yes i know it is an 89’ ranger and yes it is a bit of a rust bucket, but i would like to get a couple more years of light duty work out of it. i cannot pin what the problem part is. i can start the truck with no problem if the local temperature is above say 60 degrees. if the air temp is below 50 and the humidity is high it will not start. i have been successful in starting it at cooler temps sometimes but now it has just given up completely. the last couple of times i was able to start it at cooler temps it would start normally and then after about 30 seconds begin to misfire with a type of electronic stall for a half second and then recover for about a second then stall again, recover again and so on until it would just completely stall about a minute or so later. i replaced the intake manifolds sensors to no avail and suspect either the catalytic converter or electronic ignition parts in the distributor. any help to pinpoint the failing part in this case would be greatly appreciated. oh yea, it is a 2.9 liter V6 ohv ranger xlt. thanx for any help
I would check into two things. First the IAC valve…its on the top of the intake plenum on the left side as you look at the engine. This is what gives you Idle control…Faster when cold…SLower when she warms up. SHe might be stuck in the Warm position…which means it doesnt flow enough air when cold to keep your idle up higher rpm levels.
The other item…and im NOT certain this engine has this…but I was thinking the Cold Start Injector… Damned if I can recall if your engine has a Cold Start injector. I think I recall seeing the wiring diagram for that engine and I saw Cold Start Injector wiring diagram…so look into this.
Look into that IAC tho…I KNOW you have one of those…LOL. It could be gummed up with crud…either try cleaning it…or buying new or from a salvage yard. Could be the culprit.
When was the last time a secondary ignition tune-up was performed?
This means everything from the distributor cap to the spark plugs.
If you can’t remember, that’s where I’d start.
Since you state this seems to occur with cooler temps and high humidity you might consider popping the distributor cap loose the next time it won’t start and check for any moisture in the cap.
What can happen is that a warm engine will draw in moisture after it’s shut off if the atmospheric conditions are right. WIpe out the moisture (if present) and hose it all down with WD-40.
The cool, damp conditions are common here and can sometimes lead to the inside of headlamps (same principle about warmth…) and underneath the hood looking like it just rolled out of a carwash.
Many years ago I used to have a Mercury Sable 3.0 that was prone to the moisture problem even with the rubber distributor cap shield in place.
Honda and tester have given you some excellent suggestions, to which I would add the temp sensor. I could be wrong on this for this vehicle, but of the ECM is unaware that the engine is cold it won’t drive the iac motor for high idle nor activate the cold start injector.
I’m humble enough to realize I’m suggesting general thoughts with no knowledge of '89 Rangers, but hopefully the thought if not applicable to this vehicle will stimulate an idea from someone who is.
thanx to all for your comments and input. the distributor is not suspect, i have replaced it during an earlier time with a similar problem and it worked. this time is different and it has no moisture in it. the ecm is a good suspect and probably it will be replaced with a rebuilt distributor swapout soon. i still am interested in any knowledge about catalytic converters and the o sensor in it. thanx again.
A failing catalyst would result in power loss as rpms increase and the sensor at the catalyst has no influence on cold starts or cold driveability. Only if the catalyst were severely blocked would it cause a problem getting the engine to start and temperature would not have any effect in that case. Te sensor at the catalyst is the O2 sensor and its function is to monitor the oxygen in the exhaust to indicate the performance of the engine for minor recalculations in the air fuel mixture AFTER the engine is started and has run long enough that the O2 sensor works. On an '89 model that could take several minutes and even if the O2 sensor were unplugged it would not result in a significant loss of power or cause a driveability problem. There is no post catalyst O2 sensor on an '89 model to monitor its performance.
As for the distributor, I would strongly suggest that you remove the cap and inspect the cap and rotor for ‘flash’ which would be chaulky discolorations in the plastic that indicate secondary ingnition arcing to ground within the distributor. The arcing will cause your problems and it is usually caused by failing plug wires.
thanx to all again and as my typing ain’t so good, yaknow i fergot to type cap after distributor in my last post. so the distributor cap is in great shape and the plug wires have only about 30,000 miles on them. the frustrating part is that the truck will now start and run about a minute or so and then begin the stall, run, stall, run and so on with a large amount of firecracker popping kinda like backfire and then a total stall. probably will discover the fault by replacing all that has been suggested until the faulty part is presented by a normal engine operation. many thanx again.
Underhood temps can cook wires in 30,000 miles, depending on conditions, placement and so forth. I would start easy with a normal tune-up as I can afford the stuff, start with plugs, then wires, then cap, then rotor (if equipped) and so forth. You’re certainly not “throwing parts at it” as some folks might say, any vehicle can benefit from a tune-up. While you’re doing this simple stuff, I would go over the connections from the battery to the engine, ground and all. This vehicle is 26 years old and funky stuff happens, why not do the basic stuff while you’re already dirty. Good luck! Rocketman
Just a clarification; it’s the temp sensor that I suggested looking into and possibly changing, not the ecm (engine control module). If the temp sensor is bad, changing the ecm won’t help.
I also got the impression that you have the ecm confused with the ignition module in the distributor. The two are different things with totally different functions. Apologies if I misunderstood.
The moisture inside the dist. cap comment was based on your comment about humidity. If moisture is not an issue then what about the ignition module? This truck should be a TFI model and those TFI modules are notorious for failing.
Have you pulled the DTCs on it yet just to see if something is there? That’s not the final answer as those modules can be problematic without setting a code. Just wondering if there might be something related to a missing or erratic PIP or SPOUT signal from the module.