This 94 Bronco with 142,000 miles was given to me by my neighbor whose owned it since it was new. Said it started running bad when his sister drove it and then it sat in his driveway for a few years until he gave it to me a month ago. It would start if I put fuel in the intake but not on it's own so I replaced the rust filled fuel tank, fuel pump, sending unit, fuel filter and it still wouldn't start. I have great rail pressure now and the injectors are getting the signal to fire (verifited with noid test set). So I was installing new fuel injectors today and I found the passenger side valve cover loose so I know someone was looking at the valve prior to me getting it. II found the intake valve pushrod on #8 bent. So I don't know if the Bronco started running bad from fuel issues or this bent pushrod. I"ve considered the pushrod was bent after the rig sat for so long and the valve was possibly stuck from the bad gas in the truck or it could be the the pushrod bent then the fuel system took a dump after sitting for so long.

When I was cranking it the oil pressure would come up and when I would put fuel into the intake it ran like it was missing but I figured that was from me dumping considerable amounts of fuel into the intake. I also noticed when I removed the upper
intake manifold the #8 intake tunnel was black with what looked like oil.

Wha'ts my next step? I understand it may be a lifter or a valve issue, right? Anyway to determine which without tearing it all apart? I'm pretty sure that's where this party bus is headed but I'd like to avoid it if possible. I was tempted to get another pushrod and put it in there and turn the motor over with the valve cover removed to see if I can see anything. Thoughts on that?

 

Yeouch, that is one very bent pushrod.

It's pretty hard to say which actually caused the pushrod to bend, since it wasn't diagnosed right away after it started running badly. But, it sounds like something is gummed up. Either the valve is stuck, or the lifter is stuck. I've heard where you can loosen valves by popping down on them with a rubber mallet. Lifters are a little more involved since you have to remove the intake.

In the mean time though, you could get another push rod to replace it and then turn the engine over by hand. If you get to where that particular valve is about to open and you suddenly feel resistance, you can both use that to diagnose what's not moving correctly, and you can stop applying force. Unless you have a huge breaker bar and just crank on it despite it not wanting to move, you're not going to damage anything.

Either way, you'll need to free up what's sticking before you fire it back up. If it's varnish, even getting it to free up and move won't be enough. The varnish will need to be cleaned/broken up. Maybe try pouring some Marvel's Mystery Oil down all of the valve stems and let it soak.

 

Thanks, that's sound advice. I poured some Marvel's Mystery oil into the intake for the cylinder (upper intake is still removed) in hopes if it's a stuck valve it may loosen it up. I'm going to give it a few days to soak in and hopefully that's it but it not then I'll yank the lower intake manifold and look at the lifters.

 

I actually just talked with the previous owner whose owned it since it was new and apparently it was running fine they quit driving it 5 years ago. it does appear the #8 intake valve is stuck closed as it wouldn't budge when I tapped it with a rubber mallet. All the others did move so hopefully a few days of soaking in Marvel's Mystery oil will free it up.

 

the oil in the intake is probably due to a bad PCV valve. there is a Ford TSB stating the PCV hose should be routed to the middle port on the upper intake so it better distributes those oils. Once that valve frees up and you get proper movement you might consider doing a seafoam treatment, change the oil after wards and start running a Delo 15w40 oil and run the snot out of that motor. plan on another oil change after say 1000 miles. Be sure to run a Purolator, wix or motorcraft oil filter. Anything else just wont give the necessary engine protections.

good luck

 

Haha, I'm in Bend also, we live out in Sundance Ranch! For the PCV, do you mean route it to the port where all the vacuum lines are tapped off of? The valve did free up last night so I'm off to Napa to pick up another pushrod and turn it over by hand to see how things shake out. I've got two cans of seafoam standing by as well as some Delo which I use in my dirt bikes n' Cummins, I should just buy stock in it.

 

right on , I am out 27th/reed mkt.

yes about the reroute. google search should show some pics if i recall. you might also consider new spark plugs after the seam foam. if nothing else check them afterwards.

 

There is joy in Mudville! After installing the new pushrod and verifying the valve did move, I reassembled everything, said a quick mechanics prayer in which I apologize for any misgivings in judgement and language during the whole process and cranked it over. The Bronco fired up so quickly is scared me. She proceeded to produce a biblical smoke show while she burned off the Marvel's Mystery oil but after that it ran so smooth it was scary considering it hadn't ran in 5 years. I changed the oil and added Seafoam to it which I will run for a little while then change that out. I'm going to change out the rest of the fluids in the diffs, tranny, transfer case and antifreeze this week. The wipers, tail lights, brake lights and blinkers didn't work so by changing out the headlight switch and multifunction switch I got everything working as well.

The PCV routing was already taken care of as I guess it was a late model 94 and has the updated upper intake manifold so it's not dumping it exclusively into the #8 cylinder.

Thanks to everyone for the help, great insight and advice!

 

Awesome to hear! That has to be a great feeling. And congrats.

That's cool that the PCV was already dealt with. One less issue on your list.

Now route a good long road trip and take it for a drive and clean that motor out. It needs to get good and hot and let that cleaner run through it.

Have fun!

 

Thanks, that's the plan but I'll be doing the shake down drives in small steps to make sure things like the water pump aren't going to let loose in the middle of nowhere.

 

Great to hear you got it running. What are your plans with it? lift, tires etc..? There is a Deschutes County 4 Wheelers meeting this sunday afternoon at 5pm at Fat Tuesdays. if you are into wheeling this is a good group that i go out with at times. they are very welcoming.

 

I'd like to level it out but Im not going to build a beast like yours. Just one I can drive in the woods and not worry about scratching it up, I may come by for one of the meetings to see where you guys go.

 

there trips vary, many are out on wide trails. for sure check it out some time.