Hesitation and Smoke

AK_Mike · **Joined:** Sat Aug 06, 2005 3:58 pm **Posts:** 12

When I floor the CRD to pass from highway speeds, I get a 3-4 second delay before the transmission downshifts. There appears to be no acceleration until the downshift. When the downshift occurs, there is a significant amount of soot coming out of the exhaust (enough that people behind me back off). Jeep runs great otherwise, and mileage is very good. I have successfully used the "smokem out" technique for tailgaters, but wonder if perhaps the PCM programming for downshift or perhaps the throttle position sensor is screwy. Anybody else experiencing this?

n3qik · **Posted:** Sat Aug 06, 2005 9:30 pm

Go find a parking lot some where and from a dead stop floor it. Do you still get that 3-4 second delay???

boxhead · **Joined:** Fri Jul 08, 2005 11:14 pm **Posts:** 186

Depends on the "highway speed." The turbo kicks in at ~1800 rpm, which is about 55 MPH. Anything below 1800 rpm and you're just experiencing turbo lag.

AK_Mike · **Joined:** Sat Aug 06, 2005 3:58 pm **Posts:** 12

From a stop or even from 50 mph if you floor it it accelerates smartly. It's the lane change from 65-70mph where this happens. It's not turbo lag; engine is at 2,000 rpm so boost should not be an issue. It's like the PCM is taking its good old time telling the tranny to downshift.

DogHog04 · **Posted:** Sat Aug 20, 2005 8:28 am

Ak:
I had the same soot thing last night. I was on the interstate with a slow gasser in front of me. When I floored it to pass a large cloud of black soot came billowing out! It looked like an old war movie with the smoke screen. My speed at acceleration was 60mph.

Bonehead · **Posted:** Sat Aug 20, 2005 1:37 pm

Hmm never had to floor mine , I just let the boost come up and let it stay in high gear seems to pull speed really good just like that. I try to keep it under 2800rpm because anything higher than that seem like a waste, basicly just using the torques sweet spot.

Hesitation and Smoke

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