Help, engine misses randomly

I have a 89 4.2L Wrangler, recently I somehow lost the Oil filer cap and a some oil was lost inside the engine compartment lightly covering the block, distributor cap and wires and the air filter cover. Since then it will randomly miss 1 to 3 cylinders whilst driving, when it occurs there is a notable loss of rpm and "go". On a couple of occasions whilst in 1st gear it has missed completely and stalled.

I replaced the air filter and cleaned down the surfaces, I also took a look at the distributor wires and all seemed clean... what am I missing here, help! Thanks in advance for your reply's.

Reply to
Stevil
Loading thread data ...

Reply to
L.W.( ßill ) Hughes III

It's oiled.... Oil conducts.

I would figure you will find oil under every spark plug wire boot on both ends.

You could try having the engine running in the dark and spray a mist of water on the plug wires and distributor cap. This will show you where the spark is leaking from.

The oil also likely got into the distributor cap via the vacuum advance linkage opening so you should open up the cap and check in there too.

I also would figure the power plug on the coil is oil saturated.

Carb cleaner spray or brake cleaner will wash a lot of that off.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Just make sure you do that with the engine off, and that it is dry before you start it. Carb cleaner and leaking voltage are a bad combo.

Reply to
Stupendous Man

Thanks fellas, I gave everything a good clean and replaced the rotor, distributor cap, igniion wires and spark plugs just because I was there... now it runs perfectly, thank you for all your suggestions. Now ALL I have to do is replace the rear main seal so it stops leaking oil on my drive way, LOL!

Reply to
Stevil

Actually you would likely be 'Way' better off changing the leaky valve cover gasket that lets oil run straight down the back of the engine that imitates a rear seal leak quite well.

To test, warm up the engine and run a clean rag across the rear of the head below the valve cover. If you find oil, you have found the leak.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Reply to
L.W.( ßill ) Hughes III

Reply to
RoyJ

In article , RoyJ wrote: #What Mike said. Anyone with the 4.2 knows how to change out the #$$##@@!## valve cover seal. Sometime next week you will be asking if you #should use the cork gasket or seal it down with RTV. :)

If you ever get your 4.2 replaced, order a engine with a head that takes the metal valve cover instead of the plastic one that warps and spews oil. RTV worked just fine for my metal valve cover...

/herb

Reply to
Herb Leong

The older heads can be drilled and tapped for the bolts to hold on the metal cover. The YJ's came that way and the later CJ's.

I am running a head with no bolt holes in it now. The cover is only held on by two nuts on rocker bridges up top and a 'really' cleaned surface with a skim of RTV and cork sandwich. After 5 years it is just starting to seep oil, no drips yet.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06
formatting link
(More Off Road album links at bottom of the view page)
Reply to
Mike Romain

Reply to
L.W.( ßill ) Hughes III

Excellent advice gentlemen, I'll give that a go at the weekend and see if I can't save some money. Thanks again.

Reply to
Stevil

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.