themorb
Getting the Wheeling Fever
Reged: 09/21/07
Posts: 39
Loc: Victoria, BC, Canada
|
EGR / TPS
01/26/09 04:08 PM
|
|
|
Well I discovered yesterday that the little hose which controls my EGR valve has *worn through* by rubbing on the rough surface of the braided air hose from the turbo. Almost unbelievable, but I guess vibration will do that over time. So I wondered how long I had been driving with no EGR. Also, I have a pyrometer so I wondered how fixing the EGR would affect my EGT's. I bought two 4-foot sections of vacuum hose and a coupler and ran them in through my window so I could manually control the EGR while driving.
I started with a finger on the vacuum hose to see under what conditions the car wanted to activate the EGR. Seemed to be a vacuum all the time! Acceleration, idle, coasting... So I thought maybe it was always supposed to be open when the engine is warm. So at the next red light I hooked the two hoses together. No change in engine sound. Light turned green, pressed the gas, HUUUUUUGE cloud of black smoke, BIG rattle from the engine, and barely moved forward. I quickly pulled the hoses apart, engine went back to normal and drove off.
I got to the highway and was going ~90 coasting down a slight hill. EGT's were around 300 celsius. Connected the EGR, and felt myself having to press harder on the gas to keep it at speed. EGT's climbed to 450!!!! The road levelled out flat, and they climbed close to 600!!! (I never ever ever let it exceed 700, even when towing a trailer up a hill...)
So now I'm trying to figure out what signal controls the EGR solenoid. I think it is the TPS. I fiddled with the TPS way back when I first got my Paj, and it didn't seem to have any effect. So I bet my EGR was never working, and I probably left the TPS adjusted wrong.
In any case, I have activated the EGR under all possible conditions - idle, acceleration, coasting, up hills, etc. and it always seems to make the engine run worse, and EGT's higher. So maybe it reduces a bit of emission down hills but for what it's worth, I think I'll just leave it disconnected!
The only positive thing is that opening the EGR and stomping on the pedal makes a reeeeal nice black cloud to ward off tailgaters :)
--------------------
1991 JDM Pajero Exceed
|
|
Previous
Index
Next
Flat
Edit
Reply
Quote
