[Bintang Besar]

I have a '95 Eddie Bower 351 c.i. Bronco. Bought it twenty years ago @ 40k miles. It now tops 160k miles. It has been a great truck. I'm a stickler with the FORD Maintenance Schedule. Haven't missed a check up of any kind for twenty years.

Late last year the following symptoms occurred:

Rocking along at 70 mph on a flat highway when the engine "stumbled" but only for a heartbeat. However, the sensation was like hitting a pot-hole at 70.

The tachometer was steady at 2,000 rpm when the stumble occurred. Tachometer instantly bounced down to 1,000 for an instant and jumped straight back up to 2,000.

The engine did not stall and it continued without a hint of a stumble for a few days and the symptom repeated itself.
These repeats came about once every week or so. It never happened at anything except at highway speed and it never shut down.

The techs at my repair garage didn't have a clue. They advised that they were somewhat unarmed as the '95 Bronco was born a few years too early to enjoy modern diagnostics equipment. They acknowledged that diagnosing the "gremlin" would be difficult and that, in all likelihood, it would have to fail while it was at their shop. They drove it over a week's time in all kinds of conditions but it never stumbled; not even once.

Their assessment was that the throttle positioning sensor was failing but they couldn't prove it. I let them replace it for $400. I picked it up and almost made two miles when the engine stumbled at 40 mph and shut down in traffic. I returned it to the shop the next morning and it stumbled again in an intersection @ +/- 5 mph but did not shut down.

At this point the management advised that they didn't have the "old car guys" required to diagnose my problem. Also, that the FORD dealership also didn't have the tech's either. I am on the lookout for that old car guy.

I would appreciate any thoughts you might have. My Bronco can't be trusted so it spends most of the time making short hops and avoiding highways.

Hope someone can give me a few leads. I can answer any and all questions about the truck's history. I have all of the work history.

Red Dog

 

[sackman9975]

Where is your location?

I've been driving Bronco's 30 years. The last 20 years has been two 1995s.

Driving at 70 and your tach drops from 2000 to 1000 you say?

During this event, did the truck instantly slow down? At this speed, the torque converter is LOCKED. So that would mean to me something driveline. I don't believe a sensor would cause this. This would explain the shutdown at 40 but not at the intersection. Because at 40 the convertor is LOCKED. But isn't at 5mph.

You need to be careful. Sounds to me like you have a broken spider gear or broken pinion or ring and the piece is getting caught between the ring gear and pinion gear during rotation.

Time to pull the rear diff cover and have a look. I'm betting I'm hitting the nail on the head here.

 

[fodder]

I've seen that happen when fuses (EFI related) aren't well seated. Small bumps in the road cause them to lose the signal momentarily, and the RPMs drop with a feeling of the engine cutting out.

 

[miesk5]

Yo Red Dog,
Welcome!
E4OD Transmission Control Indicator Light (TCIL) is a LED with an overdrive on/off switch at end of the Transmission shifter stalk; flashing OD light is an indication of a transmission related trouble code in the Powertrain Control Module (PCM).
The transmission control switch is a momentary contact switch. When the switch is pressed, a signal is sent to the powertrain control module (PCM) (12A650). The powertrain control module then energizes the transmission control indicator lamp and the coast clutch solenoid, applying the coast clutch to provide engine braking and cancels fourth gear operation; does it cause the lamp to glow?
The TCIL indicates overdrive cancel mode activated (lamp on), electronic pressure control circuit shorted or monitored sensor failure (lamp flashing).


Try a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19 @ Code Reader

PCM stores the Self-Test program in permanent memory. When activated, Self-Test checks the EEC system by testing memory integrity and processing capability, and verifies that various sensors and actuators are connected and operating properly.

The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test. Run it around to heat the engine up and shift thru all gears including Reverse. Make sure A/C is off and transmission is in Park (automatic); or in Neutral for a Manual & release clutch. Then turn off engine, all accessories/lights (close driver's door) , etc.

Do KOEO test First. Post Code(s) here according to KOEO & KOER.
A helper can assist you by counting the codes. Some use their smart phones to record them.

BEWARE OF FAN, BELTS, PULLEYS, HOT HOSES, IGNITION HIGH TENSION WIRES, AND ENGINE COMPONENTS

Or ask local mom and dad parts stores if they will test it for you.
Or purchase a coder reader such as Equus 3145 Innova OBD I Code Reader for Ford EEC IV Engines at Walmart & most parts stores.

●
ASAP, find out if speed control recall work, if equipped was completed. If you still have concerns about Recalls, please contact the Ford Customer Relationship Center:
US: 800-392-3673 | CA: 800-565-3673
Note: 3673 spells "FORD" on phone keys
For the hearing- or speech-impaired: Please contact the Telecommunication Relay Service by dialing 71
"Summary: ON CERTAIN PICKUP TRUCKS, PASSENGER VEHICLES, SPORT UTILITY VEHICLES, AND MOTOR HOMES CHASSIS, THE SPEED CONTROL DEACTIVATION SWITCH MAY, UNDER CERTAIN CONDITIONS, LEAK INTERNALLY AND THEN OVERHEAT, SMOKE, OR BURN. THIS COULD RESULT IN AN UNDERHOOD FIRE."
See this guide by jowens1126 to confirm recall status @ 93 & 94-96 Cruise Control Recalls Repair
Note that the 93 recall is different than 94-96.

1995 Bronco Dealer Brochure @ 1995 Ford Bronco

1995 Bronco Drivetrain, Powertrain Service Manual - Google Drive
&
1995 Bronco Chassis, Service Manual - Google Drive
To switch between folder list & grid views, click the button to the right of the "DOWNLOAD ALL" button in the upper right corner of the window) by HawkDriver

Haynes Red Manual for 80-95 Bronco & F Series @ Hanes guide 80-96 bko f series.pdf via BroncMom

For any Bronco questions or to chat about it's planned modifications or build, it's better to post each seperately in Noobie Bronco Tech Questions. Flame free zone. This will get more attention and you can build up your post count to get into other sections such as Bronco and Ford Parts/Accessories (50 non-padded posts required to participate, due to scammers who preyed on our members).

Our Forum FAQs includes for example, How to:Use Search, Post pics and more tips

See How to add your Signature @ Bronco Forum - Full Size Ford Bronco Forum by BigBlue 94

➡ Baba Looey's Favorite FSB Links (lots and lots of tech links)
... Includes such as, How do I fix my back window?

Take time to participate in our next Full-Size of the Month & later in the year, Full-Size of the Year Contest @ Voting
You will get ideas by those competing.
Prizes are awarded to the winner!; a full spread in Bronco Driver Magazine is the top prize, in addition to a years subscription, once the article is submitted; and a years worth of premium FSB membership.
Al

 

[BigBlue 94]

During this event, did the truck instantly slow down? At this speed, the torque converter is LOCKED. So that would mean to me something driveline. I don't believe a sensor would cause this. This would explain the shutdown at 40 but not at the intersection. Because at 40 the convertor is LOCKED. But isn't at 5mph.

The converter is NOT always locked above 40 in an e4od. When going down hill it usually will unlock, then re-lock when the throttle is opened more, even at 70mph. Thats why the toggle switch mod to keep it locked was implemented by many guys towing with one.

OP,
As you have found, most "mechanics" these days are just techies who have zero experience troubleshooting an engine. All they know how to do is plug in a device and swap parts.

Im going to second the rear diff inspection. Thats where the computer gets its raw speed signal from, which not only affects the engine tune, but also the transmission shifting and locking.

 

[sackman9975]

The converter is NOT always locked above 40 in an e4od. When going down hill it usually will unlock, then re-lock when the throttle is opened more, even at 70mph. Thats why the toggle switch mod to keep it locked was implemented by many guys towing with one.

So school me on what unlocks the converter?
First I've heard of this. The brakes do unlock the converter, so if you're braking down the hill I can see this, but what else signals the converter to unlock? As far as I know, there isn't anything to unlock the converter other than gear change or braking.

Also, as long as your in 3rd or OD at 40 the converter is locked when at operating temperature. If you're in 2nd, it won't be. Assuming 40 is normal driving, it should of been locked.

 

[BigBlue 94]

So school me on what unlocks the converter?
First I've heard of this. The brakes do unlock the converter, so if you're braking down the hill I can see this, but what else signals the converter to unlock? As far as I know, there isn't anything to unlock the converter other than gear change or braking.

Also, as long as your in 3rd or OD at 40 the converter is locked when at operating temperature. If you're in 2nd, it won't be. Assuming 40 is normal driving, it should of been locked.

I cant really say, im just sorta repeating what I read many many years ago. I dont know hardly anything other than the basics of an automatic.

The converter locks when its circuit is grounded. The wire that sends this ground signal is purple w/ yellow stripe. The mod had you splice into this wire, with a wire going to the output of a toggle switch. The normally 12v input of the switch was hooked to ground. Flipping the switch would keep the converter locked until the switch was flipped off. When off, the converter functioned as intended.

The supposed reason for this was guys hauling a heavy load in hill country. When going down hill, and the throttle was closed slightly, the converter would unlock. Then it would have to re-lock when the throttle was opened for the next ascent. Continuous repetition of this caused heat to build and the trans to fail.

 

[packagerjr]

Is this thread better served in the Noobie or 80-96 forums?

 

[jermil01]

good call @packagerjr, I'm moving it over..

 

[reds]

I had a very similar issue with my 96. I too bought mine 22 years ago with just under 60,000 miles. Maintained religiously and still doing so to this day. At first it would occur on occasion but do fine for a week or so before happening more frequently. Mine would drop rpms briskly like it was going to die but would quickly recover. Turned out to be a bad ignition control module. Replaced it and no further issues. Just a possibility to look at. Good luck.

 

[Bintang Besar]

Where is your location?

I've been driving Bronco's 30 years. The last 20 years has been two 1995s.

Driving at 70 and your tach drops from 2000 to 1000 you say?

During this event, did the truck instantly slow down? At this speed, the torque converter is LOCKED. So that would mean to me something driveline. I don't believe a sensor would cause this. This would explain the shutdown at 40 but not at the intersection. Because at 40 the convertor is LOCKED. But isn't at 5mph.

You need to be careful. Sounds to me like you have a broken spider gear or broken pinion or ring and the piece is getting caught between the ring gear and pinion gear during rotation.

Time to pull the rear diff cover and have a look. I'm betting I'm hitting the nail on the head here.

Where is your location?

I've been driving Bronco's 30 years. The last 20 years has been two 1995s.

Driving at 70 and your tach drops from 2000 to 1000 you say?

During this event, did the truck instantly slow down? At this speed, the torque converter is LOCKED. So that would mean to me something driveline. I don't believe a sensor would cause this. This would explain the shutdown at 40 but not at the intersection. Because at 40 the convertor is LOCKED. But isn't at 5mph.

You need to be careful. Sounds to me like you have a broken spider gear or broken pinion or ring and the piece is getting caught between the ring gear and pinion gear during rotation.

Time to pull the rear diff cover and have a look. I'm betting I'm hitting the nail on the head here.

I really appreciate hearing from you sackman9975. I'm going to respond individually to everyone that took the time to jump in.

I am in North Texas and happy to be here!

All of the incidents that occurred at high speed (70 mph) have similar symptoms. They are:
* A "jarring" occurrence as if I had hit a pot hole where there was none.
* The events were instantaneous (without any warning) and the duration was about 1 second.
* The tachometer instantly dropped from 2,000 rpm to 1,000 rpm and literally bounced back up to 2,000.
* When the tachometer bounced back up to 2,000, it was as if it never happened.

To your question, Nope. The truck didn't instantly slow down. As a matter of fact, it really didn't have time to slow down in that one second duration of the event. When the tach bounced, we were back on the trail at 70 mph @ 2,000. I have to figure the during the event, that engine kept spinning without slowing down to 1,000 in one second.

On two occasions (so far) the event repeated itself within 15-20 seconds but never a third time.

The latest event (last week) was different from the others. As you might expect, I've been "on guard" for a repeat performance and was surprised when the symptom of the event changed. While the tachometer once again dropped from 2,000 to 1,000 and bounced back, the bone-rattling symptom of all previous events was replaced with a gentle nudge. As if someone had been in the back seat and gave the driver's seat a little push. If I hadn't been keeping my eyes on the tach, I might have missed the event altogether.

I hear you about the possibility of damage in the rear differential. The symptoms described above have never happened at any speed less than 70 mph. Since the initial event 8-9 months ago, I would say that 90% of the mileage I have put on the truck has been at city speeds below 50 mph. Question: If the rear diff has damage, wouldn't I have seen or heard some feedback from it; even in the form of vibration or noise? The rear diff was serviced three thousand miles ago a before these events began. I understand that while the tech changed out the fluid and replaced the gasket, he didn't necessarily perform a professional inspection. But what do I know. I'm an engineer but NOT a automotive engineer.

I'm not sure these high speed events are even associated with the low speed stalling and shut downs. Maybe the low speed events are associated with a failing old module. I wouldn't be surprised to find that I have two unrelated issues.

Thank you for the warning. I will take your advise and have the diff checked out. I hope you did hit the nail on the head. Thanks sackman9975.

Red Dog

 

[sackman9975]

I hear you about the possibility of damage in the rear differential. The symptoms described above have never happened at any speed less than 70 mph. Since the initial event 8-9 months ago, I would say that 90% of the mileage I have put on the truck has been at city speeds below 50 mph. Question: If the rear diff has damage, wouldn't I have seen or heard some feedback from it; even in the form of vibration or noise? The rear diff was serviced three thousand miles ago a before these events began. I understand that while the tech changed out the fluid and replaced the gasket, he didn't necessarily perform a professional inspection. But what do I know. I'm an engineer but NOT a automotive engineer.

I'm not sure these high speed events are even associated with the low speed stalling and shut downs. Maybe the low speed events are associated with a failing old module. I wouldn't be surprised to find that I have two unrelated issues.

Thank you for the warning. I will take your advise and have the diff checked out. I hope you did hit the nail on the head. Thanks sackman9975.

Red Dog

If it's a broken tooth or piece from a spider gear, broken ear from a clutch most likely you wouldn't even know.
Do you have a limited slip axle (H9)? If yes, did the tech put the additive into the differential?

I guess at 70, that quick of a second and the inertia from the truck isn't going to slow down. But, the torque converter is locked, and if it locked the rear axle for a quick second, it would slow the engine down instantly and you would see it in the tach as well.

The faster you drive, the more that gear lube churns....and the possibility to pick up debris.

I stand by what I'm thinking and there is SOMETHING floating around in that differential.

 

[Bintang Besar]

I had a very similar issue with my 96. I too bought mine 22 years ago with just under 60,000 miles. Maintained religiously and still doing so to this day. At first it would occur on occasion but do fine for a week or so before happening more frequently. Mine would drop rpms briskly like it was going to die but would quickly recover. Turned out to be a bad ignition control module. Replaced it and no further issues. Just a possibility to look at. Good luck.

Thank you for taking the time to read and respond to my "Gremlin" search reds. Your experience with a very similar performance is the closest historical evidence I have seen. During the 70 mph events I have experienced, the truck never indicated an interest in stalling or like it was going to die. But, it sure has at reduced speed <45 mph. It has stumbled and acted like it was going to die several times and in fact did twice.

I will certainly follow up on your suggestion on an ignition control module. I have little confidence with my garage techs. I'm with BigBlue94 with his opinion that "most mechanics" these days are just techies who have zero experience troubleshooting an engine. "

Thanks again reds.

Red Dog

 

[jermil01]

Going back to what @miesk5 said, have you been able to pull any codes? If so, what are they?

 

[Bintang Besar]

If it's a broken tooth or piece from a spider gear, broken ear from a clutch most likely you wouldn't even know.
Do you have a limited slip axle (H9)? If yes, did the tech put the additive into the differential?

I guess at 70, that quick of a second and the inertia from the truck isn't going to slow down. But, the torque converter is locked, and if it locked the rear axle for a quick second, it would slow the engine down instantly and you would see it in the tach as well.

The faster you drive, the more that gear lube churns....and the possibility to pick up debris.

I stand by what I'm thinking and there is SOMETHING floating around in that differential.

sackman9975 I don't have the slightest notion that you are spot on with your long distance diagnosis!

It seems that I do have a limited slip differential. Here is what I know:
1. The tag on the rear diff looks like it came off the assembly line last week and it clearly says 3L55 8.8.
2. The sticker on the driver's side column ID's the axle as H9
3. As for the fluid, the invoice from the garage's Tech advises "Added 5.5 pints of 80w90 Gear Oil Plus BG

 

[Bintang Besar]

sackman9975 I don't have the slightest notion that you are spot on with your long distance diagnosis!

It seems that I do have a limited slip differential. Here is what I know:
1. The tag on the rear diff looks like it came off the assembly line last week and it clearly says 3L55 8.8.
2. The sticker on the driver's side column ID's the axle as H9
3. As for the fluid, the invoice from the garage's Tech advises "Added 5.5 pints of 80w90 Gear Oil Plus BG limited slip additive

sackman9975,
I was re-reading all of the posts I have received regarding my Bronco's issues and found that I made a stupid mistake in my opening statement to your most recent post.

I said "I don't have the slightest notion that you are spot on with your long distance diagnosis!"
I apologize that I wrote/spoke exactly the opposite of what I intended.
I meant to say "I don't have the slightest notion that you AREN'T exactly spot on with your long distance diagnosis!"

 

[sackman9975]

sackman9975,
I was re-reading all of the posts I have received regarding my Bronco's issues and found that I made a stupid mistake in my opening statement to your most recent post.

I said "I don't have the slightest notion that you are spot on with your long distance diagnosis!"
I apologize that I wrote/spoke exactly the opposite of what I intended.
I meant to say "I don't have the slightest notion that you AREN'T exactly spot on with your long distance diagnosis!"

Lol...I knew what you meant.

Still waiting to hear what and if you found anything. Keep us informed.