Firing On all Cylinders?

[kptfj60]

What is the best way to diagnose if the engine on my 86fj60 is running on all of it's cylinders? Someone told me that it sounded like it wasn't. I use it as a dd and it does run somewhat rough at idle but otherwise I've not noticed an other major changes.

 

[NocalFJ60]

A good place to start is pull the plugs and see what they all look like. A compression test would also be good to rule out a engine issue. It sounds like you got a vacuum leak or some other issue causing it to run rough.Does it always idle rough no matter what?

 

[kptfj60]

It has actually started running more rough lately. I have actually had a series of issues as of late. and am starting to think that the engine has just about had enough. It over heated a number of times this winter and I'm hoping that this didn't cause major damage. I'm not sure though. I can hear a pretty good exhaust/manifold leak that has gotten worse. Haven't checked yet if it is manifold or exhaust. Also my oil filter has a large amount of oil in it. So I fear the worst. I'm not sure where even to start. I feel like I'm chasing age and should just cut my losses and rebuild. However, I've been planning on a full resto/build and am not financially ready yet and feel like rebuilding the engine that isn't even the one I want in there in the long run might not make sense. Oh well, sorry I'm frustrated. As I stated this is my dd.

 

[NocalFJ60]

Check the PCV valve vacuum line and make sure you have vacuum at idle. If the vacuum line is clogged, then it could cause oil in the air filter. This could also cause the crankcase pressure to go up which is not good on the rings. Also the oil in the air filter can get sucked up by the smog pump which will not make it happy. The overheating is not good and could cause head gasket leaks.

Just start checking things and post up and you can get it running good again or else figure out if the engine is going.

You got a compression guage? I would start there. Pick one up for $25 or borrow one from someone.

 

[Tinker]

"Also my oil filter has a large amount of oil in it"??????

Didja mean air filter (& Nocal figured it out)?

 

[kptfj60]

Sorry-I did mean air filter.

 

[mtb_rider]

As far as checking it for a miss, pick up a set of plug wire pullers (the ones that are insulated on both ends) fire it up, and start pulling wires one at a time from the dizzy cap, and see if you find one that doesn't drop the rpm when you do it. This is a quick, easy way to see if you have a miss. Then if you, do you can go about pulling plugs, doing compression test, etc. But oil in the air filter tells me you have other issues as well.

 

[kptfj60]

Well NoCal- I took your advise and pulled out the old compression guage. (had to go to the parents to get it) Sad to report.
#1 170
#2 165
#3 15
#4 15
#5 165
#6 170

Not very good news. I don't know what I'm going to do next. Looks like she's officially been down graded from dd to project truck.
I was hoping it would hold out another year and half until we moved to New Zeland. I was going to do a total strip down and rebuild upon my return. Guess I'm in the market for a new rig.

 

[NocalFJ60]

Well NoCal- I took your advise and pulled out the old compression guage. (had to go to the parents to get it) Sad to report.
#1 170
#2 165
#3 15
#4 15
#5 165
#6 170

Not very good news. I don't know what I'm going to do next. Looks like she's officially been down graded from dd to project truck.

Sorry to hear the news. That is very low. It might be a head gasket leaking between the cylinders. You could leave the plug in one (3 & 4) and do the other one. I am not sure if that would work though but it might bring up the compression. A leak down test would tell you where the leak is and you could feel the air coming out the other spark plug hole if that was it. Did you have all the plugs removed when you did the test? You can pull the valve cover and inspect the valves & push rods and check valves too. Sounds like your rings went and the crankcase has a lot of pressue and pushed oil up into the air filter.

 

[kptfj60]

The rings are what I'm scared of. They're what are holding me back. I can handle pulling the head and having it reground and the valves done. Then I could repair the head gasket and everything would be great but if it's the rings that's a whole other story for me. Then I might as well be in for a full rebuild. Right?

 

[kptfj60]

My one hope is this as far as the rings/oil in air filter. I checked out my pcv valve and during idle it has good vaccum. How do I know this? Because it was just dangling there in the engine compartment. The grommet that holds the valve to the tube that come out of the block is gone. I wonder if that could be causing alot of the pressure/oil in air filter issue? I'll probably pull the head anyway. We'll see how the rings are doing then.

 

[kptfj60]

Yes I had all the plugs out. What is a leak down test?

 

[mtb_rider]

You need a Leak down tester and a air compressor to do one. It is basically a manifold with two pressure gauges on it. You hook your air line to one end, and the gauge on that end shows pressure in (usually around 90psi with most compressors), and the other end has a hose coming out like your compression gauge does that you screw into the S/P hole. You then rotate the motor around by hand to TDC on the cylinder in which you have the hose screwed into, and see how much pressure it holds in comparison to the pressure going in. You will then also be able to determine where you are losing the pressure, either by hearing or feeling the air coming out. In this case, probably the #4 cylinder (if testing number 3) but also, if air is coming out of carb or exhaust pipe, then it means you have a bad or leaky valve, etc. I do leak down tests alot on outboard boat motors. It is much more accurate on a 2 stroke then a compression test is.

 

[John McVicker]

Well NoCal- I took your advise and pulled out the old compression guage. (had to go to the parents to get it) Sad to report.
#1 170
#2 165
#3 15
#4 15
#5 165
#6 170

Not very good news. I don't know what I'm going to do next. Looks like she's officially been down graded from dd to project truck.
I was hoping it would hold out another year and half until we moved to New Zeland. I was going to do a total strip down and rebuild upon my return. Guess I'm in the market for a new rig.

Might still be just the valves. In the likely event you don't have a leak down tester, you can still gain additional info by doing a dry..then wet compression test. Put 3-4 squirts of oil in the cyl & retest. If the numbers stay the same..most likely a vavle problem. If the numbers go way up.. most likely rings.

Did you watch Ian on Extreme last week ? He gave a demo.

HTH John

 

[kptfj60]

Thanks John-
I'm going to give that a try.
Don't have cable but was buying the project saggin wagin' episodes from itunes. They never finished up the build! At least not yet I think.

 

[rover67]

make sure the valves are adjusted.......