Loss of power, torque, dead spot, hesitation whatever you want to call it! (1 Viewer)

[LandoNick]

87 FJ60 no smog pump on it just the idler pulley. had an exhaust leak at the downpipes flange that I thought was a ping. Got the exhaust leak fixed. No more ping or what I thought was a ping. so moved the timing more advanced to 9 degrees, drove then went to 11 degrees. Then my 60 started running hot (unrelated) just happened at the same time. so brought the timing back down to 7 degrees. then noticed I had a hesitation, dead spot, at about 1,500 Rpm in all gears. Then in the taller gear if I press the accelerator it barely goes faster. So timing at 7, lean drop to the best of my ability, set Rpm per timing light.vacuum is like at 16 so not great. fuel half way on the site glass, Idles really smooth. new plugs, newish fuel filter. Hemilex told me to try and do the paper clip test on the secondary so I will try that. the carb was rebuilt by Jim C a while ago. I'm just not sure where to focus my investigation. Fuel, plugs, plug wires, one thing I notices while doing the lean drop. the fuel streams in when the accelerator is pushed at first then more of a spray. I don't feel the dead spot when revving in the driveway. Any help in direction would be a huge help!

 

[OSS]

Is the EGR system still active?
If so, that’s a very likely suspect.
If not, then was the distributor recurved?

 

[micruz60]

What is your elevation above sea level?

 

[LandoNick]

Is the EGR system still active?
If so, that’s a very likely suspect.
If not, then was the distributor recurved?

EGR is still installed not sure if it’s working properly.

Distributor not recurved. Running 92 octane

Paper clip results

 

[LandoNick]

What is your elevation above sea level?

171feet

 

[LandoNick]

Carb clean see if there is crud in there?

Anything alarming about the gas flow in the carb?

 

[micruz60]

171feet

Ah, the vacuum 'should' then be around 20-21" hg. The steady stream of fuel into carb sounds right, but you mention spray- is that at the end of throttle push?
To clarify- you are desmogged, and the air rail is gone / with plugs into head? Check the diaphragm / advancer on side of distributor, it could be leaking, also, did you check the stop pin down inside of the distributor? It is a plastic bushing that disintegrates over time, and may be part of the sluggish response, hence why the distributor is recurved after desmogging.
HTH

 

[LandoNick]

Ah, the vacuum 'should' then be around 20-21" hg. The steady stream of fuel into carb sounds right, but you mention spray- is that at the end of throttle push?
To clarify- you are desmogged, and the air rail is gone / with plugs into head? Check the diaphragm / advancer on side of distributor, it could be leaking, also, did you check the stop pin down inside of the distributor? It is a plastic bushing that disintegrates over time, and may be part of the sluggish response, hence why the distributor is recurved after desmogging.
HTH

So idler for the smog pump installed, gold contraption blocked off to the smog, air cleaner to smog pump blocked off. Air rail still there, cat still there, EGR still there I checked the advancer with the timing light. Sucking on a vac hose and it advance the timing. I did not know and have not checked the pin? Take the distributor cap off then what am I looking for?

 

[OSS]

So maybe the EGR system is still working - or not. Easy to rule it out. Remove the vacuum hose from the top of the EGR valve and plug that hose temporarily. Go for a test ride and see if anything changes.

 

[LandoNick]

So maybe the EGR system is still working - or not. Easy to rule it out. Remove the vacuum hose from the top of the EGR valve and plug that hose temporarily. Go for a test ride and see if anything changes.

Black and brown thing on the holder for the air intake?

 

[fjc-man]

Your centrifugal advance “limiter bushing” probably disintegrated like everybody else’s allowing too much advance and too quickly also. There are posts on Mud about making a replacement. The picture shows where the bushing used to be.

 

[LandoNick]

Your centrifugal advance “limiter bushing” probably disintegrated like everybody else’s allowing too much advance and too quickly also. There are posts on Mud about making a replacement. The picture shows where the bushing used to be.View attachment 3013379

Ok thanks I will take a look!

 

[micruz60]

Ok thanks I will take a look!

That's below the plate separating the innards from the rotor, really a PITA to work on leaning over the fender; I used a aluminum rivet 1/4" outer diameter, with a 1/8" inner diameter, cut it down to 1/4" height. It fit beautifully over the pin.
I also was generous with a coat of paint hand-brushed on the inner and outer vac-advance diaphragm to seal up any leaks there.

 

[LandoNick]

Your centrifugal advance “limiter bushing” probably disintegrated like everybody else’s allowing too much advance and too quickly also. There are posts on Mud about making a replacement. The picture shows where the bushing used to be.View attachment 3013379

I’m not sure if you see what needs to be seen

 

[micruz60]

Refreshing to the original post- "deadspot at 1500 rpm, all gears" seems to me that is the secondary. . . what was the result of paper clip test?

I have a off-board distributor that I have been reconditioning: photos below.
Stop pin in shadow below black electrical grommet.

Plastic cover hangs up on side of air gap pickup-signal generator (phillips screw)

Note new black paint on vac-advance diaphragm. Remove E-clip and sq. plate (2 of these) with phillips screw, lift out plate to access the stop pin.

Plastic cover over air gap pickup-(signal generator) ^^

Note plastic cover removed from air gap pickup (signal generator), use small screwdriver to ease it off the pickup.

Since you are dealing with this on-board, I would suggest a cloth towel wrapped around the exposed distributor, bright lighting and a HEAP of patience, also a tiny magnet to help capture those small screws and the e-clip. Once the two sq. plates are off, the air gap pickup should lift out and still be attached by the wires.

 

[OSS]

Black and brown thing on the holder for the air intake?

Pull the red vac hose from the big EGR valve & plug it. Test drive.

 

[LandoNick]

Pull the red vac hose from the big EGR valve & plug it. Test drive.

View attachment 3013481

I pulled the hose off and drove no difference. I will plug and see if anything changes. I sprayed som carb cleaner in the carb while it was running. That smoothed the idle even more. but the same issue was there. it almost feels like the clutch is slipping if that makes sense, like no power is being delivered. Would the EGR issue not effect the idle? its just under load.

 

[LandoNick]

Pull the red vac hose from the big EGR valve & plug it. Test drive.

View attachment 3013481

capped those two nozzles drove no difference. Should it drive worse or better?

 

[LandoNick]

Tomorrow I will pull plugs, see how they look. They are new but you never know. But I would think it’s wouldn’t idle well if there was an issue.

 

[OSS]

Sounds like your egr system isn’t the cause of the problem.