• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

A4ld to toyo kogyo swap 1986 Ranger. No closed loop operation.


jzcrucible

New Member
Joined
Mar 11, 2020
Messages
4
City
Bakersfield, California
Vehicle Year
1986
Transmission
Manual
Hello new friends, I bought an 86 LX Ranger last summer at an estate sale. It has a service body and I enjoy having my tools close to the jobs I do.
It came to me with a bad a4ld and that being at least the trucks second transmission I decided to swap for a manual transmission.
I found an early toyo kogyo along with all the mechanicals particular to the year and wheel base.
My issue is that I cannot get the truck out of open loop. I've covered what I believe are all the fundamental basics. I have good 5 volt reference, decent vacuum and sound ignition.
What I seem to be missing is VSS signal. The wiring diagrams show pin 3 as a connection point for my missing (literally not installed, lost?) VSS.
What is more I have no factory wire for my pin 3. All my ECM'S (I have the original ecu programmed a4ld, the junk yard 5 speed ecu, and a rebuilt unit because both ECU's had blown capacitors, rust and mold?or some such) have a pin 3 I just don't have the wire.
Question?, don't I in fact need a vehicle motion signal to initiate closed loop?
All I have now are fouled plugs and .863mv on my O2 sensor. As I said I've verified at the sensors voltage and checked pin voltage to verify harness integrity.
If it is a question of check list items, what are the requirements for this truck to enter closed loop?
What could I be missing?
Thank you friends, I look forward to meeting and learning from those that have paved the way.
 
going into closed loop. Should happen independently from having a vss signal. More than likely. The engine is running too cold and not coming up to temp. Replace your thermostat with a motorcraft 195 temp. And sine they are cheap enough. Replace your coolant temp sensor.
 
What engine is in the truck?

Also you didnt pinch/break any O2 wires when installing the trans correct? .8 on the O2 is rich. .5 is IIRC what its supposed to read.

The VSS on early rangers have 0 effect (really) on how it runs.

Im going to *assume* you have a 2.9. Just because its rich doesnt mean its not going into closed loop.

Also, id reccommend a 180* tstat for a 2.9.

Have you pulled codes? If not do that.

One other thing, pull the vacuum line off the fuel pressure regulator (drivers side, rear corner of the fuel rail, assuming its a 2.9) and see if theres gas in the line, the FPRs are 8/10 times what makes a 2.9 go rich.

If you post your question in the engine specfic forum youll also yeild better answers.

Welcome to TRS!
 
going into closed loop. Should happen independently from having a vss signal. More than likely. The engine is running too cold and not coming up to temp. Replace your thermostat with a motorcraft 195 temp. And sine they are cheap enough. Replace your coolant temp sensor.
Thank you for your helpful input. I had recently replaced the thermostat and water pump. My wrong assumption may have been the temp set of the t stat. On my way to work this morning I did pay particular attention to the gauge. Yes is is running very cold. And upon reaching the set point the temp plunges.
Thanks Ranger Fab works. I came home with a 195° t stat and will certainly keep you posted.
 
What engine is in the truck?

Also you didnt pinch/break any O2 wires when installing the trans correct? .8 on the O2 is rich. .5 is IIRC what its supposed to read.

The VSS on early rangers have 0 effect (really) on how it runs.

Im going to *assume* you have a 2.9. Just because its rich doesnt mean its not going into closed loop.

Also, id reccommend a 180* tstat for a 2.9.

Have you pulled codes? If not do that.

One other thing, pull the vacuum line off the fuel pressure regulator (drivers side, rear corner of the fuel rail, assuming its a 2.9) and see if theres gas in the line, the FPRs are 8/10 times what makes a 2.9 go rich.

If you post your question in the engine specfic forum youll also yeild better answers.

Welcome to TRS!
Hello, and thank you as well for your input. Codes? Not yet from my new ECU. The old one was so faulty it couldn't record anything. I got gibberish and even that irregularly. Hence the new rebuilt ECU.
Lots of dry rot on the O2 sensor whip, ignition control module, and the transmission. Spent quality time rebuilding that part of the harness. Although my O2 sensor signal needs a bit of attention now. I wasn't very kind with my piercing probe.
Yep I've the 2.9. A lot must have changed from early 86 to late 87. I had a big Country Squire and it was sequential multi- port EFI. This 2.9 fires 3 and 3. I did not know that.
Thank you for the FPR tip. I did pull off the vacuum line and no leak yet. But you bet I'll be watching.
 
Hello, and thank you as well for your input. Codes? Not yet from my new ECU. The old one was so faulty it couldn't record anything. I got gibberish and even that irregularly. Hence the new rebuilt ECU.
Lots of dry rot on the O2 sensor whip, ignition control module, and the transmission. Spent quality time rebuilding that part of the harness. Although my O2 sensor signal needs a bit of attention now. I wasn't very kind with my piercing probe.
Yep I've the 2.9. A lot must have changed from early 86 to late 87. I had a big Country Squire and it was sequential multi- port EFI. This 2.9 fires 3 and 3. I did not know that.
Thank you for the FPR tip. I did pull off the vacuum line and no leak yet. But you bet I'll be watching.
The 302 was the only engine to my knowledge (other then the later escort 1.9's) to get SEFI. "Batch fire" (like the 2.9) was actually the most common setup.

Defiantly get the O2 harness back into shape. If you want unplug the O2 and drive it for a while. It wont hurt anything (and then it really will stay in open loop) and see if anything improves.
 
Not all 302s had SEFI. My '86 F150 and the '89 Crown Vic engine I used for my 302 swap are both batch fired.

How do you know it's staying in open loop mode? I'm asking because I don't know.

I will also echo the statement about the VSS not really doing much. It is used on 4x4 trucks with electric shift transfer cases to prevent shifting into 4 low while moving, and possibly for trucks that have RABS but I'm not sure why it would matter in regards to open/closed loop, that is more dependent on engine temp.
 
Not all 302s had SEFI. My '86 F150 and the '89 Crown Vic engine I used for my 302 swap are both batch fired.

How do you know it's staying in open loop mode? I'm asking because I don't know.

I will also echo the statement about the VSS not really doing much. It is used on 4x4 trucks with electric shift transfer cases to prevent shifting into 4 low while moving, and possibly for trucks that have RABS but I'm not sure why it would matter in regards to open/closed loop, that is more dependent on engine temp.
Hmm...maybe it was just stang 302s that got SEFI?
 
I'm under the impression that any speed density EFI setup is batch fired. I am not super familiar with Mustangs, I think they could go either way, the early EFI Fox body cars may have been speed density and later changed to mass air. I have only dealt with a couple of them. We junked one that was either an '86 or '87 that was definitely speed density, it did not have a MAF sensor but did have the 5.0 HO plate on the upper intake.

A quick look at engine wiring diagrams for any vehicle in question will tell you for sure... batch fired shares a common ground for both banks and each bank has a common power wire.
 
Several EEC-IV's could run SEFI with correct wiring from injectors and firmware in the PCM, each injector needs its own wire to PCM, of course, and PCM needs to have the internal circuit board for those wires
The A9L and A9P used in Mustang V8s did IIRC

For OP, to get Closed Loop
The engine/coolant temp must show above 140degF(ECT sensor), not temp gauge sender
The MAP sensor must be working
The RPM sensor(PIP) must be working
The O2 sensor must be changing voltages quickly, this ONLY happens when they are heated above 650degF, this is why O2 sensors are Heated sensors, they have 2 wires for the heater inside them, a 12v(key on) and a Ground
Other 2 wires are for the .1-.9 sensor voltage

If O2 sensor does responded quickly to changes the computer makes in the Mix Ratios then computer stays in Open Loop
And runs engine Richer, which is safer than Lean, which melts pistons, lol

Just looking at 1986 2.9l Wiring diagram
Shows it has a Knock sensor, this could cause Open Loop as well if its failed

And the heated part of O2 uses a Fusible link, there should be a Grey/yellow stripe wire on the O2 connector, it should show 12volts Key ON if that fusible link is not blown
 
Last edited:
Good afternoon fellow Ranger fans. I guess you folks have some idea how much I love my service truck Ranger. It's just an old 86 2.9L. But, the truck has my heart, my wallet and my attention.
It just runs like crap. I have chased this misfire and used the worksheet found on this site and still.....
I wrote this email and here is a copy for you all to consider.
Thanks
John

Hello and good afternoon. My name is John and I live in Bakersfield California. I got this email from an old thread on the Ranger Station site.
I hope you can give me some much needed feedback and insight to my misfire.
I drive an 86 Ranger with the 2.9L and the motor misfires and fouls my plugs really quickly. I have changed my sensors and computer, my distributor and its harness. At the time I was chasing voltage drops and a strange voltage value from my Spout. Almost 11 volts, key on engine off. And running voltage was 3 volts or a bit more or less.
I imagined this voltage coming from a shorted ignition control module and fiddling with the distributor I located a bad connection for the module into the distributor. Hence, the new unit. Unfortunately I later discovered the 3 wires that connect the module were manufactured in the wrong order. The power and pip were internally reversed.
Warantied and replaced along with a new module. And still I have a constant misfire. My timing lite flashes intermittently with both spout in and out. My voltage at the coil is plus 14 and amperage is very minimal, (can't remember the exact value).
I am thinking of a trip to the shop and hooking up an oscilloscope.
I, at one time received my ASE credentials in engine performance and auto electrical. I mentioned this not because I puff myself up, but rather to inform you that I believe in my work so far being quality.
But obviously I am missing something.
What do you think? What comes to mind for you? Me?, I'm shopping for a newer Ranger and that is killing me!
This vehicle has a service body kit and I can't work my "side hustle" without it.
Thank you for taking the time to read this and consider my problem.
Sincere regards,
John Z.
jzcrucible@gmail.com
 
04n27EE.gif
 

Sponsored Ad


Sponsored Ad

TRS Events

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Ranger Adventure Video

TRS Merchandise

Follow TRS On Instagram

TRS Sponsors


Sponsored Ad


Sponsored Ad


Amazon Deals

Sponsored Ad

Back
Top