Archived Truck Building Boost at Idle

[seagrave2001]

I was getting some lunch and when i came to a stop light my truck sounded really weird... It sounded like an exhaust brake was closing up my exhaust and the truck wanted to pull me through the light... So i put it in neutral and the rpms jumped up a couple hundered rpms and returned to normal... Then when I put it back in drive it stalled right away... So i restarted it & put it in drive again and had to give it fuel so it wouldn't stall. . then when i got going it sounded like the engine had a load on it... Once I got going it shifted fine & ran fine until I got to the parking lot and pulled into my spot where it did the exact same thing and my pyro was going up to around 600 and my boost was up around 5lbs and the engine sounded like it had a load on it so i took it out of gear and shut it off and found no codes set... What could be causing this? Could the wastegate closing cause something like that to happen? And is it safe to drive it like that?

 

[seagrave2001]

think it might be the transmission because it doesn't do it until you put it in gear. . also the fluid smells burnt... .

 

[Scrappy]

the wastegate is closed until you reach x amount of boost. Sounds like something is trying to seize in the transmission.

 

[B.G. Smith]

think it might be the transmission because it doesn't do it until you put it in gear. . also the fluid smells burnt... .

Sounds like the torque converter clutch is trying to lock up??? bg

 

[Stmpplr]

Doesn't this sound more like it is related to idle speed? Out of gear and rpm's increase, then drop, make me think along lines of throlle linkage sticking and then letting go, back to normal position. Not sure but wouldn't the increased rpm's start to make boost also?

 

[Diesel Nut]

How about trying to reset the TPS? Maybe the throttle position sensor lost its calibration and is giving just a little too much throttle to the computer? I don't see one of these rolling computers having throttles "stick" so much as I can see one getting just a touch out of wack. Heck, everything you do in that thing except steering has some sort of computer atached . Maybe?

 

[Scrappy]

the engine has to be under load to develop boost, revving it from idle won't make boost unless you are overfueled. I can run down the road @ 50 mph and 0 boost @ 1500 rpms in 6th.

 

[seagrave2001]

Well guys I finally found out what was wrong w/ my truck... I got it to a trusted garage and they said it needs a new torque converter, a few of the bands are messed up and the drum is scored pretty good so i will be getting a whole new rebuilt transmission. . The bad part is where I got the truck said & showed me the bill where the transmission was just rebuilt... but they must of did a half ***** job and just patched it to get it off the lot... won't be going to him again... I’m just glad i got the 36 month extended power train warranty... .

 

[p-Bar]

While your at it beef up that trans

 

[SDrake]

P-Bar is telling you something that I strongly agree with. If I had known how much better my truck would drive with a stronger torque converter I would have had it rebuilt a long time ago. My 94 with 230K miles started to leaking and at that milage I knew the transmission was on borrowed time so I jumped at the chance to upgrade in anticipation that i would do some engine power mods and have a little fun after driving it stock for 11 years. Did several things but the triple clutch torque converter with a lower stall speed just makes the truck move out even when it is not in lockup, and when lockup occurs it is smooth, strong, and quick. The whole thing just feels like the power is getting to the ground. I have installed Westach gauges and have been enjoying driving the stock engine while I get aquainted with the readings. Tooling around town is a real pleasure with the tight transmission and the Beilstein shocks.



A #10 plate and 3K GSK will go in next. I concurr, beef up the transmission. Even if you are not planning on mods.

 

[MMeier]

Yes, definitely go the upgraded route!! You won't believe the difference an aftermarket converter and properly done up shift kit can do for a automatic, granted its still an automatic, but.....