95 Bronco Trans Question

[miesk5]

Yo Pamm,
As Tiha advised and if you buy a new IAC, I suggest a Motorcraft unit from Rock Auto.
Then Check locally for a better price.

 

[Pamm]

You can let the spray sit. The valve is like a motor, the shaft that goes into the electircal part, if that get worn enough carbon gets into the electrical part. That side is hard to clean, you can't take it apart and clean it.

It is pretty common for them to stick, or idle funny until the computer re learns the position and adjusts, but if it does not go back to normal then the IAC is or was bad anyway and needs replaced.

I have had to clean them a couple times to make them better, but in the end I usually end up replacing them.
Not sure where price is now, but rock auto used to have them pretty cheap.

AutoZone told me a higher price

 

[Pamm]

I'm still doing things from here trying to get my trans from killing the motor when put in drive. Thanks for all the help everyone

 

[Pamm]

Yo Pamm,
As Tiha advised and if you buy a new IAC, I suggest a Motorcraft unit from Rock Auto.
Then Check locally for a better price.
View attachment 29381

I never have tried Rock Auto, I'll give it a try, thanks

 

[chrlsful]

no thing like that at Roc:

1995 FORD BRONCO 5.0L V8 Transmission-Automatic Parts | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

Car-parts

https://www.carparts.com/details/Ford/Bronco/Replacement/Idle_Control_Valve/1995/Eddie_Bauer/RF31320005.html?TID=gglpla&origin=&utm_source=google&utm_medium=pla&utm_campaign=12175888067&gclid=CjwKCAiA9tyQBhAIEiwA6tdCrLM5MFBZRuy-SwtnDhG3sF4j-hNhgEF-lNvADWVLJFm_n_IY2idXqBoCCS0QAvD_BwE&gclsrc=aw.ds

 

[L\Bronco]

That is a tough one, Kind of interesting that the trans shop is not able or willing to find anything else.

If it is killing the engine the torque convertor is locking up. Low fluid level can do that. But lets assume it is not low level or mechanical since 2 transmissions are doing the same thing. If you are not getting any codes to point you in the right direction then it is an electrical issue.

I have heard of people having problems with the wire harness, where it plugs into the trans on the rear pass side. Melted and corroded wires. Could be something there.
Also the MLPS, or neutral safety switch on the driver's side behind the shift linkage. I have heard of those filling with water and creating interesting problems.

But those are focused on shifting the trans and killing the engine.
If it is just an RPM change, how drastic is it? It may not even be related to the transmission any longer. Might have been fighting a couple different issues all along.

Hi, just want to add my 2 cents, To add to what Tiha said, it sounds exactly like the clutch in the torque converter is stuck on. The pressure is mechanically released from the clutch in man1 in a 4R70W which is why it works there. I would look at the P\Y wire that is in the transmission main bulkhead connector. It may be shorted to ground. That harness sometimes melts to the exhaust pipe or manifold (depending on routing)
If that wire is not shorted, it may be a pcm failure.
(You can cut the wire and see if your fault goes away as a diagnostic)
Hope that helps.
(Sorry if I'm butting into a conversation I don't want to step on toes.)

 

[Pamm]

Yo Pamm,
As Tiha advised and if you buy a new IAC, I suggest a Motorcraft unit from Rock Auto.
Then Check locally for a better price.
View attachment 29381

I had Autozone look and i had bought one lifetime warranty so I was able to get free. I put it on but still will not idle the same in drive/2nd as it does in 1st or rev. Usually dies in drive still. So now to look at what else it could be. By the way look on the pics how much Autozones price would have been...

 

[Tiha]

When you put it in gear. Into Drive. Does the truck lunge like it is trying to go? So if you had your foot off the brake would the truck take off down the road?

 

[L\Bronco]

Still sounds like the torque converter clutch is stuck on, (I'm sure that's what Tiha is getting at as well)
you could try unplugging the main connector at the transmission and see if it stops stalling.
It will be stuck in one gear with very high pressure, but it will rule out a few things. If it still stalls, the issue is likely in the valve body in the transmission. But if it doesn't stall unplugged, either the TCC control wire (pin 4 PPL\Yel) is shorted to ground, or the PCM is faulty.
Hope that helps.

 

[Pamm]

Hi, just want to add my 2 cents, To add to what Tiha said, it sounds exactly like the clutch in the torque converter is stuck on. The pressure is mechanically released from the clutch in man1 in a 4R70W which is why it works there. I would look at the P\Y wire that is in the transmission main bulkhead connector. It may be shorted to ground. That harness sometimes melts to the exhaust pipe or manifold (depending on routing)
If that wire is not shorted, it may be a pcm failure.
(You can cut the wire and see if your fault goes away as a diagnostic)
Hope that helps.
(Sorry if I'm butting into a conversation I don't want to step on toes.)

i have it as 950 idle , lil high but helps in drive problem. about 750 - 800 in rev and 1st. 2nd or drive usually kills motor but if not it's about 500 or 550 when all warm up it seems better

 

[Pamm]

You can let the spray sit. The valve is like a motor, the shaft that goes into the electircal part, if that get worn enough carbon gets into the electrical part. That side is hard to clean, you can't take it apart and clean it.

It is pretty common for them to stick, or idle funny until the computer re learns the position and adjusts, but if it does not go back to normal then the IAC is or was bad anyway and needs replaced.

I have had to clean them a couple times to make them better, but in the end I usually end up replacing them.
Not sure where price is now, but rock auto used to have them pretty cheap.

I did replace it with a new one. no different

 

[miesk5]

Yo Pam,
Did you spray in the throttle body port where the IAC sits in?

 

[Motech]

Two things commonly cause this symptom:

1. Vehicle Speed Sensor: This is the two-wire sensor in the differential housing. Sensor becomes very sensitive and will spike when driveshaft engages differential gears, sending a high speed signal to PCM causing shutdown.
2. ATF in the main transmission control connector: This will cause ATC circuits to short, often engaging the Torwque Converter Lockup circuit causing a loaded stall in gear.

First try disconnecting VSS sensor at differential. If symptom goes away, there it is.
If no joy there, unplug ATC harness from transmission. If connector is dripping ATF, replace transmission controls sub harness (inside pan)

 

[Pamm]

Yo Pam,
Did you spray in the throttle body port where the IAC sits in?

Yes I sprayed it before I replace with a new IAC. I did replace it with a new one. no different

 

[Pamm]

Two things commonly cause this symptom:

1. Vehicle Speed Sensor: This is the two-wire sensor in the differential housing. Sensor becomes very sensitive and will spike when driveshaft engages differential gears, sending a high speed signal to PCM causing shutdown.
2. ATF in the main transmission control connector: This will cause ATC circuits to short, often engaging the Torwque Converter Lockup circuit causing a loaded stall in gear.

First try disconnecting VSS sensor at differential. If symptom goes away, there it is.
If no joy there, unplug ATC harness from transmission. If connector is dripping ATF, replace transmission controls sub harness (inside pan)

Ok sorry but where is the Vehicle Speed Sensor located and the ATC ? The shop put a new switch on the left of transmission what ever that is.

 

[Pamm]

When you put it in gear. Into Drive. Does the truck lunge like it is trying to go? So if you had your foot off the brake would the truck take off down the road?

No, it jumps and dies instant, unless in rev or 1st until rolling in 1st then i can shirt into drive

 

[L\Bronco]

Sorry Pamm, have you tried unplugging the main trans connector and see if it still dies in D? (I may have missed it in the thread)

 

[Tiha]

That is actually a great idea. Help to hopefully narrow it down to electrical or mechanical.

Pass. Side reaf of trans, behind heat shield. The truck should still move in forward and reverse with this unplugged.

 

[Motech]

Ok sorry but where is the Vehicle Speed Sensor located and the ATC ? The shop put a new switch on the left of transmission what ever that is.

Sorry, I guess it wasn't clear:

"Vehicle Speed Sensor: This is the two-wire sensor in the differential housing"
Or more specifically, the two-wire sensor that mounts in the top of your rear end, like this here:





ATC = Automatic Transmission Controls, the multi-wire connector on side of transmission that @L\Bronco referenced after you asked.

Any luck yet?

 

[Pamm]

Sorry Pamm, have you tried unplugging the main trans connector and see if it still dies in D? (I may have missed it in the thread)

I am just getting back on it again this week. Been out of state working some.