A few days ago I used the tech on here to swap out my passenger side valve cover. I have an 89 V6 4WD truck, and it isn't running right now that I've got the engine back together. It runs like one of the plugs is fouled or firing out of order.

I replaced the PCV valve and hose when I put on the new cover. The only thing from the tech I didn't do was to put the RTV sealant down before putting on the new valve cover. I didn't have as much room as the guy who did the tech, and working the cover back in there would have gotten sealant everywhere.

I checked the air intake to TB hoses for cracks because this sounded like a breathing problem to me, but they're all in good shape.

It sucks to have my ride down and out. Anyone have any advice?

 

Is it not running due to no spark or no fuel.
I'd suspect fuel -- if so, you have to flow air past the AFM to fire the fuel pump. You can try by-passing the AFM switch (see 4crawlers page) and see if it runs.

 

Make sure all the vacuum lines are hooked up right, and not plugged-up or cracked/leaking.

I would suspect fuel/spark(esp. if it wasn't running at all), but you're not as likely to have gotten the fuel lines crossed during the reinstall. And unless you inadvertently bumped a plug wire or something, you shouldn't have had to diconnect any ignition components to get at the valve covers.

 

I looked at some pics, and I'm fairly certain the vacuum lines are all in the right place. I'm not sure how to be 100%, but a lot of them are different sizes and the others I did the best I could from before pics. I should have marked them all with tape I guess. I found more than one leaking vacuum line in my quest to fix this. I either snipped the ends or replaced the hoses, and it did make it run better. It obviously wasn't the root of the problem, though, because it's still acting up when revved.

To clarify, it starts and runs. I can drive it around. When you hit the throttle there is a bit of lag and more shake than normal with a bit of extra noise. Standing in front I don't hear anything out of the ordinary from the engine. It sounds like a spark plug or air/fuel problem, but I didn't mess with the plugs and only did simple removal/reinstall of air intake components. There was some carbon buildup in the barrels of the air chamber which I left alone. I suppose I could have knocked a chunk out when reinstalling, but I don't think it would make it act like this.

Do I need to prime the fuel pump or anything like that after removing fuel lines from the plenum? Is it possible that an air bubble got trapped in there somewhere?

I don't even know where to go from here as far as troubleshooting goes.

 

Can you post a pic of youre engine bay?

 

Wait... so you didn't reseal the valve cover? Could be a vacuum leak.

 

I don't think it sounds like a fuel issue, simply because if it is idling with some sense of normality it should be getting fuel. You could try bleeding your fuel system -

unhook the return line that goes back to your tank (I forget which one it is but I believe it is right by the AS Reed valve, close to inlet fuel line).
Turn ignition to ON, without starting motor.
Connect terminals Fp and +B of the check connector (diagnostics box on pass side) and your fuel pump will kick on and start squirting out your fuel line you have disconected. This is how I bled my EFI system after hg job (MUCH thanx to bumpin yota, by the way, for this idea) and it worked great.

Any way the new PCV valve is screwy?

good luck man, and post what it was when u figure it out.

 

I put a new gasket under the valve cover and oiled it. The tech said to use RTV sealant on just the corners of the valve cover, but I'm pretty sure the FSM does NOT specify that RTV should be used.

With a new gasket and the bolts torqued, I don't think it should leak. Is there even vacuum under the valve covers?

 

My next geuss is the EGR valve, it could be sticking open or not fully closing(needs cleaned). It would act like a small vacuum leak. Or, did you make sure the EGR gasket was in good shape when you put the EGR back on the plenum? Are the nuts plenty tight?

Positive Crankcase Ventilation (PCV) requires a small amount of vacuum under the valve covers. Though I agree, shouldn't be leaking without RTV, that's fine.

 

btw, the FSM DOES call for sealant at the corners of the valve cover gasket.

 

Well... when I did a rebuild on my 22re, it was running great, then i warmed it up, adjusted the valves, and put the Vcover back on. I didn't give the sealant enough time to set and when i cranked it, it ran like crap because it caused a vacuum leak.

So yes, a correctly sealed valve cover is important.

 

Gasket sealer, not RTV. Though, used in small amounts RTV will suffice. The replacement of the PCV valve does seem "screwy" to me too. Mine is just a hollow tube, no valve to foul up or need replaced. Just clear the tube and it's good as new. Mine's an 88 3vze and could be different I geuss.

 

Ooooh, bummer... You went through all that trouble. Without the RTV, it'll be leaking oil in no time.

If you could post a few detailed pics of your engine bay, that would be very helpful. If you have something crossed up, someone here will catch it.

 

Oh, and I was wrong. Turns out what the FSM calls "seal packing" is FIPG or what I call RTV. My bad. Will probably leak oil without it, mine eventually did.

 

The gaskets were fine and it went back on tight enough, but the thing looks ancient. It's all rusty. I'm in the process of taking the plenum back off to RTV the corners. Maybe I'll catch my mistake on the way down. BTW, anyone know where I can get a torque wrench that goes all the way down to 48 in-lbs? I CANNOT find one that goes lower than 10 ft-lbs. No one has them.

 

I bought a cheapo (rod indicator, with the dial on the handle) torque wrench at ACE/True Value. They had an in-lb version, but I bought the lft. model, it will read less than 10 lft. It's not likely the most accurate piece of junk, close enough by me.

 

Here are some engine compartment pics.

 

It's kinda hard to tell from the pics, but are any of your passenger side spark plug wires resting on the exhaust manifold, egr, or anything else that gets hot? If one is, it will melt through and arc on that metal, causing a misfire.

 

I found the problem. Took the air chamber back off and found that one of the electrical connections on the injector managed to slip under my radar on the last take-down.

Unfortunately I created another problem somewhere along the way. When started, it immediately dies now at idle. I can keep it going by using throttle, and once it revs higher it gets better. As soon as it drops anywhere near idle it dies. It's also surging a bit. I pulled one of the plugs and found that it's running way rich (smelled like gas and black). I can't figure out what's going on now. All the vacuum lines are hooked back up as far as I can tell.

I spilled more coolant this time than before, so I suppose it's possible that one of the plug wells got wet. It doesn't seem like that's the problem. The gas line on the passenger side of the plenum also looks to be ok. I installed a drilled-through PCV valve while I was under there too.

When I took the plenum off this time, I took it completely off rather than propping it up. To do that I had to take off the throttle body. The gasket came off in one piece without any damage so I left it on. I'm not sure what would make it run rich, but this seems like it will be a fairly easy problem to fix once I figure out what's causing it. Any ideas?

 

Anyone?