97 powerstroke questions

[jkh]

my brother has a 97 ford powerstroke with a cold weather problem. when he starts it in the cold(even if it has been plugged in),when he tries to go,he can get to about 20 mph but thats it and it is blowing black smoke and sounds muffled. if he leaves it warm up 1/2 hour then it is fine. he says there is a "Flapper valve" on the turbo which he says is stuck closed. could this be the waste gate and might it be stuck open instead of closed and dumping all his boost? i don't know much about fords so i'm hoping someone out there can help us. Thanks.

one other thing. last week he had a situation where after puling about 7000lbs. for a while he unhooked the trailer then when he stopped and tried to put it in reverse it killed the engine. he could go directly to park and then reverse and it was fine but not drive to reverse , any ideas on this. thanks again.

jerry

 

[ROADWARRIOR]

I'm not sure, but I've read that some years had a flapper that was for aiding cold weather warm ups. I think I read about it being controlled through aftermarket devices as an exhaust brake. It might have been on Diesel Dynamics website. If that is the case, being stuck closed would definitely cause major black smoke and no power.



Dan

 

[CGriffith]

I can't say if the 97s had the valve in the exhaust but I know the 99 and up 7. 3s did. They are used to help warm the engine in cold weather but can be used as cheap exhaust brake with marginal results. The trucks I have been around you can hear the valve open and close if you are standing near the exhaust while they warming up. There will be a noticeably loud whoosh sound when the valve is closed at idle. From what I have heard the computer should engage the valve if the water temp is below 140F and the truck has idled for any amount of time. I have driven my truck with the exhaust brake engaged -no speed and lots of smoke was the definite result if you stomped on it at all

It sounds to me like the truck has computer problems.

Did the truck lurch when it died or did it act like you just turned it off? My guess if the truck lurched at all is the converter was still locked up which will give the same results as sidestepping the clutch on a manual. Could be the transmission dieing or computer problems.

Good luck,

Griff

 

[lmills]

97's had them also. they are called exhaust back pressure valves.

 

[DPelletier]

I had a '96 PSD that did the same thing. I complained and the dealer replaced a whack of parts, but it never was fixed. the truck wouldn't rev past maybe 1700 RPM no matter how hard you stepped on it when it was cold and I figured (perhaps erroneously) that even without the turbo (like an old 6. 9), it should at least rev out. Sorry I can't help.



Dave

 

[jkh]

if the t. c. was still locked up wouldn't the truck have died when he came to stop?

 

[lmills]

if the converter is locked it will stall the motor when the truck is sitting still in any gear

 

[bmoeller]

Sounds like the back pressure valve after the turbo is stuck shut, or close to it.



Yes, Western Diesel has a box to control the valve manually so it can be used as an exhaust brake.



http://westerndiesel.com/performance-diesel/powerstroke/powerstroke-turbo-brake.html