- Joined
- Aug 26, 2008
- Messages
- 1,094
- Vehicle Year
- 1994, 2001
- Transmission
- Automatic
- My credo
- Failing is easy. Everyone can do it.
Been a while, but this is the place that got my old girl back on the road in the first place!
The truck has been running decent (about 20 mpg actually) however the last few days? It's got me a bit rattled.
Hitting around cruse speed, 55-70 is when this acts up the most. And seems to be when it's under a slight-moderate load. (have not tried to power it out of this) The truck will run fine--and then it will just quickly cut out with a rapid power loss--we are talking like kicking the key on/off for a split second. At first I figured "Crap...transmission is acting up", then I stopped panic mode LOL.. Figured out if the transmission was slipping? The engine would surge "UP" and not "DOWN"....likewise, if the transmission was dropping gears back and forth? Hitting overdrive to 3rd then back? Would take a great increase in RPM when it does so.
This happens so quickly the tach does not have a chance to react. Going by the engine "sound". It just acts like it cuts out quickly and then cuts back in with a slight shudder (as if one hits the brake and then gas rapidly) as it goes back to normal 'load'.
2 years ago we did major work on the engine, new heads...full injector service/cleaning...Most sensors have been replaced/checked/etc.. It's almost like someone turned the key 'off' and then 'on' within a second while going down the road. It has not thrown a code, CEL is still off. (will pull codes in a day or two and see if anything kicks up when the heat wave breaks..not working on it while it's mid 90's outside with high humidity)
First thought was TFI dropping spark for a split second....It's a newer module (about 2 years old). Other ideas, fuel pump cutting off/on? Pickup coil in the disty?... Maybe the FPR acting up? Looking for ideas so I can kick out a large number of tests on Sunday (next day off) and hopefully get my daily driver back up and running without fear of it dieing on the highway.
The other items of interest? Slightly hard to start when engine hot and up to temp, it does start...but we have a gassy smell for a few seconds after it starts. Hard accel it appears to have a slight 'chuggle' which I first thought was transmission related--but these A4LD's when they start to slip in gear? Normally crap outright and never recover.
Just looking for ideas!
Regards--
S-
The truck has been running decent (about 20 mpg actually) however the last few days? It's got me a bit rattled.
Hitting around cruse speed, 55-70 is when this acts up the most. And seems to be when it's under a slight-moderate load. (have not tried to power it out of this) The truck will run fine--and then it will just quickly cut out with a rapid power loss--we are talking like kicking the key on/off for a split second. At first I figured "Crap...transmission is acting up", then I stopped panic mode LOL.. Figured out if the transmission was slipping? The engine would surge "UP" and not "DOWN"....likewise, if the transmission was dropping gears back and forth? Hitting overdrive to 3rd then back? Would take a great increase in RPM when it does so.
This happens so quickly the tach does not have a chance to react. Going by the engine "sound". It just acts like it cuts out quickly and then cuts back in with a slight shudder (as if one hits the brake and then gas rapidly) as it goes back to normal 'load'.
2 years ago we did major work on the engine, new heads...full injector service/cleaning...Most sensors have been replaced/checked/etc.. It's almost like someone turned the key 'off' and then 'on' within a second while going down the road. It has not thrown a code, CEL is still off. (will pull codes in a day or two and see if anything kicks up when the heat wave breaks..not working on it while it's mid 90's outside with high humidity)
First thought was TFI dropping spark for a split second....It's a newer module (about 2 years old). Other ideas, fuel pump cutting off/on? Pickup coil in the disty?... Maybe the FPR acting up? Looking for ideas so I can kick out a large number of tests on Sunday (next day off) and hopefully get my daily driver back up and running without fear of it dieing on the highway.
The other items of interest? Slightly hard to start when engine hot and up to temp, it does start...but we have a gassy smell for a few seconds after it starts. Hard accel it appears to have a slight 'chuggle' which I first thought was transmission related--but these A4LD's when they start to slip in gear? Normally crap outright and never recover.
Just looking for ideas!
Regards--
S-