So if you guys remember im the one that had the goofy gas gauge that showed im getting way better mileage than i used to. Well i still am. Thats not the problem. K.. my voltmeter has been flickering to almost no voltage and then back to where its supposed to be.. sometimes its stops about half way between dead and the middle where it usually is. My lights dim and stuff when it happens too. Im pretty sure this is all being caused by a bad negative battery cable cuz a few times i had no power at all.. wiggled the cable.. everything came back on. by the way its a 89 b2 2.9 5spd 4x4. Ok so theres all the background. My problem im writing about now is that my oil pressure and engine temp gauges are being weird. They will sit right in the middle where they always have, then start moving up to the point id be overheating and whatever happens when oil pressure is too much would happen. But nothing happens. A few seconds later theyre down to where my engine needs to warm up and i have no oil. Still everything is running ok. Last of all my engine does seem to be running a little rougher than it did a few weeks ago, and it lugs a lot more than it did. Like 4th going 35... before it wouldnt grumble, it would just kinda go.. not much acceleration but thats cuz these engines are wimpy. Now it grumbles more like it would if i was in 5th going the same speed or even slower. Soooo.... main thing i needa find out..... are the two problems related and do i need to worry about them, fix em immediately, ignore em, what? Sorry this was so long, but its kinda gettin me worried cuz i have 153,000 miles and im starting to think my engine is going bye bye, and i needed to let you guys know all the details so you dont hafta ask me later. Any info would be appreciated.

 

So much on these vehicles depends on that ground cable. For example:
Dash gauges are only as good as their connection to ground. A bad ground and who knows what you'll get from them.
Engine management (aka EEC-IV system) references it's sensor signals to ground. A bad connection between the computer and the negative battery cable will throw the whole engine management system off, which causes the engine to run rough.
In this case, I would suggest you take care of what you know to be wrong (the negative battery cable) and see how many of the other things are fixed with it.

 

K heres another question... first of all im sorry.. its the positive cable ive had to wiggle a few times. But... i checked the negative and now im confused. The negative cable is probably two to three feet long ending in a ring shaped connector. The ring goes to absolutely nothing... its sitting there in open air. About half way between the ring and the battery it goes through about a quarter inch long tube thats connected to the frame rail and im assuming thats my ground. My real question is, where is the end of the cable supposed to go???? So if you can help with this question or the one that started this thread.... that'd be great. Also thanx shorty.. that makes me feel better that you think its just the connections themselves.. those are easy to fix. I hope youre right.

 

That should be connected to the block.

 

ok ken.. i'll do that. But, the end on the battery is old and crappy so im gonna get a new cable tomorrow. With the new cable do i need to get the one from the dealer that goes thru the tube on the frame, or just a regular new cable straight from the battery to the block? Also ken, you got any advise about the gauge thing?

 

Im with mrshorty on this, get the ground cable fixed and make sure that the grounds from the back of the engine to the fire wall are good. Get the grounds fixed and I bet that the guages start to work right. A good ground cable to your bolck is all you need ,make sure that you get one that you can conect the 2 small ground wiers too 1 goes to ground on the front right by the battery and the other grounds the computer to the bat. Good luck.

 

You should have the cable grounded at the frame too, you might be able to remove a spot of insulation and crimp it into the frame clamp. The gauges rely on the engine being grounded, so I'm with mrshorty and gray.

 

Ok guys, i replaced both battery cables. The negative i just grounded the frame where the old one was. At first it ran fine, gauges still going goofy, but other than that it was fine. I was ready just to leave it and ignore them. Then i started it back up and it took longer than normal to get it to start. Then i started it up a few minutes later (i was running errands with my brother) and it didnt even want to crank at first. It just did the click like when the battery is dead. Couple tries later i got it to crank but still didnt fire. Finally got it to fire. Then the last place we stopped it cranked for a while but wouldnt fire. Then it wouldnt crank at all. So i wiggled all the wires that have just been replaced n stuff.. got her to crank but wouldnt start. Couple tries later i got it running again, but it would still cut out for a split second. Now when it cutting out for a second, my radio was still fine so i know the dang thing is at least getting power. WHAT IN THE HECK DID I SCREW UP?!?!?!?

 

If you didn't attach the negative cable to the engine block, then you need to make sure the engine block has a good ground to the frame. Because of rubber engine/transmission mounts and such, the engine by itself doesn't have a good path to ground.
Did the negative battery cable you buy have "pigtails?". In stock condition, the negative battery cable has a pigtail to ground the EEC computer directly to the battery post. If your cable doesn't have pigtails, then the computer (at least) needs to find another route to ground, and that should be inspected to make sure it has a good path to ground.
Another thought is to make sure the connections for the new cable are tight.

 

Dont worry about grounding your battery to the fram with the big neg cable. THAT ONE NEEDS TO BE GROUNDED TO THE ENGINE BLOCK!!! There shuold be 2 small wires that go to the neg. side of the battery 1 to groumd 1 to the ground to the ECU.like mrshorty and kenoo said.Get your truck running right then will fix the guage problem if you still have one.

 

K heres the news. Turns out i really was running hot... never boiled over though. Anyway my thermostat was barely opening so i took it out, replaced the gasket, put the housing back on. Im running WAY cooler now. And yes, i know i gotta put one in before the winter. Anyway my oil pressure is still sky high. Ive got the gauges to stay at least most of the time. They flicker here and there and the engine wants to die here n there, but mostly its running ok. Problem now is, when i took the thermostat out there was oil in the coolant on the ground. I know it could just be from oil and gunk built up on the outside of the engine and the coolant picked it up, but lets say it didnt. You guys say overheating these 2.9's WILL crack the heads. Heres what i need to know now.
1. What about overheating but not so much as boiling over like in my case?
2. assuming the oil is not from the outside of the engine does that mean i did crack the heads?
3. what do i do about the high oil pressure?
4. what do i do if i did crack the heads???

 

You don't have to boilover to crack the heads. If the oil is from outside then the heads may not be cracked. Don't worry about the stock gauge reading until you deal with the heads, then put a real gauge on it, the stock ones arn't very good.

First thing is don't run the engine until your sure the heads are OK, if you do you can kill the bearings. Check the oil for coolant, will look like chocolate milk. Then pressure test the cooling system. If your still unsure, remove the heads and have them magnafluxed.

 

Well heres whats going on now.... It is still hard to start and will only fire if it is completely cooled down, like at least a few hours. It runs like crap, my gauges still are going nuts, and i double checked all the wires that i replaced and they are fine. Ive done everything i know how to do. Its sitting in the far right bay in the shop about a mile away and im waiting for them to call me. Thanx for all the help though guys. I'll let ya know how it turns out.

 

You'll never guess what the shop just told me... my computer is completetly gone. They couldnt get it to respond at all. They are still wondering how i drove it down there. Anyway they wont know prices or anything until tuesday, but they said the last computer they replaced was $200 for just the computer itself. But it'll be worth it if i can get my bronco back in shape the way it was when i got it.

 

I got one for a auto 89 BII thats good $150.00 + shiping if you went it.I took it out of my 89 when I did the tranny swap.It will work on a manual shift but will show some shift codes{ no check engine light}.Sounds like you need to check the EEC ground to battery to make sure its good .