General discussion and trouble shooting. I recently bought a 1988 ranger with the 2.3 and 5 speed, 2wd long bed XLT. I call it the creampuff. I bought this truck as a platform to teach my kids to drive a manual. I just cant help myself, I want everything to work as designed on it. It has 418,679 miles on it, and has recently had the head reworked. It is completely stock and original. I'm amazed it still runs and doesn't smoke. Here are the things that aren't right and what I've checked. Please feel free to add your input.

Heat - I got the blower working but do not feel any hot water circulating in the hoses. Installed thermostat (didn't have one). Dash lever feels like its working but I haven't found the valve yet.

A/C - Ill get to that eventually. All there, no belt, questionable.

Temp gauge - Moves up when key is first turned on, then stays on cold. Haven't located the sending unit yet.

Fuel gauge - sending unit I suspect.

Cuts out (sputters) at constant speed / uneven idle / low power / revs up unexpectedly - I group these together because I suspect they are related. New plugs installed. Some vacuum leaks found but suspect more. Timing is probably off (couldnt find the plug to disconnect the advance. was set at 30 BTDC, set to 10 now). I suspect vacuum leaks, TPS, MAP, and timing. Haven't had time to troubleshoot yet.

Oil pressure light flickers - only when turning left. no engine noise. no signs of low pressure but I do not have an actual gauge hooked up yet. Light used to stay on dimly. While changing the oil I fiddled with the sensor connection and now it flickers brightly.

Several interior bits and pieces - door panels, cracked dash, faded everything, bad door & window seals etc. Is it normal for the seat mounts to rust through? I looked at a few in junkyards and it seems to be common. Can you buy just the mounts?

Thanks guys! looking forward to the conversations.

 

IIRC the spout connector is near the battery tray, open it then you can set the timing to 10 degrees
You might need to remove the glove box to find the heat valve, luckily it's cable controlled not the vacuum controlled crap.
The 2 wire engine coolant temp sensor is on the drivers side midway back. My guess is the single wire temp gauge sender is in the same area. Remove the wire and ground it to the engine block & should read full hot on the gauge.
Teaching the kids how to drive a stick. Right on.
I would check fuel pressure test with a vacuum gauge and check for trouble codes. If you dont want to count flashes an innova 3145 is 25 bucks and pulling codes with it is super simple.
Good luck with the project.

 

I'm still learning how to use this forum so please forgive any double posts.

Do you have a preferred OBD1 & OBD2 scan tool? I could use both but don't want two scanners.

Thanks for the info. I'll buy/borrow a timing light when I get home in two weeks and start with that.

Hot water valve will take some digging. I looked behind the glove box but didn't have time to really dig for it. The dash lever is hooked up, and I can hear something moving in there. The apparent lack of flow through the heater hoses makes me suspect the valve is closed. The thermostat was missing but I installed a new one.

Your thoughts on the TPS? If i back off the stop screw on the intake butterfly it will idle down, however after a short drive it will start idling around 2000 RPM. wiggle the stop screw again and it drops, but is unpredictable. The IAC valve seems to work properly. There is no MAF on this truck. The MAP mounted on the firewall had rotten hoses on it, which have been replaced. And what i suspect is the vapor emissions canister hose was unhooked from under the throtle body. hooked that back up. I'm sure there are more vacuum leaks to be found.

The previous owner installed an electric radiator fan. I'm fine with that but he jumped into the coil wire for power. That will be rerouted to another source, but could the power drop cause erratic running? I know that kinda an open ended question.

Still learning the truck and having fun tinkering with it. My kids are learning right along with me. My wife just doesn't understand my fascination with it.

 

So many questions in one shot makes answering more difficult.

The heater core is likely plugged with sludge. Poor maintenance of the coolant, evidenced by the thermostat removal, will lead to the core being filled and left that way. Get up to operating temp and grab both heater hoses. They should be equally hot, and if not, the core is plugged. They are cheap and easy to replace by removal of a panel behind below the glove box area. Don't remember if the glove box needs to be removed, but you get a LOT better view and you can sit upright while doing the swap.
Do not power the fan from the coil. Don't likely need the fan much anyway until the A/C is resurrected as 2.3's run cool. Sometimes too cool on a cold winter night... Cardboard radiator shield sometimes helps when real cold.
Seat tracks rusted? Dunno, but they are a bolt-in replacement if you can find some old ones that are not rusted. Remove the track to body bolts, and remove the seat and tracks as one, replace, and reinstall the seat.
The temp gauge sender is on the side of the block just above the oil filter, single wire. If you ground the wire, the light will light or the gauge will go full HOT if the key is ON.
If the MAP is bad, your idle will wander all over the place.
If the IAC is gummed or bad, you will get no 'cold fast idle' on startup from cold, and the idle will be over or under the suggested 750 rpm. The throttle stop is a 'kill' idle that closes the throttle all the way(close enough it should NOT idle) when the IAC is told to close, or is disconnected. It is to prevent engine run-on by closing the throttle so much it can't run. The IAC should give cold fast idle on start, bump for the A/C engage, and also if you have power steering, bump the idle when the PS pump is about to load up as you turn the wheel parking.. (at idle). When a cold engine starts, the idle should be above 1k rpm, then step down in increments as the engine warms, and finally come to a 'hot idle' of around 750. If it is too low, you can add some with the idle hard-stop screw to get to 750. Higher indicates(to me) a sticky throttle plate. Check for gum/varnish, rats, cats, and small critters that may have taken nest, or jammed the external linkage or cable.
There should be a line from the vapor canister ( over near the front drivers side of the radiator) to the underside of the intake manifold/throttle body. There should be an electric solenoid that opens/closes to trap/release the vapor, hopefully to the engine to burn on command.
The oil sender is on the side of the cylinder head, above the temp sender. If you ground the wire, the light should light. I think that year had actual sending unit if you have an oil pressure 'gauge' instead of a light. If no sending unit, grounding the wire should give 'middle of the gauge' oil pressure.
Take a look inside the radiator for 'bloom' on the ends of the tubes that block flow. If you have it, you'll likely need a heavy clean or replacement of the radiator. If it is just full or rusty looking water, drain, flush, drain flush.... drain flush... or get a Prestone 'back flush' that goes into the heater hose and follow directions. Get it clean, add 1/2 the capacity (10 quarts?) of the cooling system, and fill the remainder with clean, drinking quality water(hopefully non-mineral).

tom

 

If you go to Amazon.com you can check out owners reviews for many different OBD1 & OBd2 combo scanners. I have an OBD1 for my 87 Ranger & a seperate OBD2 scanner for my 97 Explorer.

As for the TPS, if it's whacked you will get a trouble code when you scan the computer.

When my 87 was pinging & stalling at low RPM's i got a code 53 "TPS voltage too high"
Hooked up my CP9087 to the TPS & output voltage was jumping all over the place,

 

Tom: sorry about the number of questions. That never occurred to me before, but I see what you mean. Cooling system was full of rusty water. Flushed and filled with just water for now until I get the heater core flowing right, then I'll fill it properly. Heater hoses dont get warm at all right now. May be plugged but i'm going to investigate the valve first, then the core itself.
I appreciate the info on the sending units for oil pressure and water temp. I'll look into those when I get back home.
The MAP might as well have been unhooked. Hoses were rotted through. Replaced hoses but I suspect more are rotten, just have to track them all down. The vapor canister was unhooked completely. Reattached hose. Not sure about an electric solenoid but i'll look into it.
TPS still needs investigating. Head was reworked prior to my purchase. Engine doesn't smoke and seems to run fairly well considering the mileage. Just won't idle right and not much power. Some stumbling when running at steady speed on the road. IAC is clean and seems to function properly.
Fan will be rewired. I'll probably put a kill switch on it inside the cab. I have the original shroud but not the original fan, but im thinking i'll just keep the electric one and wire it properly.

XLT: I'll do my research on the scanners. I'm sure one will keep me from guessing as much. "LOAD THE PARTS CANNON AND FIRE AT WILL" is not what I want to do.

Another question for you ranger guys - Have you had to replace the HVAC blower motor? Do they move much air or is mine just wore out? It blows and changes speeds, but on high it doesn't move any more air than a newer one on low speed. Wasn't working when I got the truck but cleaning and wiggling the plug got it going. Controls send air flow to the proper places etc. Weak blower?

I don't want to spend a lot of money on a truck that I may not keep. The engineer in me is enjoying fiddling with it. And anything that has run nearly 1/2 a million miles holds a place in my heart.

 

I had a blower motor with worn out brushes that would function and then stop, repeating the cycle until I replace the motor. As I remember, it did not seem to be weak before its final quit, it would just stop running. I suppose it may have been doing otherwise, but I noticed it driving at freeway speed on a trip on the way home when it started to get a bit warm and there was little airflow. Changing speeds had no effect as the motor was not turning. I spent the $30 for a new motor, re-used the blower wheel & connector using the supplied electrical butt(I think) connectors. If you want to know, check voltage at the resistor pack built into the side of the plenum, underhood, near the blower motor, to see if the switch is cutting out or the motor.
If the idle is all over the place, sometimes good, sometimes terrible, the MAP may be fooling the computer with off the wall 'load' information, and the computer responds by changing the fuel injection pulse, making it too lean or too rich for a good idle. I think disconnecting a bad MAP will let the computer throw a code, and substitute 'middle' values and get a more-stable idle. I have been wrong.
I have a scanner that uses a 9-volt battery for EEC-IV only. Was ~$30 20 years ago. They are on sale(or were) at Rock and other places trying to get rid of the old stock for around $10 or less. They will beep and flash a LED to help in counting the pulses. A LOT better than trying to watch a VOM needle sweep. My VOM was too slow to respond, making the observation difficult, so 'reader'. It has paid for itself with the information provided and the booklet that explained a lot of the codes and their varying meanings. The same company made a 'test' setup to check various emissions components such as the TFI, TPS, and so on. If it had resistance or 'switching' and could be 'fooled', it was testable. Multiple clip on jumpers in the kit. Have not looked recently to check availability.
I also have a HF OBD-II, not used yet, but would go for an ELM scan tool and the Forscan software if looking now. Forscan was free, and the ELM tools were in the $20 range. Beware cheap 'knockoffs' from a Far East country, spend a few and get one from the Company in AZ. They guarantee their product, while the others can't do much from Singapore or Hong Kong.
tom

 

Thanks for the info. I'm offshore right now but gathering info so my very short time at home will be more productive. Timing/vacuum leaks/idling right are what's on my mind right now. The rest is mostly fluff just to make the truck nicer.

Inserted is a vacuum line diagram for my truck. It's not showing any solenoid valves for the vapor recovery canister. Are they supposed to be there and just not shown?
Also, what are the two things in the lower left corner? A/CL DV and A/CL BI MET.
Air Conditioning? BiMetallic? I'm guessing this has to do with disabling the compressor when you need power. Am I even close?

Many Thanks, Tom

 

Air cleaner diverter valve and bi-metal valve. Many have a bi-metal valve that opens when it is above 50-60F. Below that it is closed, and a vacuum develops. That vacuum is used on a diaphragm flap operator plumbed into the intake bellows or tube. The flap causes heated air from the 'stove' around the exhaust manifold to be sucked into the engine instead of cold air from the normal path. I have one that may or may not work any more, along with a 'bendable' aluminum tube leading from the stove to the flap near the air cleaner box. There should be some foam rubber around the vacuum port open to air when the temperature sensitive bi-metal disc flips to vent the vacuum.
The vapor recovery is not really a 'vacuum' line, though it is exposed to manifold vacuum when the solenoid valve opens. The 'dashed line' indicates it is optional (likely in 49-state emissions). Your layout sure looks similar to the 85 CA emissions EFI 2.3 layout. All I can see is the same, from memory of what's there. Even the little canister taped to the side of stuff hanging off the throttle body.
tom

 

Thanks, Tom. Air Cleaner never crossed my mind. Mind you I'm not near my truck right now and this is a diagram I found on line. Everything looks correct to my memory. The "warm air" intake system is missing at least the hose, I'll have to look for the valve. I've seen the lines leading to the EGR solenoids, just didn't know what they were. For some reason they're red and green hard plastic lines. I'll have to locate the remainder of the EGR system and check it out, including the reservoir. The MAP is mounted to the firewall. The reservoir is a little bitty thing, about the size of an aspirin bottle. The lines to this were rotten and have been replaced. I didn't realize what that was either until I started looking at forums. The vapor cannister is intact, and the hose is (now) connected to the intake. I'll look for the solenoid valve on this.

I appreciate your help. My plan is to pull the lines one at a time and hook up my vacuum pump. We'll see what's leaking that way.

Tom

 

I'm subscribing to this thread. Tom, your 88 reminds me a lot of the 86 that I had in high school. Lately, as I become more and more confuzzled with all the high-tech wizardry in the newer vehicles, I'm really starting to miss the simplicity of the older stuff. I could fix anything that broke on my 86 with just basic hand tools and a little bit of patience. Any maintenance it needed was dirt cheap; tune-ups did not cost $1000, they cost $30-40. I'm kind of in the mood to restore a first generation Ranger to relive those memories. Mine had the same 2.3 liter, but an earlier Mazda 5-speed. It was called the Toyo Kogyo 5-speed. What you have should be the M5OD, although it could possibly be a Mitsubishi trannny. Post a picture of your shifter and I can tell you for sure. I'd like to see pictures of the truck anyway if you can post any!

 

Thanks for the support Rebel.

 

So heres where I am with it running right. Got the vacuum leaks fixed. Set the timing properly. Thanks for the help finding the connector hidden under the battery.

The truck runs great except at idle. Testing the TPS for resistance and I notice that it shows "open" at zero throttle. Should it ever show open? I wouldn't think so. slightly off zero it shows 23 ohms and slowly decreases to about 2 ohms at WOT. I'm thinking the TPS is bad. any thoughts? also where do you find one? Not available at the parts stores.

Thanks again for any assistance.

 

Yep! That looks like the shifter of the M5-OD. Decent tranny but check the shifter for evidence of leaking fluid. It uses Mercon V automatic trans fluid. There's three rubber plugs near the top of the case which tend to leak, especially after nearly 30 years. Might want to get that serviced. Otherwise she looks pretty good for her age and mileage!

 

The original(when?) TPS were adjustable as to their 'zero' or 'full closed' point. I don't remember the number of ohms. The thing to look for is 'dropout' of the resistance as you go from full closed to full open. If you have an adjustable TPS(the attach holes are elongated) you can adjust it to a non-zero full stop position, and tighten. Re-connect the battery and see what happens. I actually mean 'infinite' when I say non-zero...
You do not want zero ohms, nor infinite, at full closed. I think.
I would consider elongating the mounting holes, if that would help, to make it partly 'adjustable'. I think the following years had similar readings and attachments, but the electrical connectors were different. Check at a parts house for a newer TPS for a 2.3/2.5, and compare. I bet the connectors are different, but the content the same.
Get one, and snip-snip, solder-solder, and heat shrink. Viola.
tom

p.s. the lines to the EGR solenoids were hard colored plastic from the factory. If they get damaged or cracked, you can splice them using regular 'rubber' vacuum line. The vacuum reservoir is (likely) rearward from the starter relay and EGR solenoids and below the heater plenum. It should(mine does) have red(I think) plastic lines feeding it. There should be a check valve in there to keep vacuum when the intake manifold vacuum goes away. Not used for anything on mine, but would work for power brake booster, and HVAC if it used vacuum 'motors'.
tom