Rough running after valve job

[FJ4006791]

Hello and Help.

New to the forum.

1976 FJ40 pretty much bone stock, desmogged, new dizzy from trollhole.

I've owned the rig for just over two years. Had the carb rebuilt and replaced distributor. Was running fairly well with an occasional backfire.

Backfiring got bad so I brought it to a local shop I trust. He found that there was no compression in one cylinder. 4 were at 140 and one at 120. Pulled the head said valves were burnt. Had him send out the head. he got it all back together and he cannot seem to get it running properly. It runs very rough, worse than when I left it.

He thinks it is some sort of timing issue. He asked if I knew whether the lifters were solid or hydraulic, he thought they were solid. Are they?

He also asked about the timing chain and the cam shaft. He feels there is something easy that he is missing because he is not familiar with the vehicle.

I'm sure I need to supply more info but this is my starting point.

Thanks

 

[Steamer]

Your engine, if stock is a 2F and has solid lifters. There is no timing chain. It’s gear to gear. (crankshaft gear to camshaft gear)

Welcome to the forum. Show us your rig. Lots of pics is good. There’s a lot of keen eyes here that can tell a lot from good pics.

Good luck!

 

[FJ4006791]

Thanks Steamer,

My mechanic said something about possibly a broken tooth. Is that a likely cause, something they are prone to?

 

[roadstr6]

Not likely. Are plug wires hooked up correctly? Valve lash set properly? When the intake and exhaust manifolds were removed were they checked for flatness? Any vacuum leaks at the manifolds? I hope you used a Toyota head gasket.

 

[Steamer]

Compression numbers after the valve work would be useful also.

 

[SteveH]

He thinks it is some sort of timing issue. He asked if I knew whether the lifters were solid or hydraulic, he thought they were solid. Are they?

He also asked about the timing chain and the cam shaft. He feels there is something easy that he is missing because he is not familiar with the vehicle.

You're asking all the right questions, and you won't find a more knowledgeable bunch out there, than right here on Mud.

But, if your mechanic is asking you about timing chains and hydraulic lifters on a 2F, he may mean well - but you need a new mechanic, well-versed in old Chevy or Ford (or even Toyota) straight 6 engines. The fundamental design of this engine goes back to the 1930s and 40s. Your mechanic should at least have a genuine Toyota factory service manual for the 2F, while working on this engine, and follow it to the letter.

Keep posting updates - we can get you through this.

Steve

 

[65swb45]

Since you are the one with the Internet, do some FAQ searches on how to adjust valves and let him know.

Intake: .008"
Exhaust.014"

TDC 1st rev:123579
2nd rev: 4 6 8 10,11,12

Do it once cold just to get er in the ballpark, then a second time after she's all warmed up.

 

[FJ4006791]

I talked to him this morning. He found the proper procedure in a mitchell guide he had. He called this afternoon and said it's running great. Thanks for the help.

 

[65swb45]

It's amazing what a valve adjustment can do.

True story. I bought a 40 for parts the year after I opened my shop. Customer said it had a seized motor. Sent the pink and the plates to the DMV (I am a licensed dismantler) and took deposits on the top, doors and windshield.

My buddy Marty Weatherwax came by, and we threw a battery in it to test all the electricals. I told him to turn the key to the ON position so I could check turn signals.
He accidentally turned it to START and it turned over, to both our surprise.

I pulled the oil filler cap off and saw the rockers swinging wildly. So pulled the VC and did a valve adjustment. Motor purred. SOB. I called the PO and said WTF?

He'd changed the HG but didn't know the truck had solid lifters.

It was the only time I ever parted out a good rig.