2.3L ('83-'97) Intermittent No Start on 1995 Ranger 2.3L

[95RangerBoss]

Hello all.

I recently have had an issue with the truck not starting when warm. But it is not at all consistent. Sometimes it will fire right up with no issues at all. But then other times after the truck has been running and I go to start it up again, and it will stutter, but not start. This could go on for 20 minutes or so until it will fire right up and keep driving. I originally had some trouble with the fuel pump and have replaced it. Fuel pressure is strong. It seems to be some sort of spark problem, but with it being so intermittent, it is very odd. If I don't turn the truck off, it runs perfectly. Any help?

I have a couple of videos of the issue at this Google Photos link: https://photos.app.goo.gl/UURBvzhSNQdfRyqh6

Thank you all!

 

[RonD]

I would define the problem more with 50/50 test
Get a can of Quick Start/Starting fluid(ether)

Next no start, spray some into the engine
Try to start
If its starts and dies its a fuel problem
If it doesn't start then its spark problem
50/50 no guessing


Warm engine with warm outside air = easy to flood an engine

 

[95RangerBoss]

Will do that. I already have a can of starting fluid, so will do.

Jesse

I would define the problem more with 50/50 test
Get a can of Quick Start/Starting fluid(ether)

Next no start, spray some into the engine
Try to start
If its starts and dies its a fuel problem
If it doesn't start then its spark problem
50/50 no guessing


Warm engine with warm outside air = easy to flood an engine

One thing to note: it usually fires up and dies first. Or will fire and run super rough for about 3 seconds and then die. I haven't had a chance to do the starter fluid test yet.

 

[95RangerBoss]

So I am thinking that my Ranger is getting flooded because of the afternoon heat in AZ (103+ degrees)

Reasoning:
- The truck rarely fails to start unless it is quite warm out
- The truck only fails to start when warm
- The truck only intermittently fails to start under these conditions
- After 10 mins the truck will start up perfectly fine and run smooth.

What can I do to test this flooding theory? And what could I do to prevent it?

 

[RonD]

Press gas pedal down 1/2 way then crank engine to start, this will let in more air to off-set more fuel if its flooding out

Throttle sensor does not set fuel flow, many think that, TPS just gives the computer a "heads up" when driving that "driver" wants to slow down or speed up
You can pump the gas pedal with key on engine off until "your FOOT is blue in the face" and not one drop of fuel will be released from an injector, lol

ECT sensor could cause bad startup fuel mix
And IAT(ACT) sensor

Air/fuel mix is based on 14.7:1 ratio, and its a WEIGHT ratio not volume
14.7 pounds of air to 1 pound of gasoline
14.7 grams of air to 1 gram of gasoline

Its why fuel injectors are rated in pounds per hour, i.e. 14lb/hr, or 19lb/hr
Gasoline weight stays fairly constant

Air is the bigger deal, its weight changes A LOT!!!
And "hot air rises" why?
Because its lighter than cooler air, its how Hot Air Balloons can fly

100deg Air is very light so engine can easily flood out
Add that to just shut off warm engine that heats up the intake while it sits under that hot hood................
Call heat soaked


ECT sensor tells computer how not the engine is
IAT(ACT) sensor tells the computer how hot the air is

IAT = intake air temp
ACT = air charge temp
It can be called either one

 

[scotts90ranger]

It very well could be air temp related, these things have some dumb numbers in the calibration for spark but don't know what it would do with that for startup... I know above 90F outside temp sitting at a stoplight then accelerating from stop the spark advance moves to after top dead center instead of before like it should be... at least on my '97... I've talked about experimenting on that but haven't yet...

My '97 starts hard here and there, I was convinced it was injectors but I put some new ones (rebuilt apparently but still, they were bought from Amazon as a set...) in a few months ago and it didn't change that much. If I go to WOT to clear it out it helps... something is going wonky but it always starts so I forget about it until it happens next time , at 200k it deserves to have some quirks so I'm not going to complain too much...

 

[frozenrabbit]

Do you have a tach? When it's not starting and cranking, if the tach doesn't show any RPM when cranking, it's a bad crank sensor. Chased mine for months, random start/ no start. Crank sensor had hair line crack.

 

[scotts90ranger]

Reasonable thought, the crank sensor on a '95-01 is a bit simpler than a '89-94 but VR sensors do go out too... if there's any little metal shavings on the tip of the crank sensor (VR sensors have magnets in them and the crank sensor is external...) that would NOT help...

 

[95RangerBoss]

Sorry for not replying here. No, I unfortunately don't have a tach. Tried to install one once, and that was a fail.

 

[95RangerBoss]

Just a quick update here: I figured this out! It was the fuel pump relay that had gotten fried by the Phoenix heat and was sticking. Replaced that relay, no more issues. Hope this helps someone out some day!