(2f) Pistons 5 and 6 are not fireing???

[Droopynut]

Once agian I require the input of the experts.

I brought my FJ60 to a local mechanic and he said pistons 5 & 6 were not fireing.

He is completely baffled by this. He says that compression is great with all pistons and it's not an ignition or timing problem. He said that he needs some time to get in there and find the problem.

Any ideas?

This motor only has 120k so what is going on here?

DAN

 

[Mr. Toad]

Once agian I require the input of the experts.

I brought my FJ60 to a local mechanic and he said pistons 5 & 6 were not fireing.

Any ideas?

Plug-up the manifold vacuum port that feeds the booster and see if they still aren't firing.

For that matter, make sure that the PCV and brake booster vacuum lines are not connected in each others' places. (Don't ask. D'oh! )

 

[lunyou]

always start simple, make sure the spark plugs are in the block......make sure the plug wire is plugged in..

lunyou

 

[Mace]

so he has compression and spark on both cylinders?
But no ignition??


Sounds fishy..
Even with a huge vac leak, they should fire a bit..

 

[Droopynut]

yeah...

it's got plugs

I can't beleive a vacuum leak would cause pistons to not fire, but I'll tell him to check it out.

This 2f motor is very unique.

 

[miletwo]

plug wires would be my next guess

 

[candograge]

may be silly do you think the ignitor under a load is dropping those cylnder ? If so i have one that is good i will send you nc .

 

[candograge]

on second though if you have spark at the plug timing is right and compression you need fuel to make it work ,i thing you should check intake vales and rest of valve train .

 

[Mr. Toad]

I can't beleive a vacuum leak would cause pistons to not fire

Believe. Once warmed up (with a mis-routed PCV/brake booster pair), the failure to ignite in # 5 and 6 is accompanied by intermittent popping in the exhaust system when the unburned air-fuel mixture -- which was too lean to ignite when the spark hit it in the chamber -- detonates on the way to the tailpipe. And the exhaust stinks to holy hell too.

Good luck tracking it down. And post-up when you figure out what the cause is.

 

[Droopynut]

although I'm not a real mechanic, I understand the very basics of the internal combustion engine...When he told me that those pistons aren't fireing, I narrowed it down to something wrong with the valves,cam or something related to the intake valves...the PCV vacuum hose theory makes sense since it's located right by #6 piston...I'll check to see if the PCV and booster hoses are swapped.

Maybe the #5 and 6 chambers are gunked with carbon not allowing combustion...

I'm starting to learn that with the 2F, anything could be wrong.

 

[Mr. Toad]

I'm starting to learn that with the 2F, anything could be wrong.

Amen to that, bro.

 

[Mr. Toad]

So you've had two years to fix it. What was wrong with it?

 

[Droopynut]

The pistons were fine...it turned out I just needed a new intake cuz the old one was warped letting exhaust gases into the chamber. The mechanics really had no clue what they were dealing with.

Wow...this was an old post

The truck has been running great for the past 2 years...but rust is starting to take over. It just needs new fuel lines and the piece that goes into the tank (inlet/outlet) what ever it's called.

I figure with new lines... it will run even better (without pieces of rusty meal flowing into the carb