540i Surge on stratup; Idle wont settle down

[MBXB]

540i Surge on stratup; Idle wont settle down

OK here goes..

I just got my car back from my indy. He swapped in a rebuilt trans, water pumps (main and aux),
Before I left, I confirmed with him that ALL fluids and torques were double checked and good.
ONe thing I noticed when I left was the RPMS would surge up to 2K on startup then setle back down to 650-700 RPM.
In rush hour traffic it ran OK , shifts were good, idle was good.
After about 25-30 miles of driving I noticed it was not shifting out of 1st. RPMS would go to 2500-3000 so I backed off.
Figuring it was just the adaptive program, I pulled over and shut down, then dired it up again. Same thing after driving 1/2 a mile or so.
I limped home and parked it.
Disconnected the battery and left it overnight.
Checked and DEOXed the MAF connector just in case.
Fire it up this morning and the same idle surge.
Now it's throwing a Engine Check Light AND a Trans Code.
Idles only down to 1000; if I shut down and restart sometimes it's 2000.

My Peake reader says 51
No 51 Code on the code list for a 94 540iA

Any suggestions as to where to start?

Thanks in advance.

Ramon

[MBXB]

Yup ryan, I spent Saturday sifting thru the archives, Bruno's site and Bentley's. After reading thru the BMW transmission diagram it could be any of the sensors that goober touched or disconnected.

I'm going back to square one checking all of them. My biggest fear is he didn't install the trans properly and I fried it driving home.

[ryan roopnarine]

since you are just fishing for answers here--the check engine light in conjunction with the trans pg sounds like it is something other than the trans doing it. try making sure that when the car surges, that the throttle plate is really returning to full shut by pushing it shut with your hand. clean the connector on the tps,, and maybe lube the throttle body.

[MBXB]

It turned out to be the TPS.
They 'cleaned' the engine compartment and got moisture into the switch.
They replaced it for free.

since you are just fishing for answers here--the check engine light in conjunction with the trans pg sounds like it is something other than the trans doing it. try making sure that when the car surges, that the throttle plate is really returning to full shut by pushing it shut with your hand. clean the connector on the tps,, and maybe lube the throttle body.

[ryan roopnarine]

that's good.

[genphreak]

Dealing with the same trouble here on a 5HP18 in an M50 525i. I bet your trouble is Trans program 100 (speed sensor or clutch problems). I hope its not the clutches, but if she still goes into Limp mode after an EGS reset (or an unplug of the trans computer), that'd be it...

The trouble mine first displayed was a desire (when held in second or third) not to allow the engine past 2000-4,000rpm depending on how long you waited... it'd just get to speed in its own time but then invariably give up at 3000-4000 rpm (no real power once you chose to hold the gear). Otherwise it behaved fine except the idle was a little eratic (sometimes). Then one day I held the gear regardless of the bad running and KABOOM 3rd gear slammed in spinning the rear wheels (engine at 3500rpm) a little and TRANS PROGRAM was showing on the dash.

Haven't been able to get it going again. The reset stops the TRANS PROGRAM until it gets into second gear and then the whole car will slow down like the thottle was backed off fast, and then KABOOM 'Trans program'. With a 5HP18 the tranny's speed sensors are all inside the trans body, but judging from the oil the PO had in it, it was the clutches anywhow... oh crumbs... what to do now...

[whiskychaser]

Dealing with the same trouble here on a 5HP18 in an M50 525i. I bet your trouble is Trans program 100 (speed sensor or clutch problems). I hope its not the clutches, but if she still goes into Limp mode after an EGS reset (or an unplug of the trans computer), that'd be it...

The trouble mine first displayed was a desire (when held in second or third) not to allow the engine past 2000-4,000rpm depending on how long you waited... it'd just get to speed in its own time but then invariably give up at 3000-4000 rpm (no real power once you chose to hold the gear). Otherwise it behaved fine except the idle was a little eratic (sometimes). Then one day I held the gear regardless of the bad running and KABOOM 3rd gear slammed in spinning the rear wheels (engine at 3500rpm) a little and TRANS PROGRAM was showing on the dash.

Haven't been able to get it going again. The reset stops the TRANS PROGRAM until it gets into second gear and then the whole car will slow down like the thottle was backed off fast, and then KABOOM 'Trans program'. With a 5HP18 the tranny's speed sensors are all inside the trans body, but judging from the oil the PO had in it, it was the clutches anywhow... oh crumbs... what to do now...

Would think you would get codes 16 or 42 if its a speed sensor but you can check the resistances for the sensors and valves at the epu end. Mine was so sluggish it was like driving a manual with a slipping clutch. Dropped the pan and found loads of swarf on the magnets-time for a a change. Put new sensors in the 'new' box and its been fine since.

[genphreak]

Would think you would get codes 16 or 42 if its a speed sensor but you can check the resistances for the sensors and valves at the epu end. Mine was so sluggish it was like driving a manual with a slipping clutch. Dropped the pan and found loads of swarf on the magnets-time for a a change. Put new sensors in the 'new' box and its been fine since.

Yea, maybe mine is so old that it only throws a 100. The codes get better as the years progress... this is a bad one as it feles like the engine is bogging. Isuspect it is actually the trans passing all kinds of confisuion ot the ECU.

[whiskychaser]

Yea, maybe mine is so old that it only throws a 100. The codes get better as the years progress... this is a bad one as it feles like the engine is bogging. Isuspect it is actually the trans passing all kinds of confisuion ot the ECU.

There are lots of 5HP18s but they are not interchangeable. They changed the box in Sep 1992 so after that it doesnt fit mine which is Feb 1992. Best way to tell is check the BMW number on the plate. Mine is 1056000071 which is same as 075. But an 083 def wont fit. I still have the valves and sensors from the old one and can let you have resistances if that would help

[genphreak]

There are lots of 5HP18s but they are not interchangeable. They changed the box in Sep 1992 so after that it doesnt fit mine which is Feb 1992. Best way to tell is check the BMW number on the plate. Mine is 1056000071 which is same as 075. But an 083 def wont fit. I still have the valves and sensors from the old one and can let you have resistances if that would help

Thanks, WC- that's good to know. there are those listed on the bmwe34.net trans program page too.. I'd love to know your values as I am testing mine tomorrow... sharing is good, so if you can do that of course I'll post mine after that. thanks in advance- Nick