rev limit in park

[kickeralpine]

if that was bad wouldnt the car start in drive if so it doesnt it will only start in p@n

 

[Racer X]

not necessarily. In addition to being a switch, its also a lever position sensor for the EEC. If it's out of spec, the EEC could think it's in gear when it's not, and remove the rev limiter thats in place in park and neutral. If you had access to a scan tool like the SnapOn Scanner, you could do a real time scan and see if this is the case or not.

 

[kickeralpine]

ok thanks for the help ill have a guy i know scan it for me and ill let ya know what i find. someone did change the tranny in the car so i think you may be right.

 

[shoebilly]

if that was bad wouldnt the car start in drive if so it doesnt it will only start in p@n

Never rev high without a load on the engine! THIS IS THE RULE.

 

[Racer X]

Never rev high without a load on the engine! THIS IS THE RULE.

Huh?

I'm pretty sure he was asking if a failing MLP would allow him to start the car in a gear, rather than P/N, and then further explaining that the car will only start in P/N. I have been known to be wrong before, but that's what I got out of it.

 

[kickeralpine]

racer x your right shobilly has been bashing me sense i posted this. i know not to rev in park but checking the secondarys i seen it was reving past 4k and rev limit hit at 7k in park.

 

[Shoaz]

The start enable and gear select circuits are separate in the MLP, so a circuit failure in the gear select wouldn't necessarily show up as being able to start in D.

The MLPs are very easy to swap out. If he's got two ATXs he could just swap the MLPs between them and see whether the so-called "problem" moves with the MLP or not.

 

[kickeralpine]

where is the mlp at on top of trans and i do have another 94 atx complete im using for parts tranny died .

 

[SASHO91]

this is kinda off topic.. but i figured i'd ask this here...
ive noticed on newer 96' up vehicles... some can rev to the actual engine limiter... for instance, my 96' bronco did it.. a buddies 01-02 chevy 1500 does it.... just to name a couple...

is this problem mainly sho specific? i mean i know other vehicles do it too but...

on with the thread.... well after that gets answered....

 

[SHOtimer]

I think it might be a Ford thing...I have never noticed it in GM cars.

Doug

 

[Axianator]

where is the mlp at on top of trans and i do have another 94 atx complete im using for parts tranny died .

As Eric and Hamal have both noted, a malfunctioning MLP (or Transmission Range) sensor can cause the symptoms that you have described and will usually set a 634 (TR sensor out of range) or 654 (TR sensor not in park) DTC. The sensor itself is located on the driver's-side of the tranny where the shift linkage connects to the top of the bellhousing.

Have you pulled your codes yet?

ive noticed on newer 96' up vehicles... some can rev to the actual engine limiter... for instance, my 96' bronco did it.. a buddies 01-02 chevy 1500 does it.... just to name a couple...

is this problem mainly sho specific? i mean i know other vehicles do it too but...

Unfortunately, engine rev limiter programming can differ on cars of the same vintage or model line. Case in point would be the '93 H3Zx and '94-'95 D4U1 ATX calibrations, where the '93 H3Zx sees a slightly different limiter than the newer '94-'95 D4U1.

 

[kickeralpine]

yes pulled codes and was 522 mlp was bad replaced problem solved. thanks to all that helped now only revs to 4000k thanks guys. big thanks to racer x he was the one who pointed me in the right direction

 

[Racer X]

yes pulled codes and was 522 mlp was bad replaced problem solved. thanks to all that helped now only revs to 4000k thanks guys. big thanks to racer x he was the one who pointed me in the right direction

No problemo, glad to help.