Bronco won't stay alive

[Nelson and Hudson]

I fixed the above issue by adjusting the TPS after following the instructions I found on the web.
Now it'll run and won't die...within 30s. The 2 new big issues I cannot seem to figure out are: Dying (sometimes) after driving and then coming to a stop. And not being able to smoothly shift.
When coming to a stop like a red light and sitting there for a bit, the engine will shudder, and stall unless I can catch it by giving it a throttle. If it does die, I just put it in neutral, start it up, and then back in drive. The other issue is its shifting. When going up a hill, my foot is on the throttle for a while and it won't shift into the next gear for a few seconds (5-10s). I could use some advice as I'm getting disheartened I cannot resolve this issue on my own.

 

[Nelson and Hudson]

Did some more tweaking. It runs a lot better. I drove around the area at around 45mph, and didn't die or hesitate. Felt confident enough to take it on the freeway and nothing happened for a little while. Then the acceleration started loping again. I wouldn't move my foot but the engine would feel like it was losing gas, sputtering, and then got a huge surge of it. As if all of it came out at once. This would go on for some time.

I'm going to try to bore out the TPS holes slightly so I can get the TPS Voltage to 0.9v and keep the idle at 700rpm. (https://www.therangerstation.com/for...stment.196011/)(https://www.therangerstation.com/for...-voltage.7852/). I could also try taking out my ECM and cleaning it with IPA. I want to check my FPR as well as put on a fuel pressure gauge in the compartment so I can check that it is within spec.

 

[bobbywalter]

sounds like the wrong pcm calibration or a wiring harness issue.....like you have a manual trans pcm in an auto...egr/non egr

does the heater circuit on the o2 sensor circuit have power? does it still have a functioning converter on the exhaust?


what are the actual vacuum readings? map line condition?

 

[Nelson and Hudson]

does the heater circuit on the o2 sensor circuit have power? does it still have a functioning converter on the exhaust?

I'm not sure how I would test either of those. But either could be a possibility, I haven't investigated them. The MAP line is in fine condition. I'll get a Fuel pump/Vacuum gauge from Harbor Freight and test it. Any advice for checking the vacuum?

 

[bobbywalter]

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actron.com

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there are resources like these that may help better then i can explain.

 

[Nelson and Hudson]

@bobbywalter I appreciate it. I also could not get the O2 sensor off because it's in a weird position where I cant get a wrench on it. Any tips?

 

[bobbywalter]

well.....sometimes that is an unwinnable fight out here in the rust belt.....you have to destroy everything and start over. hard to say what you are looking at. redondo...i assume is in cali,,,

i have specialized sockets for them and they still strip out.



most testing you can do without removal...i usually hack up junkyard harnesses to make my own little breakout harness for testing....just plug it in inline with leads long enough you can easily meter them in situ

 

[Nelson and Hudson]

I *think* I've fixed the dying issue by tightening the throttle cable so it's more responsive. It's not the TPS fault, I thought by getting it closer to 0.9v that it'd run better, but after swapping out a different TPS, it gave me a voltage of 1.2v and ran the same. So I've concluded that the TPS is not the problem so long as it's within range. However, the fact that it seems to get worse over time gives me a clue. Fuel pressure? Vacuum? Heat messing with an electrical item? I need to do more testing.

 

[Jazzer]

I have the same year engine in a Ranger.

You can get to the O2 sensor from just downstream on the y-pipe, between the pipes. You’ll be facing the front of the truck. IIRC, there’s enough room for an 1/8th revolution per open end wrench swing, took me I think 52 repositions.

If it hasn’t been changed in 80k miles or so, I’d just go ahead and replace it. They wear out and can give some puzzling symptoms. Bosch is the best brand to use, IMHO.

Good Luck!

 

[Dustin_89BII]

Hey, damn sorry to hear about all the troubles you're having! I've had a hellava time with my 89b2.

Have you tried to pull engine codes for these issues? Going through the engine code procedure, where you blast the throttle when it tells you is key to getting a head start on troubleshooting. If their are no codes, god help ye! There are soooo many little things that could be creating the symptoms you're experiencing.

A few ideas:

Checking fuel pressure at key on engine off, as well as when running is a good idea. I think the '87 was equipped with the duel fuel pump set-up, and I know a lot of guys on here have trouble with them.

I think I had trouble with wires getting too hot at one point, as well as spark plug cables being too parallel to each other -- that is to say, it could also just be some weird simple thing thats messing you up. So, the process of elimination is your friend. And I see that you've done a ton already. I hope the ol' gurl makes it thought!

I'd also check the IAC -- the can on the side of the upper intake. Theres a procedure for checking the wiring coming into the unit as well as the checking the functioning of the unit itself by hitting it with 12v power to see if the air valve actuates. They often get dirty and don't regulate air consumption correctly when the engine is cold. I've also heard on here that most aftermarket TPS and IAC's have a tendency to not work correctly in the B2 and that you need genuine motorcraft parts or maybe Hitachi or something?

Anyway, good luck to you. I'm glad there is still an active group of enthusiasts on here!

 

[gaz]

Did some more tweaking. It runs a lot better. I drove around the area at around 45mph, and didn't die or hesitate. Felt confident enough to take it on the freeway and nothing happened for a little while. Then the acceleration started loping again. I wouldn't move my foot but the engine would feel like it was losing gas, sputtering, and then got a huge surge of it. As if all of it came out at once. This would go on for some time.

I'm going to try to bore out the TPS holes slightly so I can get the TPS Voltage to 0.9v and keep the idle at 700rpm. (https://www.therangerstation.com/for...stment.196011/)(https://www.therangerstation.com/for...-voltage.7852/). I could also try taking out my ECM and cleaning it with IPA. I want to check my FPR as well as put on a fuel pressure gauge in the compartment so I can check that it is within spec.

Why would you want to clean your PCM with beer???

 

[xsaylr]

Did some more tweaking. It runs a lot better. I drove around the area at around 45mph, and didn't die or hesitate. Felt confident enough to take it on the freeway and nothing happened for a little while. Then the acceleration started loping again. I wouldn't move my foot but the engine would feel like it was losing gas, sputtering, and then got a huge surge of it. As if all of it came out at once. This would go on for some time.

I'm going to try to bore out the TPS holes slightly so I can get the TPS Voltage to 0.9v and keep the idle at 700rpm. (https://www.therangerstation.com/for...stment.196011/)(https://www.therangerstation.com/for...-voltage.7852/). I could also try taking out my ECM and cleaning it with IPA. I want to check my FPR as well as put on a fuel pressure gauge in the compartment so I can check that it is within spec.

Fella I believe I have the exact same prob on my '88. I went after it for a while over the summer but never did get it fixed. Main similar symptoms being random power loss while driving, and it wanting to die at stops. I don't even recall everything but I have new Motorcraft TFI & MAF, fuel filter, no vacuum leaks, cleaned throttle body thoroughly. It's real discouraging, id really like to drive it. I considered replacing the 2 pumps with 1 in-tank pump, but haven't yet. Please post if you figure anything out

 

[Nelson and Hudson]

I just finished my finals so now I can go back to trying to troubleshoot it more. I need a list of things to check, otherwise, I might get it towed back home and take it to a mechanic. I love driving my B2 and I wish it were working again. It's one thing to fix a problem, knowing what the issue is, it is another thing entirely to try to fix a problem with no idea why it's there in the first place.

List of things I could check:
The 02 sensor: Like @Jazzer said, it's in a weird position so if I can get it off I can try cleaning it before reinstalling it and see if that alleviates my problems. I suspect that the wires connecting it are causing issues as they're exposed partially. This feels like an electrical issue due to it being so sporadic and unpredictable.
Fuel Pressure: My father thought it was the FPR that was the issue so I checked if I smelled gas, I did but that wasn't enough proof for me. He insisted I replace it so I did, but even that did not fix the issue.
TPS: The TPS is my main suspect. I messed with it and it hasn't been the same since. I've tried countless attempts at getting it back to where it should be but nothing has seemed to fix it. I wonder if the timing and the TPS need to be in sync, where if you mess with the TPS you have to get the timing back in place with it.

If anyone can offer a list of things I should check. (Mainly electrical) I would greatly appreciate it.

 

[Nelson and Hudson]

I did some messing around in the engine bay. I got it to run long enough to drive around my neighborhood. I got down to a parking lot and tried to start it up again. The issues returned; would die a few seconds after starting, and sounded like it was struggling. Did not get any codes. Miraculously I was able to get it back home. It runs and idles fine. But then will intermittently die. The only thing I can think of that I truly messed with was the PCV valve and the spark wires. What happens if my PCV valve does not have a good suction or leaks? What happens if the spark wires are in a weird position that will cause this? Or am I barking up the wrong tree? I need some advice, but I definitely cannot drive it 45 miles home.

 

[Uncle Gump]

Before going any further...

What us your fuel pressure? Have you actually tested it?