1988 Ranger still dying at certain temp

[Rajendora]

Again with this thing. We are right back at square one with the mechanic. The truck starts cold, warms up to about where the thermostat would open, and then drops dead. Our only way of driving it now is to sit with my foot on the gas pedal at 1500 rpms (less than that and it dies) until the indicater is at the top of the L in normal, its normal running temp, 10 to 15, sometimes 20 minutes wasting 4$ a gallong gas in wonderful Cali. If it dies before then, we have to wait for it to cool down again before it will start. Everything in the ignition sequence has been changed, the ignition module twice! All I can think of every time I check the radiator is damn, that fluid is awfully neon. IS it remotely possible that the fluid is too 'fluid' and making the water temp off? OR might it be the thermostat is too high or too low? (I'm a girl so go easy on me, they didn't let my generation take automotive classes, we had 'charm' instead. Bleh. Thank you everyone for your help.

 

[Paulos]

I though you said that a new ignition module solved the problem? If it worked for a while and is now doing the same thing, I would suspect that you have a poor quality ignition module. Places like AutoZone, etc usually sell these with a lifetime guarantee.

 

[Rajendora]

CarQuest, Motorcraft. The last one actually improved matters, but I'm wondering what might have blown out the first 'new one'. I did not think it needed changing, the mechanic did.

 

[Nez'sRanger]

I got a hunch that your tfi (ignition module) is overheating in it's current location on the distributor. Which may be the case, especially if the radiator and heater core haven't been changed (or flushed) in the past 30 years. Same goes for inside the engine. When I changed the heads on mine, I found the coolant ports inside the engine were caked with who knows what kinda gunk. All of that will limit the ability to cool off the very back of the engine, where our beloved tfi's are mounted. It's even worse if your truck has A/C... Beyond adding an extra amount of heat in front of the radiator, the A/C system further clutters the engine bay and doesn't allow proper air flow to the back of the engine, pretty much isolating and cooking what's back there.
All that to say, if the engine itself isn't overheating, I recommend doing the tfi remote mount. There is a wonderful article on how to do that in the tech section of this site.
I like to beat the coolant system drum as well, so if you can afford it (and haven't done so already) have the radiator and heater core, their hoses, and even the thermostat replaced, and also run a coolant system flush to eat the gunk out of the inside of the block.
Some of the other guys will chime in if I'm missing something.

 

[Paulos]

The Motorcraft (if new) should have lasted a while. Carquest..... who knows. I bought a new module last year from Advance Auto with a lifetime guarantee and haven't had a problem with it. Well, there was a problem the following morning. The 32 year old ignition module connector didn't make a tight fit on the new module, so I had to replace the connector. No problems since then though. Rock Auto is pretty reasonable price-wise on the connectors, which cost me around $25 at Advance. I found (on the side of the road) that I could pull the red plastic strip out of the old connector and use a small screwdriver to tweak the electrical contacts inside the connector to temporarily tighten them. It worked until I could buy and install a new one.

 

[PetroleumJunkie412]

You have a sensor string issue. Most likely with ignition control or with engine.temperature. My money is on tfi.

Remote mount your tfi module. There are aftermarket remote mounting kits that work very well if you don't want to make the harness.

Invest in a Motorcraft tfi module from the dealer. Make.sure it's installed with thermal paste, NOT DIELECTRIC GREASE.

IF YOUR MECHANIC TELLS YOU THEY'RE THE SAME THING, AND USES DIELECTRIC GREASE, SLAP THE SH*T OUT OF HIM/HER.

Change your engine coolant temp sensor.

Replace the hall effect sensor in your distributor.

Use only Motorcraft parts. Stock 2.9 engines do not like aftermarket. They are very picky on electronics

The only aftermarket part to use is a polymer IAT sensor made by BWD. Replace that too.

 

[Paulos]

One way to test the connector is to start the truck, then wiggle the connector (up, down, sideways, and gently in and out) to see if the engine dies. My old connector allowed me to drive 20 miles (halfway to work) before it decided I needed to be a roadside mechanic. Sometimes they don't like to stay in all the way.

 

[Paulos]

Oh, and I hate to say it, but you may have a mechanic problem also. It wouldn't hurt to look for someone that is familiar with these older trucks, and knows what to look for.

 

[Rajendora]

@Nez: I wonder because it's been there ever since, why would it act up now? I'll print that out and shove it up under (leaves typo) the mechanic's nose. No AC, unfortunately.
It's had a complete radiator change (leaking damned plastic!) and flush this past spring. It tends to get a new one every 5 years. I'll ask about a total flush, though. Something is connected to that system, I just know it. The engine is not overheating, it hasn't had a chance. It's got to be something to do with the temperature gauges or thermostats, but we just changed the one in the pump.

@PetroleumJunkie412
"You have a sensor string issue. Most likely with ignition control or with engine.temperature. My money is on tfi."

It's got to be a temp sensor, we've replaced the whole ignition sequence. At least it starts now, but I'm afraid it's going to just cascade yet again.

@ Paulos. That lead to the second TFI, I'm wondering if the part wasn't just bad out of the box. Plus the goop issue, there was no goop in the box.

Which leads me to the whole slap the poop out of the mechanic idea.

We've come to the conclusion that we are going to pay this guy off, as the truck is running much better when it runs, and go to another mechanic who comes highly recommended and cut his teeth on 80's cars. Thank you everyone.

 

[Rajendora]

I'm updating this because if it happens to anyone else they'll be driven as mad as I'm getting. I've found far too many threads everywhere on the net where this happens and then no one concludes it. It's been running fairly well if I just warm it up to a certain temp, when the water starts circulating for about 12 days, which is what made me think it was something to do with the temp or the radiator cycle or what ever. Then it started dying on us at any temp, any speed. I'm still holding out till payday (and paying off the mechanic day) but it will be another month after that until we can do anything further, like get a new EEC. It is cascading again. We have a real good start, hold my foot on the gas, wait for it to warm up and then it dies a little later, then dies again, and starts right up after I take a few deep breaths and not scream (maybe I should) but now it's trying to die when I have my foot on the gas at 35 to 45, engine light will flash on, then it will surge and behave. I'm going to update this again when we find an answer. Thank you all.

 

[Paulos]

Thanks for the update. Yeah, it's kind of frustrating when people don't follow up with the solution to their problem. You find a post on a forum where someone describes the same problem you have, but they don't post the solution in the end.

It's unfortunate that you can't do any of the troubleshooting/work yourself and have to deal with a mechanic. Couldn't your husband coach you through the ignition module/connector/ECM replacement/repair?

Just shutting down like it's doing is definitely a symptom of the ignition module. As I mentioned before, the new module I bought several months ago worked until the following morning on the way to work. It turns out the ignition module electrical connector did not fit as tight on the new module due to the new module having slightly thinner spade terminals (the 30 year old ignition module connector didn't help either). Temporarily tightening the connector's contacts got me by until I could change the connector. This is the first thing I would try.

And as you mentioned, it's possible that it could be the ECM/computer. I have read several times on this forum where people have opened up their ECM's to find bad capacitors and corrosion.

 

[rusty ol ranger]

Have you changed/checked the coolant sensor and wireing? Not the single stud one that goes to the gauge, but the 2 terminal plug in one?

 

[Rajendora]

Alright, it's been a few months and the damned beast is behaving fine. I still let it warm up ten minutes before I drive anywhere, so no sudden shutting down when it reaches a certain temp. That issue is for another mechanic. It's also been getting better gas milage with the warm up.

Hubby had a stroke years back and walks with a quad cane. The cane has has four prongs at the bottom and takes up a lot of room in the foot area, and hits right where the connection between the two wires is up behind the carpet. When it finally would not start one day, checking that connection solved the problem right away. Next time, same thing. Truck runs great, no start up problem, no dying with the foot off the gas.

Conclusion: We will replace those wires, or just the connector, which ever, that has been damaged or cracked, and he keeps his darned cane off it! I hope to heck this helps anyone else with this issue.

 

[Rajendora]

Have you changed/checked the coolant sensor and wireing? Not the single stud one that goes to the gauge, but the 2 terminal plug in one?

That we will try next for the shutting down at temp issue, thank you!

 

[Rajendora]

Thanks for the update. Yeah, it's kind of frustrating when people don't follow up with the solution to their problem. You find a post on a forum where someone describes the same problem you have, but they don't post the solution in the end.

It's unfortunate that you can't do any of the troubleshooting/work yourself and have to deal with a mechanic. Couldn't your husband coach you through the ignition module/connector/ECM replacement/repair?

He could, but I find the manuals often make me less likely to murder him. ^_^

Just shutting down like it's doing is definitely a symptom of the ignition module. As I mentioned before, the new module I bought several months ago worked until the following morning on the way to work. It turns out the ignition module electrical connector did not fit as tight on the new module due to the new module having slightly thinner spade terminals (the 30 year old ignition module connector didn't help either). Temporarily tightening the connector's contacts got me by until I could change the connector. This is the first thing I would try.

Two modules and the proper grease later, that problem is solved. Mechanic did not charge us for the second module.

And as you mentioned, it's possible that it could be the ECM/computer. I have read several times on this forum where people have opened up their ECM's to find bad capacitors and corrosion.

Definitely the connections to the brain. When we are feeling a little more brave financially (in case something breaks the rest of the way because we did not leave 'well enough alone') that is the next thing. New brain, new wires.