86 Ranger Stalls When Warm


misterjesse

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The problem I'm having is that my truck will stall when it's warm out and the truck's been running for a while. Stop and go traffic is particularly likely to cause it to stall. Feels like it's out of gas, sputtering, no power, bucking and dying, but it definately has gas . Usually after 15 minutes I can drive it again, though it needs some coaxing and often dies again on the way home. Often it's happened after I've driven it a bunch, stopped to run an errand, and then driven it a little more. It's never happened in the morning. I've brought it to a mechanic but the problem didn't manifest while he had it idling. He recently gave it a tune-up and replaced the alternator (not specifically trying to solve the stalling problem, although I had my fingers crossed that it might).

I should mention that the temperature guage doesn't work.

I'm not very knowledgable about engines, I guess I'd like to be able to fix it myself but more realistically I'm looking to at just diagnose it.

More info: engine is a 2.9 Fuel Injection. Mechanic said fuel pressure was good, but that doesn't mean much since he never got to test it while it was having problems.

Am thinking I should get a fuel pressure tester and drive around with it taped to the windshield to see if it's fuel pressure or electrical, will update if that adds information. What else should I try? Truck also leaks oil a bit, from the head gasket, often smokes and smells for this reason, but I love it and want it to be reliable. Thanks so much!
 


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misterjesse

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I just did a little more searching on the site and read about TFI modules and the problems they cause when they get hot. I think I ought to start there! I'll update soon, any advice still very appreciated, especially as to how to remedy this TFI situation if that's what I have.
 

Millster

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Your truck sounds like mine. I've replaced the TFI, replaced the high pressure fuel pump, rewired the connections to the computer (which helped, kind of) and it's still doing the same thing. Heck it even leaks from the valve covers. :)

Here's where mine is at right now. When it's warm outside, I can get about 1/2 hour out of it before it starves out and dies. And for the first time, I got the pressure tester on it when it died. 10psi immediately after death and 0psi thereafter. All fuel pumps are RUNNING, but clearly fuel is not going where it should. Not saying yours is the same problem, may well be the TFI as one of mine DID go bad. But I've replaced it twice. I would definitely look into fuel pressure when it's acting up. My bet is you've got issues there.
 

mendozamm

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I had the same problems too. I replaced tfi, and nothing. It would warm up and die, 15 min later im cruising down the highway. I replaced my relays on my firewall. I guess 22 years was enough for those. Havent had any more trouble:yahoo:
 

Millster

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I had the same problems too. I replaced tfi, and nothing. It would warm up and die, 15 min later im cruising down the highway. I replaced my relays on my firewall. I guess 22 years was enough for those. Havent had any more trouble:yahoo:
I've likewise replaced my relays (one of which was replaced with a manual switch) and while it's BETTER, it's still not great. I played "motorvehicle roulette" again today by driving my Ranger.
Prior to relay replacement, when it died, the high-pressure pump would not even spin. Now, it spins but produces no pressure. I have appropriate pressures at KOEO and idle, but pressures diminish with throttle and disappear as the truck begins its "death cycle".

I'm obviously going to start with the inertia switch since it's easy to access and can be problematic but my suspicion really lies in the accumulator. I believe it's become so encrusted over the years that it causes issues with both the in-tank and rail-mount pumps. One can't push enough, the other can't pull enough.

Anyway, that's my story, if it helps anyone. Sounds like we're all having variations on the same issue and hopefully between all of our experiences, we can find something that works for everyone. :)
 

RyanL

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Man I'm glad that mine is a '89, not '88 and older because the fuel delivery issues are 10 fold with the older generation. All I have on mine is a fuel pump, fuel pump relay, inertia switch, fuel filter on the frame rail, and a FPR on the fuel rail. That's it, no accumulator, multiple fuel pumps or mulitiple gas tanks with switching valves and all the other crap that goes along with those systems. Without being able to check out the OP's vehicles personally, my $ would be on the TFI, BUT if it is bad I would think that he would be getting codes for it like I did and I don't even think that mine was that fried. You can check the codes misterjesse by using a jumper wire, turning the ignition to the "on" position (engine needs to be warmed up by the way), and counting check engine light flashes. You may only get code 11 a couple of times, but it doesn't hurt to try. Here is a link to how to do it (scroll down to the MIL method): http://www.therangerstation.com/tech_library/OBD_I.html .
 

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Thanks to all of you for the replys! I replaced the TFI this morning, haven't died yet but don't think that means anything yet. I think I'll just pretend I've diagnosed it and fixed it until it fails and then start over again, probably by getting a fuel pressure gauge and trying to field test it. What exactly would I be looking for in that case?

One question: Millster wrote that the pressure read "10psi immediately after death and 0psi thereafter"... does that mean it's the fuel pressure or would it do that anyways simply because it died?
 

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One question: Millster wrote that the pressure read "10psi immediately after death and 0psi thereafter"... does that mean it's the fuel pressure or would it do that anyways simply because it died?
That sounds about right to me. When the engine dies, the fuel is cut off shortly after (at least that's how I think it works with most vehicles). I think that if the ECU doesn't sense RPMs, it'll cut the fuel. As far as hunting for a decent fuel pressure gauge for the vehicles, good luck. I went to autozone a while back to rent one - it was like $200 or some crap and it didn't even have the right fitting (they were all larger ones which look like AC fittings). I guess newer vehicles have larger fittings. I went to a smaller store and they had one which looked like the correct fitting included in the kit, but they wanted like $150 for it. It was kind of steep for something which I would probably only use once so I passed. I looked around on the net and found some, but most had sketchy reviews at best. I eventually found one at a Salvo auto parts store for $40 which didn't have fifty fittings which I would never need (it just had 2) and it was a name brand.
 

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One question: Millster wrote that the pressure read "10psi immediately after death and 0psi thereafter"... does that mean it's the fuel pressure or would it do that anyways simply because it died?
Sorry, that didn't make much sense.
After the engine died from apparent fuel starvation, I hooked my pressure gauge up. KOEO fuel pressure was 10psi. As soon as I tried to crank the engine, it dropped to 0psi and would not come back up no matter what I did. The frame-mounted pump was definitely running and SOME fuel was being moved because every time I removed the gauge to make sure something hadn't gone wrong with it, fuel would squirt a little bit. There just wasn't any significant pressure behind it.
 

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Sorry, that didn't make much sense.
After the engine died from apparent fuel starvation, I hooked my pressure gauge up. KOEO fuel pressure was 10psi. As soon as I tried to crank the engine, it dropped to 0psi and would not come back up no matter what I did. The frame-mounted pump was definitely running and SOME fuel was being moved because every time I removed the gauge to make sure something hadn't gone wrong with it, fuel would squirt a little bit. There just wasn't any significant pressure behind it.
Sorry, I didn't understand the "thereafter" part in your post. Yeah if you tried to restart it and you weren't getting any fuel pressure it sounds like a fuel problem (or a wiring issue in your case). If your ECU relay was that far gone, maybe your fuel pump one is shot too (you might even have two fuel pump relays with your system). It's also not unheard of for a fuel pump to run fine when cold, but give out when it gets hot.
 

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Sorry, that didn't make much sense.
After the engine died from apparent fuel starvation, I hooked my pressure gauge up. KOEO fuel pressure was 10psi. As soon as I tried to crank the engine, it dropped to 0psi and would not come back up no matter what I did. The frame-mounted pump was definitely running and SOME fuel was being moved because every time I removed the gauge to make sure something hadn't gone wrong with it, fuel would squirt a little bit. There just wasn't any significant pressure behind it.
I've had issues with the grounds to this pump before, it will run but it won't generate pressure because it's getting crappy voltage. I've got a spare just in case but the original framerail pump (with 315K miles!) works just fine. It feeds my 4.0 swap quite well.
 

misterjesse

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Update: As I mentioned earlier, I did replace the TFI, but my luck has not changed. If anything, the problem is getting more pronounced, as in more frequent break downs, possibly longer interval before the engine will cool off enough to run again. (Or maybe it just seems longer.) A friend saw me stalled out and pulled over and suggested it might be "heat lock," a new term to me... basically he said that when the fuel line isn't properly shielded from the engine's heat, fuel can vaporize in the line causing the car to run out of gas. I tried a quick and dirty experimental fix by wiring some pieces of flashing between the engine and the fuel lines, but this didn't prevent me from breaking down twice on the way home, again. I'm starting to seriously contemplate ditching this vehicle.

But on the positive side, the problem is happening often enough that I might be able to drive it around my mechanic's neighborhood until it starts acting up it so he can check it out... I agree with RyanL that buying an expensive fuel pressure tester to perform one single test is a bit steep! I'll definately post again if I ever get to the bottom of it, pretty wild how many paths of inquiry are involved in this.
 

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Update: As I mentioned earlier, I did replace the TFI, but my luck has not changed. If anything, the problem is getting more pronounced, as in more frequent break downs, possibly longer interval before the engine will cool off enough to run again. (Or maybe it just seems longer.) A friend saw me stalled out and pulled over and suggested it might be "heat lock," a new term to me... basically he said that when the fuel line isn't properly shielded from the engine's heat, fuel can vaporize in the line causing the car to run out of gas. I tried a quick and dirty experimental fix by wiring some pieces of flashing between the engine and the fuel lines, but this didn't prevent me from breaking down twice on the way home, again. I'm starting to seriously contemplate ditching this vehicle.

But on the positive side, the problem is happening often enough that I might be able to drive it around my mechanic's neighborhood until it starts acting up it so he can check it out... I agree with RyanL that buying an expensive fuel pressure tester to perform one single test is a bit steep! I'll definitely post again if I ever get to the bottom of it, pretty wild how many paths of inquiry are involved in this.
I would almost bet my left nut that you're not experiencing vapor lock (what your buddy was calling heat lock) unless someone re-routed some of your fuel lines or exhaust so they touch or almost touch. Back in the carbureted days it was much more common, but with the fuel pressure that these things have it's very unlikely. Now it will act like vapor lock if the it's not getting the right fuel pressure for whatever reason. Like I mentioned before, it could be either fuel pumps, a bad relay, a bad ground (like the other guy mentioned), fuel filter or accumulator clogged, etc, etc. Did you ever get a chance to pull the codes yet? It's supper easy to do with a little jumper wire and just count the check engine light flashes (you'll get the hang of it eventually). You're not even entirely sure that you're dealing with a fuel issue yet. Maybe it's not getting any spark or something. When the ignition dies it can seem like it's running out of fuel.
 

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m y 89 is doing th same thing.new filter,fpr,relay,still good running in th morning,then when its hot sputter n dies.if i reiene pressure at th rail it sprays air out with th fuel. takes like a minute to stop spraying.
 

CORanger

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These problems sound just like mine... IF anyone has further information I would like to hear about it! This is my only vehicle and I am going away to college and really need to get it fixed so I will have transportation.
 


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