I don't have any compression on #1. So I started taking stuff off to pull the heads off. When I got the valve covers off the rocker is very loose where I can jiggle it on #1. Does this indacate anything besides needing the heads re-done. The bolt that holds the rocker on is tight also. So is the slack in the valve and spring or on the push rod side. It is a 1990 model bronco.

 

Since you have zero compression in cylinder #1, Its a safe bet that the valve under that rocker arm is stuck open. And if you are going to pull one head to have one valve fixed, it just makes good sense to do both and deal with all of the valves. Just be aware that having the upper part of the engine overhauled and regaining compression on top can often lead to the need to do the bottom (rings) as well. Old weak rings will deteriorate more quickly if the valves are sealing like new above them.

 

With that valve off of the cam lobe, is the valve closed? Is it sticking up as much as other valves that are closed? If so, then it would seem the problem would be on the other side of the rocker. Spin pushrod with thumb and index finger while looking down into the hole in the head with a bright light. Is the pushrod bent?

I worked on an engine once that had no compression in one cylinder, and low in another. Oil didn't raise it, and it passed a leakdown test. Found a badly bent pushrod, the pushrod had come up and out of the lifter, came down and popped the spring off of the lifter that held the lifter together. So it all popped apart, and would not open the intake valve at all. The other cylinder had a bent pushrod on its intake, but it was able to open its intake valve some, so it had low compression.

 

If the valve is stuck open. Is there any way to un-stick it to get it moving ? I also pulled the intake so I could look at all the pushrods and none of them is bent.

 

The engine I refered to had one intake valve stuck slightly open, and I assume the one with the really bent pushrod and come-apart lifter was stuck completely closed. I used a mallet and tapped/struck the top of the rocker over the end of the stuck valves. I may have used a larger punch to direct the force more accurately, I don't remember anymore. I made sure that the piston was away from the top of stroke in each cylinder that I did that to.

Both were intake valves, stuck I believe due to carbon buildup on their shafts and then being parked for a long time. But these pushrods were bent, showing that the valves wouldn't open or wouldn't open all the way, therefore bending the pushrods when the cam came up on lobe. If the pushrod is NOT bent, and the lifter is NOT collapsed, then I wouldn't think that you have a stuck valve, but eyeballing it should tell.

Since you have the valley open, you could pull out and inspect that lifter, and the cam lobe too, if it still has a lobe, or if it's worn off. If lifter appears okay, and lobe has lift, you could use a hand oiler and pump up the lifter through its little oil hole on the side, pump oil in real good, and then put the lifter back in, then turn the crank with breaker bar and see if valve opens and if the major slack in the valvetrain on that valve is gone. If it is okay then, I would suspect that lifter, or maybe the oil hole in the block bore for that lifter is plugged up.

 

will a e4od tranny and transfer case out of a 1996 f-250 gas engine bolt up to a 1990 351w in a bronco . the bronco now has a e4od .

 

The answer - Yes. Out of curiosity, how will that help your valve-train issue?

 

It won't. Lol. I'm rebuilding the motor and I found a this tranny cheap enough to have a extra if it will work just to have IF I need it. Thanks for answering my question anyways. I will try to stay with one topic. Lol

 

Not a problem. I was just trying to figure out how one helped the other. Actually I'll be the FIRST person to tell you that if you are going to keep the E4OD slushbox, find another one for when the one you have breaks. Its not a question of whether and E4OD is going to fail but WHEN it will.

 

Since u brought it up...I never have liked the e4od. What tranny could I use in its place ? And if I change to another what will it do to the electronics in the 1990 bronco if anything ?

 

You can lose the E4OD in favor of anything that will bolt to a 300, 302, or 351W. If you remove the E4OD you will need to either leave the MLPS (Manual Lever Position Sensor) attached to the wiring harness for the old E4OD and leave it in the "overdrive" position or (and this is my preference) you can pull the MLPS and pop a 400 ohm resistor between the signal output and signal return pins of the MLPS connector. If you actually do a swap at some point, just ask us, we can give you the pin-out for the MLPS connector. IF YOU FIND A COMPLETE DONOR truck that has the same engine (351W I believe you said) as your Bronco, you can swap EEC-IV computers and skip this process all together because the whole MLPS adaptation is only done to keep the EEC-IV computer happy.

I personally, have gone the extreme route of removing the E4OD and installing a ZF S5-42 (the heavy-duty 5-speed from the F250-450 trucks). The M5R2 (M5OD) is OEM 5-speed that was available in the Broncos and F-150's at the time. Of course the swap to a manual does entail swapping pedal assemblies for the brake/clutch pedals and adding the clutch and master cylinder. However, since the M5OD was available in these trucks, there are just a couple of covers to remove to mount the MC in the firewall.

The AOD will work if you want to keep the overdrive automatic. However it needs the throttle valve (TV) cable and the linkage so it will shift properly. A complete setup from a donor will work. Adjustment of the TV cable can be tedious.

The venerable C6 is always a popular option although you will lose your overdrive with this 3-speed. It is arguably the most reliable strongest automatic Ford used in the light trucks and it is very easy to maintain.

There are other transmissions that will also work. These are just some of the most common swaps. Again, as long as the unit will bolt to the back of a 300, 302 or 351W AND it has a 4WD tailhousing it will fit into your 1990. If you can find a donor truck with all of the peripheral parts you will be better off since the E4OD crossmember is unique to the E4OD. The ZF and the M5 use the same crossmember. The other automatics you will have to ask someone with more intimate knowledge of an actual swap.