As some of you guys out there may remember, I once posted an issue I had with the ignition system of my truck, which solution involved replacing it with a 5 pin ECU. Everything was going on great, until 2 weeks ago when rain hit my city. First, the truck busted a valve rocker arm, thus I was having no cut-off if I removed the spark plug wire from cyl. no. 3. I got confused, went to a mechanic who found out about the rocker arm and we replaced the damaged part. The truck ran great, until the next week, when it rained again.

Now the truck's symptoms are that the engine has a very smooth and fantastic idle, as if nothing was going on, but if I engange gear, especially reverse, the idle goes all wrong, I mean, it tends to cut intermittently as if a spark plug would be faulty, but they are all new. Usually when cold and with gear engaged, the idle is good but if I request power from the engine, i.e. to take off the engine misses, and the more i step on the gas, it sounds like even more spark plugs are missing, and as the truck gains speed, the problem ceases, so if I go constantly at 50MPH for example, I have no problems until I step on the gas to pass a car or if I keep the gas the same and I go over a higher road (let's say a bridge) the truck fails.

The vacuum advance on the pickup-coil distributor I have has never worked on my truck and it was working fine until the rain, so I don't think it's an advance problem, though I might be wrong. Another thing I did was to remove the spark plugs and all of them except for the one with the new rocker arms (which came out perfectly clean) came out dark at the bottom, with half-clean electrodes. One of the spark plugs was all dark. The residue looked like way too-burned, oil-like gum that came off with a stroke of wire brush. By the way, on the area this severed spark plug is, there is a sound like a leaky exhaust manifold, but I haven't confirmed if it's really the manifold.

Due to the condition of the spark plugs, I'm starting to think that the rest of the rocker arms are in bad shape and they need to be replaced. What do you guys think?

 

I would give it a tune up first.

 

I think you should check your distributor cap and spark plug wires for corrosion and wear.

K.I.S.S.

*edit* - Yeah, what Charlie said. I had the page open for an hour before I responded, so I didn't see his reply.

 

Well, dizzy cap and cables are new, as well as the spark plugs, but I haven't changed the oil. Anyway, this thing is very weird, and as I said, one spark plug comes out all oily. Looks like I have to check the rest of the rocker arms.

The other day I took the valve cover off (the left one) and some of those rocker arms are kinda loose, I mean, I can slide them a very very little, but not rock them. Aren't they supposed to be under the pressure of the rod that comes from the camshaft and the valve spring? As I repeat, just one or two (one is actually from the faulty spark plug) can be moved and the rest can't. Can my problem be related to this?

 

I may be way off here, but when you broke the rocker arm initially, it seems like some water got into your engine & it hydrolocked to some degree. When you are running at speed & water gets in there, it causes damage such as bent push rods, broken rockers, etc. At idle speed, water may just cause the engine to die until it dries out. This could have caused many if not all your push rods to bend, causing the remaining rocker arms to seem loose, because the push rods are not as long after being bent a bit. Also look at the botom end - make certain nothing drastic hapenned such as a hole in the block. This does not happen often, but I have seen it in cars & trucks that have an aftermarket air intake that is set very cose to the bottom of the frame so a splash of water has little issue getting in. I saw a cavelier that lost the back of the block where the oil filter attatches after my friend drove into some shallow water after a hard rain - the hole in the bottom end was big enough for me to reach in & grab the crank with both hands not even scraping the sides of the tatered block. BTW - never buy a cavalier! I would also suspect an electrical short in some part of your igjnition system. Good job on adding new wires & cap, but they are only part of that curcuit. Keep in mind that wires can look fine, but when they are beyond 20 years old, they can have cracks in them that are hard to see but allow water to ground them out against the chassis, body or frame. Simply identifying these wires & adding extra insulation like convoluted tubing can help on the cheap. I hope this helps.

 

Thanks for the reply, peshewa.

Your comments make a lot of sense to me, yet I'm sure the block is intact, as I haven't seen a drop of oil on the floor where I park the truck at home, and the undercarriage is as dirty as it's always been. However, I never thought of the push rods, yet I think that if they were bent, I could rock the arms, when I can only slide them side to side on a very small distance. I'm not saying you're wrong, because when I took the valve cover off, maybe the position of the engine caused me to detect the sliding rocker arms but didn't allow me to rock the arms (if they can be rocked on any other position of the engine).

You're also very right on the ignition part. I used some old wires when I put everything together with the 5 pin ECU and since I didn't have enough cable that day, I patched some others there on the meantime until I got money to put new wires in, but I forgot about that since the truck was working fine. Anyway, I'm going to replace every single wire and I'm also thinking on soldering every part where cables match to terminals or other wires and see what's what, thanks a lot for the tips.

 

Hydro locked motors bend connecting rods instead of pushrods.