Surging downhill @ 50mph?

TYTILIDIE

TYTILIDIE

METH HEAD
When I go down hill wheather its a little hill or big, between 45-55 mph, my RPMs go from 1500-2300. i.e., its going in and out of third and fourth gear. Is this normal? My last trans did this also but it was not nearly as drastic. It also didnt do it as long as I had it til I started having this wierd idle problem. I keep getting IAC code but am not sure why. On DM its working fine. Dont knwo if that has something to do with it or not. Any ideas?
 
TYTILIDIE

TYTILIDIE

METH HEAD
Re: Surging downhill @ 50mph?

Hey thaks, I appreciate it. It does kinda sound like me. My shifts actually kinda suck though. Im definately going to look into this.
 
George Blake

George Blake

DONATING MEMBER
Re: Surging downhill @ 50mph?

OK. The reason I'm asking is we need to see if it's the converter locking and unlocking or if it's truly going in and out of 4th.
You trans should not downshift out of 4th until about 42 mph. 45 mph is too high to downshift out of 4th without you smashing the throttle.
 
ircwet

ircwet

New member
Re: Surging downhill @ 50mph?

Hmmmm is there a time when TYTILIDIE doesnt SMASH the throttle !!! HAHAHAH J/K
 
TYTILIDIE

TYTILIDIE

METH HEAD
Re: Surging downhill @ 50mph?

Actually, this is not even on the throttle. Its usually just coasting or very lightly on the throttle. I cant run DM today cause iM hooking up my WB and have the truck in pieces. Although it will be back together this evening Im going cruising/racing, and dont wnat to open up the laptop. I will definately do this first thing in the mrning though. Ive just had a super long and hard week and the thought of opening my laptop doesnt appeal to me. However, theres always that chance that I will. It just depends on what time the wife gets home from work I guess and if I can get the wiring for the WB done. Ill be back later.
 
ZavzTy547

ZavzTy547

Senior Member
Re: Surging downhill @ 50mph?

TYTILIDIE said:
Actually, this is not even on the throttle. Its usually just coasting or very lightly on the throttle. I cant run DM today cause iM hooking up my WB and have the truck in pieces. Although it will be back together this evening Im going cruising/racing, and dont wnat to open up the laptop. I will definately do this first thing in the mrning though. Ive just had a super long and hard week and the thought of opening my laptop doesnt appeal to me. However, theres always that chance that I will. It just depends on what time the wife gets home from work I guess and if I can get the wiring for the WB done. Ill be back later.
Click to expand...

Mine surges (between 2000-2500 when it's coasting downhill as well but only when the car is warming up. It started doing this after I installed the 2800 TC.
 
George Blake

George Blake

DONATING MEMBER
Re: Surging downhill @ 50mph?

There was an issue with the load being seen by the map sensor in certain situations caused by going to a different stall(depending on converter). This isn't the lockup issue necessarily but may take some tweaking of the table where the rpm/load/injector pulsewidth factor(I think this is it) related to closed throttle. Deceleration enleanment I think it's called. This isn't a TV issue from what I've seen here.
 
TYTILIDIE

TYTILIDIE

METH HEAD
Re: Surging downhill @ 50mph?

Ooh, I just went to a 3K. My other TC was a 2500. Before I went to 2500, I never had this happen. I can say that its really noticeable now. Im going to get some DM runs here soon.
 
cloneman315

cloneman315

Active member
Re: Surging downhill @ 50mph?

mine had a lean spot around that rpm and it did that ,we added fuel and it fixed it
 
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