3fe help (1 Viewer)

[Smplybttr]

My head gasket blew and I finally put it all back together, with the help of some club members. She has a miss, though and I can't figure out why. If I put a piece of cardboard in front of the tailpipe, it intermittently POPS back against the pipe.

The plugs and wires are new, the head was decked and tested, the valves have been adjusted twice. The timing has NOT been checked, so I don't know if that would cause it. My compression numbers are good, except #4 and #5 are 120 and 135 respectively instead of the 149ish. The truck has 175k miles on it.

Any thoughts?

 

[GLTHFJ60]

Injector wiring for #2 injector was repaired. Did we verify that this cylinder is now firing again?

This is a seriously frustrating issue. Not sure what could cause this miss.

 

[Smplybttr]

I'm headed out in a few to go back over plugs and vac lines. Someone else suggested that I recheck the torque on exhaust manifold, too. It's a good thing that I already drink or this would definitely push me to it...

 

[Smplybttr]

I posted this on the 3fe Yahoo group:

I am at a complete loss. I used a vac(cine) gauge and it holds perfectly steady at 18". Drops and elevates and then holds when revved. I was wrong on the compression #s. They are 140, 155, 140, 130, 135 & 140 both wet and dry. If the valve adjustment was incorrect, would it hold steady on the gauge? Would incorrect timing allow for it to hold and still miss?

Pulled the plugs again and they are properly gapped and look uniform. #2 may be a little hot, but doesn't seem to be far from norm. (see pic).

Idle is right at 650 rpms. No CEL codes. I disconnected the battery for a day and it sounded better for about five minutes and then right back to it. Hot or cold, it doesn't make a difference.

Here are a couple of videos that show the 'pop' and the miss:

http://www.youtube.com/watch?v=ss84z0pzBwU&feature=plcp

http://www.youtube.com/watch?v=gqwDD2jQLJo&feature=context-cha

http://www.youtube.com/watch?v=gqwDD2jQLJo

I don't want to do it, but I'm about to break down and take it to a shop. If I did so, would they have a magic machine that would tell me exactly what the issue is or would they fumble around like I am?


Thanks,
Terry

 

[Smplybttr]

I was asked to pull the small vac hoses off of the air cleaner to see if there was an idle change and this is my response:

There is no change when I pull either of the small hoses and now that I put the plugs back in, it is stumbling a little bit at idle. Would incorrect valve adjustment cause this?

Here are two more videos:

http://www.youtube.com/watch?v=bFPVHArxE5U&feature=plcp I'm hoping that the exhaust smoke is just condensation is from the water that was in the oil from the blown HG. I changed the oil, but did not change the filter yet. My plan was to run it for a couple hundred hours and then do a full change.

http://www.youtube.com/watch?v=OcZB496yxNY&feature=plcp You can hear the stumbling on this one.

Terry

 

[alex4640]

I'm no expert mechanic so take this advise for what it's worth. . . $0.

I suspect one of two things. Either you have a vacuum leak. Spray a carb cleaner on all the vacuum lines and any other possible inlet of stray air. If the idle goes up while you are spraying an area you have an air leak there.

Second possibility is a bad fuel injector. May have been fouled when you blew the HG by the EGR system pulling water back into the intake.

 

[Smplybttr]

Thanks Alex,

I've put a vac gauge on it with no loss of vacuum and have tried the spray method for other areas that wouldn't show and I sent my injectors off and had them cleaned and balanced. Both are good ideas, but unfortunately already marked off of my list of issues.

Terry

 

[4thwheel]

i had the same problem after a complete engine rebuild.
1st, did yours run like this before the HG failure? if not...

By all means check all the vacuum port and hose routing per FSM diagram... then recheck them again tracing one line to one pipe at a time.
I had one hose connected to the wrong port (meaning two incorrect connections) and it ran like yours.
after thinking it was a faulty egr valve, replacing two sensors, new plug wires, resetting timimg a few times... I traced down each hose to port connection, corrected one connection (2lines) and "poof" the problem was gone!
purrrrrss now...
good luck

 

[Sev65]

Have you tried pulling plug wires one at a time to isolate the misfire?

 

[lt1fire]

Terry is your 62 desmogged??? Sometimes a faulty EGR can cause a miss

 

[GLTHFJ60]

Terry is your 62 desmogged??? Sometimes a faulty EGR can cause a miss

OOOOOOOOOOOOOOOHHHHHHHHHH. No it's not desmogged. Good idea!

Terry, you should be able to disable the EGR by plugging the vacuum line that's connected to the top of the EGR valve.

 

[GLTHFJ60]

Have you tried pulling plug wires one at a time to isolate the misfire?

Also a good idea. It runs even worse when you remove any of the plugs.

 

[Smplybttr]

As Johnny said, it is not de-smogged. Before I blew the HG I did get a EGR code, but it went away and there are no codes right now.

Unfortunately, I'm out of town for a few days, so I'll have to check it out.

When I drove it, yesterday, I noticed that the valves were chattering a little when I was on an incline, so while there may be other issues, I'm going to have to readdress that.

 

[lt1fire]

If it ever threw the code it could still be messing up..... Mine is desmogged with the BB method but it can still mess around with it. Mine does..... I just haven't gotten around to doing the full desmog.... real easy... you can use expanding plugs... cheapest. Or have a shop make a block off plate from the gasket and do it that way. It makes the 3FE run better so it's worth it even if it isn't the problem. But i'm banking on it since it did throw a code t one point. 3FE's are bad at actually throwing codes when things are actually messing up.