1985 FJ-60 hesitation....stumped (1 Viewer)

[john q]

I bought my 1985 FJ-60 almost a year ago. I have had the 2F engine completely rebuilt to include new manifolds and a new OEM carb. I also had the recalled gas tank fixed @ the toyota dealership. Here is my problem, the guys that did my work are stumped, Every thing works great except that when she is about 45 - 55 mph, she begins to hesitate ( feels like fuel cutting out). I haven't had time to tinker with it, as I keep leaving it with them to research but I think they are at there wits end. Any ideas

 

[GLTHFJ60]

Did you replace the fuel filter when you installed the new carb? I would try to replace that, and if that doesn't work, then make sure that they installed the carb correctly. Then move to the fuel pump.

 

[dd113]

Try and plug the EGR ports on the vac modulator. The EGR valve might be "bumping"open/closed and causing the hesitation.

 

[john q]

The fuel filter was replaced with the engine rebuild. Thanks, I'll try the EGI valve and see where we're at.

 

[Texx]

Advance the timing to the highest idle, (turn distributor counterclockwise)go drive the vehicle under load, retard (clockwise) until you don't hear pinging. This is often the problem with 60's...don't really know why, or care, about the technical details, just know it works well for 60's and 62's. Don't leave the dist. advanced so far that the engine continues to ping under load, or you can do permanent damage.

 

[zebrabeefj40]

Were ALL the rubber vacuum hoses replaced after the motor was rebuilt? If they were not the that would be my first step. New hoses often clear up odd performance problems like you mention.

HTH,
Nick Jennings

 

[john q]

Well, I had to leave the truck with the guy who rebuilt the engine as I am traveling. He is going to replace the EGR valve and see where we are at. I also read about a lot of other LC heads having exhaust stink. After the engine was rebuilt the exhast fumes are TOXIC. This leads me to believe the cat is shot too. I'll keep posting the results. Thanks, John.

 

[flowman]

John q,

Keep us posted-I'm fighting the same thing. Mine was imprroved by adjusting timing (just set back to 8deg BTDC, didn't try Texx's trick..yet). I've replaced all vac hoses, bad PCV, bad VSV and the top BVSV. Will test EGR tonight.

 

[Fearnofish!]

Two things come to mind:
1. When mine had the same symptoms I ended up replacing the dizzy with an HEI from DUI. SOlved the problem. That doesn't explain how it solved it, but it did. My Dist was a mess inside and after putting money in other areas I thought what the heck.

2. Carb leak or float sticking. Both would cause hesitation. If vac leak at the carb then at higher draw the leak could be relevant. Maybe put it in 4 low and increase the revs to those seen at 55mph. Same syptoms? Put some vac grease around the base of the carb and try it again.

Also I have seen floats that are"new" stick and basically lean out the carb at higher draws.

Good luck.

 

[Russ in California]

When I hit 45 in my 85 FJ it seems to not just hesitate but it's like the bottom drops out and you have to almost punch it past that point. After 45mph it's ok.
I talked to Mudrak a while back and he thought it could be the secondary diaphram. Haven't changed mine yet but I'm hopefull.

 

[john q]

Well, fixed the hesitation with an electic fuel pump. I put it in right after the tank so I'll have good pressure all the way up the line. It hasn't hesitated since, but I will put 400 miles on her tomorrow....a little nervous. I'll post how it goes. John.

 

[flowman]

Glad to hear the fuel pump helped--in my case advancing the timing a couple of degrees (BB on the bottem edge of the window) and replacing the PCV made mine run like a champ again! My EGR vac modulator is bad, but she's running much smoother now.

Good luck w/ the trip

 

[lowtideride]

im sure you will be fine...my pump was doing the same thing when it was on its way out...except it was 12am and i was on the was to flca meet....i had a spare but the dudes at the parts shop gave me the wrong one....

 

[john q]

Sweet!!! 450 miles and no hesitation. I replaced the EGR valve and the egr vsv prior to installing the electric fuel pump with no luck, so it was fuel pressure all along. It still concerns me, I had to put the electic pump on, it should work without it. I am going to pull the mech pump this weekend and check all the lines one more time, but the hesitation is gone so I know it was fuel pressure!!!!

 

[john q]

As I was running back through the lines I noticed the PO had taken out the metal fuel line from the mech fuel pump to the carb and installed a standard 5/16 fuel line right over the top of the valve cover. Besides a massive fire hazard this may have had to do with the lack of fuel pressure getting to the card. I am going replace it and then bypass the electic pump and see whAT HAPPENS.