Ranger intermitant starting problems

I have a 94, 4.0L manual trans 4x4 XLT Ranger. For a couple of years now when the weather is warm every once in a while the truck wont start after being driven. It will crank but wont start until it has sat for about 10 to 15 minutes. This has been annoying but not a real problem. Recently it started something new. It will start but will idle very slowly even if I step on the gas pedal. I can shut it off and start it again and it is usually fine. Some times when it wont start I start swaping the relays around and the truck starts fine. I dont know if moving the relays made a difference or it just took long enugh. Any ideas?

Hi NTM,

I don't have an answer for you, but I am having the same starting problem.
It has steadily gotten worse in the last six months. It will crank, but not start. Let it sit for a while and it starts and runs fine. This happens in any weather and usually after it has sat and cooled off. It will only start about 50% of the time now. It is tough to diagnose by the dealer because it doesn't happen when I need it to...lol. I sure hope you get some answers here, but I've noticed it can take quit a while to get help sometimes. I just replaced the cluch slave cylinder (inside transmission) and alot of brake work (including master cylinder), so I am not afraid to fix it myself if I knew what was wrong. Just trying to replace parts can get expensive. I'll continue to monitor this post. Good luck!

Kyle.

I have a 94, 4.0L manual trans 4x4 XLT Ranger. For a couple of years now when the weather is warm every once in a while the truck wont start after being driven. It will crank but wont start until it has sat for about 10 to 15 minutes. This has been annoying but not a real problem. Recently it started something new. It will start but will idle very slowly even if I step on the gas pedal. I can shut it off and start it again and it is usually fine. Some times when it wont start I start swaping the relays around and the truck starts fine. I dont know if moving the relays made a difference or it just took long enugh. Any ideas?

I have a 94, 4.0L manual trans 4x4 XLT Ranger. For a couple of years now when the weather is warm every once in a while the truck wont start after being driven. It will crank but wont start until it has sat for about 10 to 15 minutes. This has been annoying but not a real problem. Recently it started something new. It will start but will idle very slowly even if I step on the gas pedal. I can shut it off and start it again and it is usually fine. Some times when it wont start I start swaping the relays around and the truck starts fine. I dont know if moving the relays made a difference or it just took long enugh. Any ideas?

Did you check for spark and/or fuel when it wouldn't start?

I'll have to put some tools in the truck to check for spark and fuel. It's never happened at home.

when it wont start, the easiest thing to check is turn on key and listen for the fuel pump to cycle. this will at least eliminate a fuel prob. if the pump works fine then i'd start checking coil packs. i think that year used coil pacs?

I have never been able to hear the fuel pump run. I understand that the pump is inside the fuel tank. The next time the truck wont start I will try having someone else turn the key while I listen near the fuel tank.
Thanks

Hi NTM,

My son switched the FUEL PUMP RELAY with the A/C WOT RELAY and he claims that it runs better and hasn't had the starting problem. It has only been a day, but better than before. Only time will tell. You can find those relays under the hood in the Engine compartment fuses box. If this works, then I guess I'll just buy another relay. They only cost between $6 and $9, depending on the brand. I suppose the next question would be...has he tried the air conditioning....lol. Well he is a high school teenager and claims he can't afford the fuel to try it. I'll have to slip him a couple dollars and give it a try soon. Hope this helps.

Kyle.

I've tried switching the relays before and the truck started but the problem came back. If the relays are as cheep as you say I'll try replacing them. My AC hasnt worked for years so it isnt much of an indicator. I should see if I can take the fuse/relay box apart and check the condition of the terminals.
Thanks

Hi NTM,

Its been 5 days now and the truck is still starting and running just fine. Hope that works for you.

Autozone show the following for the relay:

RELAY - FUEL PUMP for a 1994 FORD TRUCK RANGER 2WD
GP-SORENSEN MR76 $8.99

Kyle.

Tomorrow I will change the relays and try to check the condition of the contacts. I'll be using the truck all weekend, so I'll let you know how it goes.
Thanks

These engines will run without a crankshaft position sensor but they won't start without one. You may have an intermittant sensor.

Make sure you check the ground wires a loose connection will cause starting problems.

A friend of mine had a somewhat similar problem with the addition that it would sometime quit under no particular circumstances in the worst place.
It ended up being the inertia switch or more accurately the harness going into it. The harness is not long enough going to the switch so it's under strain which causes the terminals to overheat which in turns leads to a bad connection.......Mike

the 94 3.0L V6 does not have a CPS or coil packs, it has stnd plug wires, distributor and plugs. I'm having the same issue with my 94, I decided to replace all sensors until I find the cause, so far I've replaced the fuel pump, filter, plugs, wires, cap, rotor, Mass AF sensor, TPS, IAC valve, ambient air sensor. Still starts with low idle and idles up to normal in about 10 seconds while blowing black smoke out the exhaust. When I feather the throttle it will die or bad hesitation like a bad power valve in the Holley carbs. Runs fine once you smoke the clutch to get rolling down the road until you get to the next red light. Sometimes dies and won't restart without flooring the pedal like it's flooded. Yesterday I noticed while at steady speed (45mph) the temp gauge would climb to center, CEL would light for about 5 secs and go off and the temp gauge would drop, repeated this several times. I replaced the temp sensors (2) a couple years ago but thinking the one that controls the CPU is wavering ($40 sensor - 4pin) Rock Auto shows it as ACDELCO Part # 1551108 SWITCH,ENG COOL TEMP ENG SHUT DN.. (shut down, hmmm)I'm trying my local CarQuest for it and will post the results. Actually I'll replace both since they are next to each other.
--Mike