Going crazy...

[Marty86]

1988 BII 4x4 5spd

First off, this is my father in laws truck. He's left it at my house to figure it out.

Been having a couple issues with the truck starting. You can drive around for a while, park, go in someplace and come back out and it won't start. Then, once you get starting, it's likely he'll just die when you are on the road heading to the next place. After waiting 10-15 minutes it'll finally start back up and you'll be fine until the next time.

This is what he told me. When I got it, it immediately started and didn't give me any issues. I took it for a test drive, no problems. The next day I had a doctor visit, so I drove it there. Came back out, wouldn't start. (I was in the Doctor's office 45ish-1 hour). After a bit of trying, attempting to see if the fuel inertial switch was tripped, it finally fired off.

Drove about 8-10 minutes, and was on a bridge overpass heading (stuck in traffic) and it dies. Luckily this is one of the few bridges that have a full width shoulder. I push it over to the side (thankfully on the downward slope...would have been a pain otherwise) and try to start it a couple times. No go. After about 10-15 minutes, it finally starts. I jet over to the next exit and put in $20 of fuel just in case it was too low (fuel gauge hasn't worked in years, we just use mileage and it's never left us stranded)

Got all the way home, no problem. On the drive back, I noticed the temp gauge was stopped between C and the line below N. I knew this couldn't be right, and remembered was like this on my test drive from the other day. So I changed out the coolant temp sender. Now it QUICKLY shows it to run hot...at least, it sits between N and O. Typically it's sat right at M.

After it cooled down, I popped the cap and reved the engine. It sucked in water quickly, and it came back when I stopped revving it. So I'm thinking the water pump is working. Since I drove it over 45mph, and still got hot, I am assuming it's not the fan clutch. Father in law said he recently replaced the thermostat, and I confirmed this (and resealed it too, so it doesn't leak)

Any thoughts on what this could be? He needs to get the BII back so he doesn't have to drive his diesel every day (diesel owners know the $4.29 gal pain here in Texas...)

HELP!!!:icon_twisted:

 

[unoleisu]

I'll assume your truck is stock 2.9L? It sounds like you have a TFI Ignition Module issue to me. ( no run issue)
On my 87 BII (2.9L), it is A little (1"x 3") grey rectangular thing mounted on the back of the distributor, toward the firewall. They tend to get too hot because of their location, so close to the engine, and start acting like that, until total failure. There is a write up somewhere on here about relocating it so this won't happen. I have done the relocation and it works so far. Short term, you can get another and swap it out. After markets don't seem to last as long as OEM.

It has two bolts on back that hold it in place, and sometimes require a special tool to remove it. I have read that there are a couple of possabilities of the type of bolts being used, (torx, or metric bolt) The metric bolt doesn't leave enough room in the hole for some sockets to fit in, thus the special tool is required (available at most auto supply stores) I have found that there is a third option, being phillips head screw. I strongly sudgest you get a mirror and a light, lay across the top of the engine, (put some sort of padding on it, or you get funny bruises across your chest) and visually verify which kind you have. (I spent a good 20 min. pissing myself off trying to get the special tool to work after trying the torx, only to eventually discover the phillips heads)
I went to a salvage yard, (on an unrelated mission) and picked up a couple spares for future emergencies, But have a new after market one on mine now.
Hope this is helpful.

 

[chrwilkins30]

around me the special tool was only at orileys, autozone or advance did not carry them, I think it cost me 6 bucks but that's the only way to remove it. The size is a 5.5 IIRC. the shoulders of the sockets are to think to get into the really small hole. and there are little caps on the holes and mine where a real pain to remove.

but it definaly sounds like TFI like unoleisu mentioned.

 

[Marty86]

I replaced the TFI last year...so maybe I need to get another one?

Any thoughts on the "almost overheating"?

 

[Bronco_Chuck]

The thing about the stock gauge's is that they only give you rough estimate. I would get an aftermarket temp gauge to see if it is actually running that hot or if your gauge is just inaccurate.

 

[Charles]

Check/wiggle that little black fuse looking connector that goes to the battery. It should be right behind the battery. I think it goes to the negative terminal.
I had almost the same problem you are describing with mine. sometimes it would start, no problem, other times, never would turn over. Once it even died while driving it. I knew something was loose when I went over railroad tracks and the vehicle would jerk.

I eliminated that connector and never had the problem again.

 

[Jspafford]

If you replaced the sensor that operates the guage in the dash it is probably just showing it running 'hotter' because you now have a clean contact with the wire to the guage. Best thing would be install a mechanical temp guage. Pretty simple. Goes in where the old guage probe comes out.

Did he get all the air out of the cooling system when he did the thermostat?

My guess is that it is not almost overheating. It is either operating at normal temp or something is not working and it just plain overheats. There is not usually an inbetween.

TFI modules have been known to act up worse when they get hot. Maybe connected if you are infact overheating. Do you know of anyone with one of those point and shoot thermometers?

I would guess you have a sensor reading wrong and causing the truck to run rich, and therefore flood out. You would notice a drop in mileage though.

Any codes?

 

[Marty86]

Good idea, I'll clean out the wire, I didn't think about that *doh*

I am willing to say he didn't when I replaced the thermostat. I need to pop off the housing though, looks like it's leaking a tiny bit too (like 1 or 2 drips, not enough to be a big deal). Truck leaks oil enough, so I don't want to add to it, lol.

I'll have to see if I can find someone who has a old code reader. I'll check back after the weekend, thanks folks!

 

[Marty86]

Well, came out to the truck Thursday afternoon to leave, and it wouldn't start. Took the wife's car, and tried Friday afternoon as well. Still wouldn't start. I played with it today, and it starts if I put starter fluid or fuel into the throttle body (I don't recommend fuel because you can fry electronics, but I dropped a tiny bit in...)

I'm towing it to a local garage I trust, and hopefully they can run the codes and confirm for me it's the TFI. I'm running out of time to test it, and I just need it running so I can work on my other dead bronco, lol

I'll let yall know what they find!

 

[unoleisu]

It's cheaper to just swap out the TFI than tow it and pay for diagnostics. I Got one for $10 at a salvage yard, and tried it. Then went and bought a new one, and kept the salvage one as a spare.
Good luck, though. The last local guy I used was supposed to be very reputable, and I ended up over $3000, and 3.5 months in the hole, and my tranny still had the same problem. Hope you have better luck.

 

[Marty86]

I've actually been using this guy for 3 years, and he's been great. We have a sort of understanding, I do the majority of my own work, but occasionally I need some help and so he doesn't charge for diagnostics (for anyone, actually) and I'll tow it myself, so it won't cost me anything.

I'll let yall know!

 

[adsm08]

High pressure fuel pump.

 

[Marty86]

High pressure fuel pump was bad, replaced it, found the TFI to be bad.

Still won't start. What am I doing wrong here? Turns over perfect.

 

[Marty86]

I started researching again and thought the intertia switch. But after reading this (http://www.therangerstation.com/tech_library/InertiaSwitch.html) I don't think so.

I think when I turn the key on, I can hear the low pressure pump. But even with the new one, I am thinking I'm not hearing the (new) high pressure one. I've got a 86 bronco on at the inlaws I'm thinking of grabbing parts from (it runs, but I need this as a DD). What should I grab?

 

[adsm08]

Check for fuel at the rail. If one of the pumps has power, they both should have power.

Then check for spark at the distributor. If you have fuel and fire, something else must be wrong.

 

[xr75er]

what adms08 said.get a fuel pressure tester and check what pressure you have on the fuel rail. one pump on, both on. thats how it's set up. I went thru all this and had to change out 2 computers. started with the TFI, HP fuel pump, in tank pump, relays, one rebuilt computer, then last code was "no fuel signal" took the computer back to Auto Zone and got a warranty replacement and she's been runing great since October 2010. Hope you get it figured out. :icon_thumby:

 

[Marty86]

Yeah it's going to the shop tonight, so I'll let you know what happens. The thing that sucks is that I need it for my daily driver, but I'm working so much I can't spend time on it, lol. Hopefully they can figure it out. and get us on the road. I'll let yall know what we find....

 

[Marty86]

Apparently it's the fuel inertia switch. Can't I just bypass (delete) this switch instead of replacing it?