1990 ranger cranks but wont catch
 

Hi all,

I bought a 1990 ford ranger a few weeks ago, after it had been sitting in a field for about 5 years. It ran really well for about 3 weeks, and then randomly stalled out on the road. I had it towed home, and the next morning, it started right up. I turned it off, and then it wouldn't start again. I diagnosed a bad fuel pump, so I replaced it, as well as the fuel filter.

Still no start. I had spark, fuel, so i did a compression test. (135psi in every cylinder) After the compression test, it started right up. i let it run for a bit, and turned it off. An hour later, it wouldn't start. Based on how the compression test worked, i took out all the spark plugs, turned off the fuel pump, and ran the starter 4 or 5 times. Put it all back together, and started right up. If I turn it off and wait for longer than 15 minutes, I can't get it started again. My spark plug trick works, but i obviously cant do that everytime i want the truck to start.

I've replaced quite a few things trying to isolate the issue:
-Fuel pump/filter
-Fuel Pressure regulator
-Throttle position switch
-coolant temp sensor
-Thermostat
-water pump

Some other facts:
-temp gauge does not work on the dash
-did an oil change
-did a seafoam spray when I had the truck running.
-seems to run hot after a very short time: coolant starts to steam and bubble into the overflow after only 5 minutes or so. It is full of fresh coolant.
-the spark plugs are wet, and smell like gas when i take them out to do my "trick"...other wise plugs look good and have a healthy spark.

Thanks in advance...I'm learning a ton about engines trying to figure this out!

JH

Welcome to the forum

2.9l engine I assume

You have a blown head gasket or cracked head, from your comment about bubbling in overflow tank

But I doubt thats the no start issue

You can use "Clear Flooded Engine" to see if you have fuel leaking into the intake after shut down

All fuel injected engines have this
Turn on the key
Press gas pedal down to the floor and hold it down, all the way
(key on, gas pedal to the floor = turn OFF fuel injector)

Now crank engine over, holding gas pedal down to the floor
Engine should NOT start or even fire, injectors are off
If it does fire then fuel IS leaking in, if fuel pressure regulator is new then an injector is leaking, not closing all the way causing engine to flooded out as fuel pressure pushes fuel into intake.

The Clear Flooded Engine should dry out spark plugs enough for restart, vs you pulling them out each time.

As soon as you release the gas pedal injectors will start, or if engine fires enough to reach 400rpms then computer will exit Clear Flooded Engine on its own
I use this every morning on my high mile 4.0l, get the oil circulated before I release gas pedal so no "dry starts"

You could disable spark, do Clear Flooded engine and then pull out spark plugs and look at which spark plug tip was wet, thats the one with leaking injector


Test for blown head gasket, it won't show up on compression test until it gets undriveable, if one cylinder was just a little lower than the others then that would be the one, but very hard to tell until breach get larger
The Test
Cold engine
remove radiator cap
fill rad to top
Start engine
Watch for rad to overflow, it shouldn't, you might get a burp at start up
Let it idle for a few minutes, make sure its topped up all the way
If it starts to over flow then Cylinder gases are being pumped into cooling system thru blown head gasket or cracked head.
The gases displace coolant in the heads and so push coolant out of the radiator.

With cap on, system will hold pressure to 16psi then cap opens and sends coolant over to overflow tank, the gases will make there way to high points in the cooling system, top of radiator is one of those points, so constant pressure keeps rad cap open and the gases start bubbling up in the overflow tank instead of coolant.
Heater often stops blowing HOT air because its hose are high points and air/gases in those hoses can block flow
Temp gauge, if it was working, would go to above 1/2 the drop down and then go back up as the air in the heads is pushed out and then returns.
It could be the coolant is leaking back in to the cylinder when engine is off, and if its intake valve is open then intake would get flooded with coolant vapor causing the no start.

You can do the Glove Test, search here, I have posted it quite a few times
This can confirm the problem 100% and also ID the cylinder with the leak.

Thanks RonD,

This helps a lot. I've got a mechanic buddy stopping by in the next few days, so we will look into it.

I'll keep you posted.

Thanks again!

JH