Starts rough in the morning, won't start at all in heat of afternoon.

How is it going everyone, new member here.

I have been searching around for the solution to this problem and of course nothing is 100% exact same senario. So I hope to run this by some of you and maybe come to a solution.

I recently picked up a 1988 Ford Ranger 2.9, manual 2wd last week. It ran fine when I test drove it, the owner drove it around now problem after that (insisted on fixing the leak at the valve cover before selling) and I was able to drive it home no problem (about 20 miles).

I let the truck sit for about 3-4 days as my family was in town and had a rental car. I went back to work tuesday and it got me to and from work no problem (1 mile round trip). Wednesday and Thursday I got to work, but then the truck started to have issues starting in the afternoon. It would crank healthy, and if you gave it a little gas and a few breaks here and there it would fire up after about 10 minutes.

Friday however, hottest day sofar. I got the truck to work, stalled once in the morning (I just attributed it to being out of practice with a manual) and then got to work no problem. The afternoon came and it was time to head home, and it refused to start for about an hour. I walked home and waited until night to see if cooling off would do the trick to get it home. It was still 85 at 9pm and it still refused.

Now it's cranking fine and if you give it gas it will crank, rev up to about 1500-2000 and then immediately cut off. Sometimes it will rev up, drop down and spike up again for a split second like it was on the brink of starting.

So now Im looking at my options. I have AAA and was considering towing it to a mechanic, but Id rather do the work myself if possible. Handicap is I live in an apartment complex and all tools I would have to go buy (my tools are back home home 3000 miles away) and am in the military so money really doesnt grow on trees.

According to what I've researched, it could be the TFI or the distributor. I feel like with the lack of tools and time, I'm kind of going into this blind, so any help is appreciated very much. Any questions I should be able to answer or get an answer for you. Thanks



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Welcome to TRS

First thing I would do is to determine whether it is Spark or Fuel that is causing the no Start, and no tools needed

You will need some gasoline in a spray bottle or a can of Quick Starter(ether)
Take off the air filter cover and remove air filter.
Now try to start engine FIRST, to see if it is a No Start

If so, Spray "fuel" into the plenum(larger air tube) going to the intake(no MAF sensor on 1988 2.9l)
Try to start engine
If it fires up and then dies Spark is working, but you are not getting fuel from the fuel injectors

If it doesn't fire up then Spark is the problem
Its a 50/50 test, old school and reliable

Repeat this test a few times, suction from cranking should pull enough fumes in but you can open throttle a bit to make sure fuel is getting into the engine.
Don't push gas pedal to the floor when cranking, that turns OFF the fuel injectors

Yes, the TFI modules on the side of the distributors would get heat sensitive as they got older, so if its spark related then not a bad place to start
TFI diagnostic here: http://therangerstation.com/tech_library/TFI_Diagnostic.shtml

When you turn on the key, you can hear the fuel pumps running from inside the cab, there are two(on '88), a HUMMMM, but it only lasts 2 seconds, its a safety thing.
But pumps will run for 2 seconds EACH TIME you turn the key from OFF to RUN(on)
So repeat this as much as needed to make sure you hear the fuel pumps
Doing this also increases fuel pressure at the engine in case it is being lost when vehicle sits, you can't over pressure the system, there is a fuel pressure regulator that releases fuel back to the tank when it is above 40psi at the engine.
So key off/key on a few times is also a good test to see if fuel pressure is an issue

TFI or Coolant temp sensor is my guess

What happens with the coolant temp sensor? Does it read the coolant isnt at the temp it should be so to preserve the engine it cuts it? Or am I looking too far into it?

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Basically works like a choke. It richens (dumps more fuel) into the mix on a cold engine, leans it out (takes fuel away) when warmed up.

Well the Computer runs in Choke Mode, if ECT(engine coolant temp) sensor tells it the engine/coolant is Cold, under 140degF

Failing ECT sensor could cause stalls when engine is cold(no Choke), but engine would restart, or Rich running when engine is warmed up, poor MPG, but still runs OK

And no there is nothing in the computer or any electrics that would cut the engine off if it gets too hot, ask anyone who has blown a head gasket or cracked a head,

Just guessing here, could a pick up coil in the distributor cause this problem. A few years back my 87 would start and after a few miles die. I seem to recall i had to pull the distributor out and it was under the rotor plate.