Fuel issues

[ecgreen]

Just buy the damn spray bottle if you want to do the intake, hook the nozzle to the intake tube and spray until the can is empty. Never understood why you would buy the regular pour can if your running it through the intake. They even sell it in a 2 pack, one to pour in the gas tank, one to spray in the intake... it's like wiping before you poop, it just doesn't make sense!

 

[Dirtman]

My butt itches.

 

[1986RangerXL]

So.. wasn't the ECM.

Okay, no more parts.

Tomorrow I'm going to spend a mind-numbing amount of time trying to diagnose this damn problem

 

[Paulos]

After going through this thread, I don't recall reading if you posted any trouble codes. Were/are there any?

In my experience, simply cleaning the IAC valve doesn't usually do any good. And it's not something that would cause stumbling - just too high or too low of an idle.

Does your 2.9 have a working EGR system (and any codes relating to the EGR)? The internal port going from the EGR valve into the upper intake will clog up after a while and throw an EGR related code.

 

[PetroleumJunkie412]

Every time I've cleaned an iac, it died.

Idk. Just my experience. ??‍

 

[1986RangerXL]

I may have forgotten to post that I bought new IAC and TPS sensors

No check engine light and I haven't checked for codes yet but I know I need to

 

[franklin2]

I may have forgotten to post that I bought new IAC and TPS sensors

No check engine light and I haven't checked for codes yet but I know I need to

You will never get a check engine light. You do not have one. At least I didn't on my 1986 ranger.

 

[1986RangerXL]

You will never get a check engine light. You do not have one. At least I didn't on my 1986 ranger.

I've got one. As to whether or not the damn thing actually works, who knows

 

[Paulos]

The '86 and '87 instrument panels support the CEL, but it's not wired to the ECM. You really need to check for codes before trying to diagnose any further.

If you don't have a code reader, you can use some wire and a 12 volt light bulb. The wire should be big enough to fit tight in the test connectors (I used 12 gauge wire just now and it worked good). I've used the bulbs for the instrument panel or side markers since they have leads to connect to, but a bulb in a socket with leads would be better. The test connectors should be near the fuel pump and ECM/EEC relays. Just follow the diagram and put the light bulb where it shows an analog multi-meter or test light. The wires can be made long enough to be held under your windshield wiper so you can see it from the drivers seat, but you'll have time to walk to the engine compartment after turning the ignition on if you don't have enough wire.
After making the connections (the light bulb will probably be on faintly), put the e-brake on, trans in neutral, and turn the ignition on (without starting the engine). You will have two groups of codes; Key On Engine Off (KOEO) "Self Test Codes", and KOEO "Continuous Codes". The codes on your Ranger are two digit codes, so you will get one or more flashes in a row, a two second pause, then again one or more flashes in a row. If there are multiple trouble codes in that group of codes, there will be a longer pause between double digit codes. Then the ECM will repeat the codes.
After repeating the "Self Test Codes", you will get a pause of several seconds (maybe 10 seconds), a single flash, and then the procedure will be the same as with the "Self Test Codes", only these are now the "Continuous Codes" that have been saved during the time you were actually driving the truck. If you want to repeat the whole process, turn the ignition off, then back on again.
If there are no issues detected during either set of codes, you will get a "pass" code "11" for "Self Test Codes" and "Continuous Codes".
I have the Innova code reader, but I just did the light bulb thing myself, and tested it, so it works as stated.

The Innova 3145 code reader works a lot better than this method, but the cheapest I could find was $30 at AutoZone. Sometimes you can find them cheaper on eBay if you save a search for it to be notified when someone puts them up for auction (I've seen them for $20 or less). I've included a link for the manual for it that includes the Fault Code definitions.

 

[franklin2]

I've got one. As to whether or not the damn thing actually works, who knows

I am not doubting you. But there is no light in the diagrams. It may be some sort of emissions timer light.

 

[wildbill23c]

I am not doubting you. But there is no light in the diagrams. It may be some sort of emissions timer light.

My 87 Ranger just has an emissions light. No check engine light, I think that came about in the 88 Models at least my 88 Bronco 2 has a CEL, still not really useful, and pulling codes isn't too bad just have to pay attention to the light or whatever you are using in order to get the codes right....I have a code reader and my 87 Ranger has yet to give me any codes so its a pain in the a**. My next item up on the block is replacing fuel injectors, I have them in the shop just haven't done them yet, waiting for the weather to cooperate wishing I had a nice fancy shop to work in LOL.

 

[Paulos]

I just pulled this from my '87 STX. In over 20 years I have only seen the No Seat Belt, Brake, and Check Oil lights come on. The others are wired to the connectors of the instrument panel through the flexible PCB, but the wiring from the ECM is not in the harness that connects to it. I researched this the last time I had the dash apart to replace the speedo, and it appears that all I have to do is run a wire from pin 17 of the ECM (which goes to the self-test connector) to the CEL terminal of the instrument panel. I just haven't gotten around to wanting to do it yet .
It's odd that even though I have 4WD, the Low Range and 4X4 lights serve no purpose either.

 

[Paulos]

My 87 Ranger just has an emissions light. No check engine light, I think that came about in the 88 Models at least my 88 Bronco 2 has a CEL, still not really useful, and pulling codes isn't too bad just have to pay attention to the light or whatever you are using in order to get the codes right....I have a code reader and my 87 Ranger has yet to give me any codes so its a pain in the a**. My next item up on the block is replacing fuel injectors, I have them in the shop just haven't done them yet, waiting for the weather to cooperate wishing I had a nice fancy shop to work in LOL.

I highly recommend cleaning the fuel rail before installing the new injectors. I installed new injectors a little over a year ago and went the extra mile to do the acid bath technique that I read about here at TRS. It was time consuming and a bit of a pain, but I'm glad I did.

I would think the ECM would be the problem if it's not giving you ANY codes (not even an "11"). Though it could be operator error , . Nah...

 

[wildbill23c]

I highly recommend cleaning the fuel rail before installing the new injectors. I installed new injectors a little over a year ago and went the extra mile to do the acid bath technique that I read about here at TRS. It was time consuming and a bit of a pain, but I'm glad I did.

I would think the ECM would be the problem if it's not giving you ANY codes (not even an "11"). Though it could be operator error , . Nah...

Cleaning the fuel rail was part of the plan.
It gives code 11, but I figured it would give other codes like a misfire, lean, rich, etc. but all it does is code 11.

 

[Paulos]

Cleaning the fuel rail was part of the plan.
It gives code 11, but I figured it would give other codes like a misfire, lean, rich, etc. but all it does is code 11.

Part of the limitations of OBD1. About the only indication we get of the things that you mentioned is their effect on the O2 sensor and the codes it throws (which is not much help). OBD2 sure would help with troubleshooting these older Rangers.
It seems like throwing parts at them is one of the ways to diagnose their problems . Fortunately, I now have a supply of apparently good new parts/sensors from previous attempts to diagnose them . So, swap with a known good part and go from there.