My '66 FJ45LV Saga (1 Viewer)

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Mar 9, 2020
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I bought this thing in early March of this year and have made progress on virtually every front, but I still am not comfortable just getting in and driving it more than a couple miles at a time. It just seems lacking power in every respect.

I think I may have finally stumbled upon what’s going on with her.

I know this is a low horsepower engine (advertised at 135, but actually more like 120 hp), and the truck is heavy at 4000 lbs, but it has always felt particularly sluggish. That became super obvious when I drove my son's again last week. His truck is lighter and has 10 more horsepower, but the difference was night and day. My truck will hardly pull the small hill up to my nearby shop. It also backfires occasionally when I try to accelerate quickly pulling into traffic.

I decided to mess around with the timing and carb to see if I could get it sorted out. When I set the timing at the bubble (7 btdc), it would idle and sort of accelerate with no load on it, but put a load on it and it wouldn’t hardly pull itself. To get it to run decent at all, I need the initial timing set at 16-18 degrees. I made sure the advance mechanisms are working and was able to set the points out on my bench to make sure they are dead nuts on. It's driveable, but just doesn't feel free. Also, I can’t detect vacuum at the advance pot.

I broke out my vacuum gauge (and had to fix it, because it has been sitting so long) but at idle, the engine only pulled 2” hg (-1 psi). I have verified that I do NOT have any vacuum leaks, I’ve made sure of that. I have tried two different carburetors and the problem persists. I pulled the intake/exhaust off, and made sure they are flat and co-planar.

Having eliminated everything else, I'm left to conclude the only thing it can be is that the cam is retarded. Turns out that these early f135 engines (at least up to '65) came from the factory with a “silent” fiber cam gear. While I don't know for sure about the '66, I believe mine has been replaced and whoever did it didn’t align the cam and crank correctly. That would go a long way to explaining why I found ALL the front cover bolts loose when I went to change the water pump back in May.

I guess it's time to yank the radiator, pull the balancer and front cover and see what I have.

Cheap fix, but gonna take a few hours.

Any other ideas, gents?
 
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Pighead

Stop calling it an FJ
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What happens when you advance your timing more?
I just use my vacuum gauge to adjust timing. My BB (bubble) is so far behind the bellhousing window that I have no idea what degrees I'm at. I just advance until I get the best vacuum then back off a degree or two. Back off more if it pings...
I'm using manifold vacuum, not carb vacuum.
 
Joined
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Messages
116
Location
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What happens when you advance your timing more?
I just use my vacuum gauge to adjust timing. My BB (bubble) is so far behind the bellhousing window that I have no idea what degrees I'm at. I just advance until I get the best vacuum then back off a degree or two. Back off more if it pings...
I'm using manifold vacuum, not carb vacuum.

I'm tapped into full manifold vacuum. The gauge works fine. It sits solid at 2" Hg. (Where the gauge says "late cam timing" behind it, incidentally. ;) )
 
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Are your valves properly adjusted.
I was reading 8" on mine, and could not find a leak. I was told to adjust my valves. They where very close. After adjusting them, I had 16" or so.
 
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Are your valves properly adjusted.
I was reading 8" on mine, and could not find a leak. I was told to adjust my valves. They where very close. After adjusting them, I had 16" or so.

That's a good point. Thank you. I checked them when I first got it running (it had been sitting since '05) and they were good. I haven't checked them since April, but I will. I did do a compression check and found that all cyls. were within 3 psi of 125, except #3 which was at 115.
 

Pighead

Stop calling it an FJ
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I'm tapped into full manifold vacuum.
Good. After you adjust your valves (with engine warm), try advancing your timing more while watching the vacuum gauge.
Also, you will not get vacuum at the carb port at idle, only when the throttle opens
 

Pighead

Stop calling it an FJ
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Also, I can’t detect vacuum at the advance pot.
Yeah, I’m measuring at a port on the manifold.
yes, I saw you mentioned that you were measuring vacuum from the intake manifold, good.
I also saw you mention no vacuum at the advance port, just thought I'd tell you why.
My main question is; does your manifold vacuum increase if you advance the distributor timing from the 16-18 degrees you have it at now?
Your vacuum gauge may not know the difference between late cam timing and late distributor timing and trying a little more distributor advance is easier than pulling the front cover...
 
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yes, I saw you mentioned that you were measuring vacuum from the intake manifold, good.
I also saw you mention no vacuum at the advance port, just thought I'd tell you why.
My main question is; does your manifold vacuum increase if you advance the distributor timing from the 16-18 degrees you have it at now?
Your vacuum gauge may not know the difference between late cam timing and late distributor timing and trying a little more distributor advance is easier than pulling the front cover...

Yeah, it doesn't move. Again, the gauge works fine though.
 
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Thanks guys. I realized in the middle of the night that I have done all of the things suggested, but at different times throughout the process. I removed the intake/exhaust and had them milled. I have two different carburetors (both rebuilt) and it still does it. I have removed and plugged the vacuum ports. I have sprayed brake cleaner around the ports and verified no leaks.

I need to go back and recheck each of these things more methodically before going after the timing gear. I'll figure it out, I always do, it's just maddening until I get there.

Oh, if any one with an older FJ 1bbl manifold cares and is interested... Holley makes a sniper kit to fit. It's actually a kit for the Mustang, but the carb base is the same. The kit without the lines, pump and filters is only $749. Once I get my base issue sorted out, I'm going that direction.

Check it out, here: Holley Sniper EFI 550-552 Holley Sniper EFI Autolite 1100 - Gold
 
Joined
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Messages
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I realize I never updated this thread... My issue was as basic as I thought I would find. It turned out to be a very slightly loose/slightly corroded wire at the ignition post on the ignition switch. It would drop voltage to the positive side of the coil, intermittently. I found it by hooking up a volt meter to the coil and watching it drop to 3-5V at the same time it started running s***ty. I verified it by jumping around it directly from the battery +. Fixed that and my gremlins disappeared.
 
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