Help please

[fasteddie]

I have a 2000 7.3L with 335,000 miles on it. My intake heater is not working. I changed the solenoid, but this was not the problem. I PCM is not telling the solenoid to turn on the heat grid. I changed the charged air intake manifold air temperature sensor but this did not work. There is one more air temp sensor in the air filter box. I figured i better start asking people for advise before i go any farther. I do not mind changing sensors considering the truck has 335,000 miles on it. Also, when it is cold out, I believe the wastegate closes to make the engine closes to make the engine warm up quicker. It seems to stay closed past warm up. The truck is pretty much powerless because i cant get boost while this wastegate is closed. It is only when it is cold out so it must be another temperature sensor. Can anyone help me out? any help is greatly appreciated.

thanks,
Eddie

 

[JLDickmon]

Mine's never worked, and I don't call it a great loss.
The only ones you would ever NEED to work, are on a glowplug-less engine, like a Cummins

Your Exhaust BackPressure Valve is what's closing to make that godawful hissing noise, and making your truck feel like it's popped a 'chute like a Top Fueler...

it will continue to cycle until the engine reaches operating temperature, long after it's throwing heat..

 

[Tail_Gunner]

.... Also, when it is cold out, I believe the wastegate closes to make the engine closes to make the engine warm up quicker. It seems to stay closed past warm up. The truck is pretty much powerless because i cant get boost while this wastegate is closed. It is only when it is cold out so it must be another temperature sensor. Can anyone help me out? any help is greatly appreciated.

thanks,
Eddie

You say wastegate, are you actually refering to the Exhaust Back Pressure Valve (EBPV)? The EBPV is the big butterfly valve on the turbo that closes off the exhaust pipe to help the warm up. The EBPV is operated by an actuator underneath the turbo in the turbo mounting pedestal. The wastegate is a little flapper valve inside the exhaust housing of the turbo that is controlled by a pressure actuator on top of the turbo.

Part of that EBPV system is a Ex. Back Press. Sensor (EBPS). There is a little tube that goes from the front of the right side exhaust manifold around to the front of the motor to the EPBS located near the HPOP reservoir. What this EBPS does is sense an increase of exhaust back pressure when the throttle is applied and the EBPV is still closed. The EBPS sends a signal to the PCM to open the EBPV. With the lack of power, it sounds to me like you're describing the EPBV staying closed.

Often times one of two things happens to cause this, either the tube to the EBPS gets clogged with carbon or a hole corrodes in it. In either case, the pressure increase is prevented from reaching the EBPS, so the signal to open the EBPV is never sent to the PCM.

A quick way of checking for this and can be a temp fix to return driveability is to unplug the EPBV actuator wire on the turbo pedestal. This will prevent the EBPV from closing. If this fixes your drivabilty problem, then you need to look for a problem with the EBPS or the tube that runs to it from the exhaust manifold.

 

[fasteddie]

Thanks! the only thing i am confused about is the fact that this problem only occurs in cold weather not in the summer time.

Thanks again,
eddie

 

[JLDickmon]

right.
the EBPV is akin to a "heat riser" on the ol' Man's '72 Caprice.
function is the same.. divert exhaust through the intake to warm it faster.

 

[dmd]

Thanks! the only thing i am confused about is the fact that this problem only occurs in cold weather not in the summer time.

Thanks again,
eddie

With that, it sound like it is probably working fine. EBPV is a winter warmer, dont need it when it is warm. Intake heater is
really just for smog reasons. Keep the truck from smoking too bad on cold starts, not much for warm up.

 

[fasteddie]

thanks to all. The tube tail gunner was talking about actually had a hole in it. I brazed it for a quick fix. Im going to make another one out of 5/16" brake line because a new one is fifty bucks. I still have an issue though. I am going to clean the sensor.

thanks,
again

 

[Tail_Gunner]

thanks to all. The tube tail gunner was talking about actually had a hole in it. I brazed it for a quick fix. Im going to make another one out of 5/16" brake line because a new one is fifty bucks. I still have an issue though. I am going to clean the sensor.

thanks,
again

Have you tried unplugging the wire connector to the turbo pedestal to see if your truck runs better?

 

[BJS]

your intake air heater not working is not a big deal but non functioning glow plugs are a bigger problem.

Many people remove the IAH on the 7.3 because you do not need it except in the most extreme cold situations.