
-Fuel filer
-Lift pump
-Accel pedal sensor
-OPS
-Air filter
-Vacuum Lines

[cheyenne1500]

Ok so..i've just replaced the Waste gate solenoid. Truck runs alot smoother but still no power and no upshifting at full throttle. Now...2 codes come up that i havent seen since this started. 32 and 45....EGR faults. I guess replacing the Valve is next??

[Warren96]

Next you need a vacum gauge......

[cheyenne1500]

Next you need a vacum gauge......

What is the vac supposed to be at all the areas...EGR, waste gate, vac pump, etc...

[rameye]

dont rule out crapped up injectors...that was my folly!!!

do your egr rule-out...then try what Johnc was offering.

I agree that you would think if it was a mechanical problem it would bang all the time...but some things dont complain unless they are stressed/ under load.

crappy ignition of your fuel will make it bang as well as a host of other things including timing....checked that yet??

[Kenneth]

With the motor being an S vin, check your egr valve. Take the EGR valve off and apply 20" of vacuum. The valve should open and hold at 20". If the valve does not open and hold, or does not COMPLETELY close when the vacuum is relieved, then the valve is bad. You can try cleaning the valve, but you'll probably have to just repace it. What happens is carbon builds up in the valve cuasing it to stick open or not to close properly, causing rough idling and power loss because the motor is getting "dirty" exhaust air instead of clean intake air.

Another thing to do is to use "GM Top Engine Cleaner" in your motor. It works on both diesels and gasoline motors that use an EGR valve to clean carbon buildup in your intake, valves, etc. I used it just the other day in a 2003 mitsubishi lancer and it causes the motor to smoke, and you could see carbon buildup flakes and chunks coming out of the exhaust for a few minutes, but when we finished the motor ran a lot smoother. Talk to your local GM service tech and he should be able to help you out with the process. The auto dept here at the school I am attending recommends using a top engine cleaner when EGR problems arise, because EGRs usually fail because of carbon buildup in the valve. If there is buildup in the EGR valve what do you think it looks like in the cylinder valves, intake manifold, etc.?

[cheyenne1500]

K so ITS FIXED!!!! sorta. After trouble shooting just about everything...i neglected to look at the EGR valve itself. So.....i made a blocking plate for the EGR on the intake thinking this would tell me if the valve is good or not. Well...The truck runs better than it ever has!!! Power...I can here the turbo spool up real good now...no knocking or anything. BUT...can i just leave it like this???

[Warren96]

Even when they are working right, an EGR valve will have a negative affect on an engines performance. Sometimes I will even ''test'' my engine with the valve disabled to see if it makes it run worse.You may even notice your fuel mileage go up without it. Thats not to say that it should be removed, some states have severe penaltys for removing an emmision control device.

[cheyenne1500]

Even when they are working right, an EGR valve will have a negative affect on an engines performance. Sometimes I will even ''test'' my engine with the valve disabled to see if it makes it run worse.You may even notice your fuel mileage go up without it. Thats not to say that it should be removed, some states have severe penaltys for removing an emmision control device.


Here in ontario, canada the laws are pretty lax. Soo can it hurt the Eng in anyway if there is no egr??

[Warren96]

WOW, what a tough question!! That is something that will have to be answered by a member from a country that has no smog control laws. Lets put it this way, mine is a vin S and it wears all the emmisions equipment that it was built with.