Engine hesitation (1 Viewer)

[Groucho263]

Fellas...here is the update. The range of motion for the rotor went from about 3 degrees to about 20 degrees after cleaning it up and removing the 2 small lock washers that were randomly sitting in the bottom of the dizzy. Look at the picture...with it at 7btdc, the rotor is pointing at about the #2 spark plug which is not right. I pulled the dizzy and reset it to be pointing at the #4 spark plug (2nd picture). Engine starts and idles pretty nice (good oil pressure)...any added throttle makes it sputter/stammer. I have my old carb (that I rebuilt...but replaced with the City Racer carb because I couldn't get the engine to start (a long while back). I'm going to put that original carb back on to see if that makes a difference and will update.
*Note...for others with the same issues...the reason for the backfire was because I had the rotor 180 out from where it needed to be.
**Note 2...I have not installed the new fuel pump yet...trying to do one thing at a time.

 

[Dizzy]

On a 4-stroke engine, right. Regarding the motion of the pistons, From the beginning, exhaust stroke (exhaust valve open), then intake stroke (intake valve open with fuel charge entering). That is 180 distributor and camshaft degrees, so far. Then both of the valves are closed for the, compression stroke, and, at the spark timing, ignition. After that, the power stroke. Then it begins again.

Imagine that ignition happened sometime during the intake stroke. You would have a condition where there is quite a bit of pressure in the cylinder chamber where the camshaft lifter, pushrod, and rocker assembly has to work against a highly resistant intake valve. Also, all of a sudden becomes great positive pressure in the intake manifold and everything attached to it, where normally it is somewhat negatively pressured. I really wonder how the intake valves and pushrods can handle it without becoming distorted.

I opened one head that I bought, and I found a bent valve (exhaust), and I can't help but wonder if it simply missed ignition during the compression stroke, but burned during the exhaust stroke? Or did it just get abused by other means. Either way, I had to cut off the valve stem because it wouldn't fit thru the valve guide. It turned out that the valve guide was cracked at the top as well.

I'm no expert, but I'd check the valve lash after a big backfire, in theory. And record any necessary adjustments. Then I'd look at the spark plugs for any changes in gap.

However, the distributor rotor is notched. It only goes on one way, so if the cap was assembled correctly regarding the housing, then, I'm confused how you report the 180 degrees off problem.

 

[Groucho263]

I'm no expert, but I'd check the valve lash after a big backfire, in theory. And record any necessary adjustments. Then I'd look at the spark plugs for any changes in gap.

However, the distributor rotor is notched. It only goes on one way, so if the cap was assembled correctly regarding the housing, then, I'm confused how you report the 180 degrees off problem.

Ok...I'll check the spark plug gaps and pull the valve cover and check the adjustment. It wasn't a huge backfire, more of a pop, but caught me off guard. I think I was not on TDC...I was 180 out from that? Either way, when I changed it, it started and ran, etc.

 

[Groucho263]

Update...got the original carb on there and adjusted the timing and got the motor to start. Runs well at idle and stutters again anytime any throttle is added. 2 carbs and similar performance. Timing seems good and the rotor points to the #4 plug. Waiting on parts for EGR removal and will install that and adjust the valves after the install and see how it goes.
Quick question...for the coolant flush...I take out the drain plug for the radiator and the engine block then remove the lower hose. Do I run the hose into the radiator with the engine started and lower hose removed so the water flushes out the hose/engine block plug?

 

[Groucho263]

Update...took the valve cover off to try to do the valve adjustment and the inside of the valve cover didn't look good. Tried to start it for a couple tries and it didn't start. Had the same froth in the valve area. Attempted to take the radiator cap off to see if there was oil in the water and the pressure blew coolant out (the engine was completely cold...didn't get it started. I never did get the coolant flush done before this. I assume that's a head gasket? Assume also the head gasket could be the reason for my problems? Not what I wanted to find out.

 

[Dizzy]

Sorry for the emulsified oil.

What does the radiator cap, and under it, look like?

 

[Groucho263]

Under the radiator cap kind of looked normal, but when I tried to open it (totally cold), there was a pretty good amount of pressure pushing coolant out. Now, I'm assuming there isn't very much coolant in the system and I was going to drain it to do the flush.
Trying to start the engine, towards the last try, it seemed the starter struggled. Then I did the radiator cap and the pressure released.

 

[Dizzy]

Let's just hope that it is something simple, like a head gasket.

 

[Orange76Cruiser]

Can’t help on the engine hesitation, as it’s a problem that I have as well, but I may be able to help with the turn signals not working but the flashers do. I am going to give you 2 answers but since the flashers work I think that it will be answer #2.

Answer 1 is make sure all of the turn signals are well grounded. The lights ground by contact with the body so if there is a lot of corrosion you could be getting a partial but not a full ground.

Answer 2 is check the wattage on the turn indicator bulbs. They need to be 20 -25 watt . Sylvania 1159 are 20.5 watt. Check all the lights, front and back.

Either way you usually get the lights to turn on but not blink.

A third possibility is a burnt bulb but that would only affect one side. The side without the burnt bulb would work but the side with the burnt bulb wouldn’t.

If both sides have a burnt bulb the hazards wouldn’t work.

What is happening is the same for any of these conditions. The flasher needs a minimum current draw to work. With a bad ground you don’t draw enough amperage. With low bulb wattage you are doing the same. Putting the hazards on means ALL of the bulbs are lit, and together they draw enough current to make the mechanical flasher work. The flasher works by the current heating up a bi-metallic strip inside the flasher that snaps open contacts for the lights which stops the current so the strip cools and the contacts close again. The question is whether you have a ground, burnt bulb or a wattage problem.

 

[Groucho263]

Hey @Orange76Cruiser ...thanks for the message. Here is what I did to get the turn signals to work. I got a rear wiring harness from @Coolerman that helped fix a lot of the rear brake light issues. Turn signals still didn't work (they came on steady for the most part, but didn't flash)...so I removed the hazard lights switch and cleaned that. I added a ground wire to the front turn signals assemblies (the rear wiring harness from Coolerman came with the grounds) and grounded them on the fender in the vicinity of where the bullet wire connectors were. Then, @Cromagnon spent a lot of time with me to make sure all the grounds were clean. There was only one more thing it could be since the bulbs were brand new (and the correct bulbs), they were getting roughly 11.8 volts...we tried this flasher: Amazon product ASIN B0786CX8LP and it worked. I had to run a ground to the steering column brace, but they work great.

I spent a ton of time getting the electrical to work (I haven't attempted the reverse lights yet...but think that should be a quick fix) and have everything working like it's supposed to at this point. I even had to replace the speedo cable (see pic) and run it straight to the speedo instead of to the emission box thing (the technical term).

For the hesitation...I have tried 2 different carbs, installed electronic ignition/new coil, removed inline electric fuel pump, new PCV, re-stabbed the dizzy (it was way off). I have a new OEM fuel pump that I haven't installed yet...and EGR block off plate that is not installed yet...but will do the EGR when I re-install the head.

Now...I have to remove the head gasket (and have a shop machine that and do the valves) to see if I can get it to run. I think that head gasket has been my main problem...but I have really not wanted to pull the head. Hopefully, it's like doing the valve adjustment (seems intimidating, but not too bad when you actually do it).
I'll keep updating as I do the work...really just want to drive it.

 

[Groucho263]

Pulled the head today. Pictures attached. The Heater Union Swivel broke due to major rust...and a couple other screws/bolts broke due to major rust. Taking the head to a machine shop tomorrow to machine the head and do the valves. Will have to fish out those broken bolts while waiting on the head. Btw...I had to get a big fricken screwdriver to pry the head off...and had to remove the alternator (forgot that part at first).

 

[Groucho263]

Got the head back from the machine shop. Nobody mentions how bad it sucks to scrape off the old head gasket. While waiting for that to come back, I cleaned up some parts getting it ready to reassemble. I decided to paint the block black and took the push rod cover off to clean it up. Holy crap...talk about a ton of gunk.

 

[Groucho263]

Pretty sure it isn't supposed to look like this:

 

[Cromagnon]

In for a penny, in for a pound... or two of sludge!!! The rabbit hole is getting deeper and the light at the end of the tunnel...is a .

 

[Groucho263]

@Cromagnon ...everything you just said is so true. Luckily, this was the first Fj40 I decided to get...and now am no longer wondering why it sat in a field for 20 years.

 

[FJ40Jim]

Replace the Vatozone PCV valve with a genuine Toyota billet steel PCV valve & a new grommet.
It does matter.

 

[Groucho263]

@FJ40Jim, roger that. It's on the way. I still need to weld small plate to the EGR valve plate. Question...do I cut off the pipe from the inside and outside of the plate and weld the new plate on the inside? The inside pipe goes into the intake manifold. I'm assuming I can cut that off flush and weld the plate to the inside?

So much sludge...still need to clean the area where the pcv valve is...and the remainder of the cork from the push rod cover.

 

[Cromagnon]

That looks gooooooooooooood!!!!!!!!!!!!!

 

[Groucho263]

That looks gooooooooooooood!!!!!!!!!!!!!

That was a pain in the ass.

 

[FJ40Jim]

EGR removal