After 2 weeks of driving the cruiser to work (approx. 40m), she starts to complain...

[mr_manny]

problem:
The cruiser appears to load-up and stall at speed.
I experience backfiring out the exhaust and lack of power until Fmotor shuts down.
It appears to only happen on the freeway while in 4th gear.

If I slow down, I am occasionally able to keep her running when backfiring begins.

After each time, I am able to re-start and drive away without a problem...as long as I keep her under 35mph.

I will review plugs/timing, replace fuel filter and inspect fuel tank over the weekend (through sender?).

manny 72fj40

vintage ignition with holley 2brl on 72 Fmotor

 

[toddslater]

If it does it after you put the new fuel filter on, I next check the fuel pump. From there I'd check/renew the condensor, check/renew points along with your timing. Is it still running the ballast resistor ?

 

[JohnL]

WAG here, but are you in 4WD on dry roads?

 

[ken_79-fj40]

If it's still got a points distributor, definately check and make sure your points/condensor/ and ballast resistor are wired properly and working properly. Mine was wired wrong and I drove it daily for a couple weeks, then it started bucking and choking and died. Let it sit for a while, fired right up, drove a few miles, then started puking and coughing again. Towed it the rest of the way home with my trusty toyota pickup. Wound up being wired wrong (I had no ballast resistor) and I fried the condensor. Wired it right, it's been fine ever since.

 

[mr_manny]

FJ runs fine, as long as I stay off the freeway.
Electronic ignition is on the list...still running ballast resistor

If I have low fuel pressure, should I stick w/mechanical or upgrade to electric?
thanks for input,
manny 72fj40

 

[IDave]

Mechanical fuel pumps work fine with aisen carbs. Dunno about holley crappers. But they may need more and more even pressure.

 

[BJ70/85]

A mechanical pump should be fine for a carb. You should have 3-4 p.s.i. on the carb inlet line. Maybe your float level is too low in the carb. Is your air filter clogged?. Check with someone to see what your fuel pump volume should be, then test it. I'd stay away from an electric pump, it may produce too much pressure and force the needle valve off the seat causing it to fload.

 

[BJ70/85]

I'm not sure about Toyota's, they should be the same as other carbs. I usually use a min. of 1/2 a liter in 30 seconds at idle for volume. If you don't have this check for restrictions in your lines

 

[Desertdave]

Wish I knew you were still running a holley, I would have given you mine as a spare, along with the info I collected on how to make it run properly, when you visited with me last weekend. Available if you are needing it.

As said above, wacky ignition issues are possible, once you verify fuel delivery. If it's backfiring, it's putting fuel into the exhaust system where it ignites. Other primary source of backfiring is burned valve, or maybe way out of adjustment valves. Only other physical cause of loss of power after some high RPM driving (that I can think of) is exhaust restriction that gradually kills the engine.

 

[mr_manny]

Wish I knew you were still running a holley, I would have given you mine as a spare, along with the info I collected on how to make it run properly, when you visited with me last weekend. Available if you are needing it.

As said above, wacky ignition issues are possible, once you verify fuel delivery. If it's backfiring, it's putting fuel into the exhaust system where it ignites. Other primary source of backfiring is burned valve, or maybe way out of adjustment valves. Only other physical cause of loss of power after some high RPM driving (that I can think of) is exhaust restriction that gradually kills the engine.

Definitely interested...I hear lots of good things about stock carbs

Hope to have FJ back on the road in time for the bayarea cruiser luchin Nov 20th...
your going right?

manny 72fj40

 

[JohnL]

Are you experiencing drivetrain windup? Are your differentials locked and are you in 4WD on the dry highway? Does it happen when you are in 2wd? Can you recreate it while just idling, not rolling?

 

[mr_manny]

2wd on dry highway...unlocked.
can not recreate while sitting/idling.

I have to remember to check the rear-view if it happens again (look for overly rich condition).
It feels like I ran out of gas, prob. fuel filter or rusty tank

manny 72fj40

 

[Matador98]

A mechanical pump should be fine for a carb. You should have 3-4 p.s.i. on the carb inlet line. Maybe your float level is too low in the carb. Is your air filter clogged?. Check with someone to see what your fuel pump volume should be, then test it. I'd stay away from an electric pump, it may produce too much pressure and force the needle valve off the seat causing it to fload.

Not if you run a regulator. I am running MAF electric conversion kit mounted on the body at the tank, and have a low pressure holley regulator (its a damn big regulator too...I was suprised when I opened the box) with one inlet and two exit, one to go back to the tank. Works great, and after I set it correctly, the gas holds seady in the center of the glass all the time.

 

[nspctr1]

sounds like fuel pump to me. As far as the type, go back to stock, I ran electric in my 75 for a few years but was a pain in the A**

 

[mr_manny]

I replaced Ffilter and inspected Tank, both appeared to be fine...I need to verify that there isn't another filter inline somewhere .
I did find it difficult to verify the ignition timing, as the dot on the flywheel was nowhere to be found w/the adj. timing gun.
I tested for TDC and made a mark on the Fwheel, which resulted in giving me a 15degree ignition timing.
Is it possible to install a flywheel incorrectly on a 1F motor? I'm just wondering how the original TDC indicator could be so far off...
I also tried a replacement coil, but found that the new coil (accell) did NOT trigger the timing light (with or without ballast resistor). I guess it's possible that the aftermarket coil could be designed for electronic ignition?

thanks,
manny 72fj40

 

[DitchCruiser]

Had almost the exact same problem - My Cruiser would run fine for a while, loose power, backfire, and be pretty much out of commission until it cooled down for a while. I checked vacuum lines, fixed an EGR leak, and changed the distributor - no help. I finally decided to rebuild the carb. When I was taking it off I noticed that the four mounting screws were barely hand tight. I got it rebuilt (which I probably didn't need to do) and put it back on and it was almost impossible for me to get the four mounting screws tight. I would bet that many people may have this simple problem - If the mounting screws aren't tight your might suck in air and eventaully screw up the air/fuel mixture and backfire. I'm almost positive this was my problem, it's worth checking in your case.

 

[Jukelemon]

Need to take off that carb and thoroughly clean it. All jets and all passage ways. It sounds like a jet issue i.e. clogging. I have found that if a carb runs fine in a particular speed range but not at others, it is indicative of carb failure corresponding to the stage i.e. idle, intermediate, main. all it takes is just a little build up in the passageway and your screwed.

 

[Jetboy]

WAG Might just be the vacuum advance/retard. Had a v8 that had a bad vacuum advance and it would run fine for a while and once warm it would cut out like fuel problems, but at idle and under no load it would run fine. easy to check too.

 

[johnny]

if i know anything about cruisers, which is very little, i would say its the condenser. i had the exact same problem myself once upon a time

 

[mr_manny]

I replaced both filters with clear units, which made it easier to see that the upper filter was NOT getting enough fuel (level was at very bottom of filter).
I replaced the FP, with ZERO difference. After limping to local parts house, I picked up some fuel hose to by-pass initial filter...wala, upper filter is now full.
I think there must have been crud in line, as I blew into replacement line prior to installation. I haven't replaced initial filter, or have had a chance to clean tank...currently completing a frt/rear disc-brake upgrade

I will also be installing a 2F rocker-cover to make it easier for an HEI install.

Thank you all for your replies, another issue resolved...(new FP doesn't hurt).
manny