Help! Fj62 hesitation is gonna be the death of me.

Joined
Dec 19, 2015
Messages
18
Location
Daly City, CA
89 62, 260k miles, stock everything, all smog equipment still there (yay, Cali) head was pulled 15k miles ago and completely redone. Everything else checked out ok so I stopped with just the head. Ran great after the work.

Started to get a random hesitation. Which got progressively worse, to the point that she has been parked for a bit. I’ve been through most of it, found lots of issues that needed to be corrected... but none have been the issue.

So far,
Plugs, wires, cap, coil and distributer (cap was not vented, guts didn’t look good. Swapped with known good dist, vented as per the fsm... timing is on point)
Egr tested and functional.
Fuel pump, filter, regulator and pulsation dampener are brand new. Lines are clear, didn’t check actual pressure but failing to reconnect the return told me it’s definitely working!
All vacuum lines have been checked, and/or replaced.
Cats seem ok via the tap on it and listen for loose material test.
Tps is also brand new and correctly adjusted
Tb is clean
Intake hose has seen better days, but isn’t drawing in air.
I know I’m missing some stuff, but here is the kicker. Runs great cold, drive around for 5 minutes and out of the blue just runs like crap. Sounds like it running on 3 cylinders. No power, shaking like a tweaker.
Pulling a code 51, which led me to replace the tps again. Code won’t go away. What bothers me, is when I pull the code... I get 5 flashes, pause, 1 flash, pause. Then it just flashes fast continuously. Doesn’t repeat the code.

Any ideas? Pulling out what little hair I have left on this one. And of course it’s due for smog test in a couple weeks.
 

SteveH

 
Joined
Jan 17, 2005
Messages
4,393
Location
Southern Colorado
Buy a neon tester for the spark plugs, and when it's running crappy, check all the plug wires (ideally in a darkened garage) and see if you're getting a consistent spark to all 6. You need to find out if this is ignition or fuel and which cylinders are not firing (if this is the case).

If it runs strong when cold, you can rule out stuff like clogged cats or a massively leaking air intake hose.
 
Joined
May 3, 2019
Messages
6
Location
Houston
I ran into this issue and it turned out to be several things for me. Definitely check the fuel pressure at the CSI and again at the fuel filter to make sure it is in spec to the FSM - it will run with crappy fuel pressure but get no power when you step on the gas (I realize you replaced the fuel pump but weird things can happen).

Also, put an actual gauge on the manifold vacuum and watch the needle to make sure it is in spec and not bouncing around all over the place. Do this when the engine is running cold and again when it starts acting up.

Recheck timing as well to make absolutely sure you have it matched to proper 7 degrees TDC mark and not TDC.

I went crazy chasing this down and it turned out to be a little bit of all of the above ...
 
Joined
Nov 2, 2015
Messages
142
Location
Memphis
Check for vacuum leaks with starting fluid

GIve 'er the ol water bottle with a hole in the cap steam test on the manifold, see if you can isolate which cylinder(s) it is. I'm almost thinking you have a fuel injector/injector wiring harness problem but that usually won't give you a CEL.

You can also do a stethoscope to the fuel injectors test and see if one or more sound different than the rest. Good ones sound snappy, bad ones sound dull and grindy.
 
Joined
Dec 19, 2015
Messages
18
Location
Daly City, CA
Ok. So I made some progress.
Tested spark, all good.
Timing on point.
Stethoscope’d the injectors. All giving a clean clackity clackity (technical term)
Vacuum holds at 18-18.5. No fluctuations. But when it runs like s*** it drops to 17

Just a thought, I noticed it runs like s*** when the idle finally drops to 650. Which takes a while.

Another wrench in the gears, I disconnected the battery for a couple days (only cause I got busy) code 51 is gone. Now I have code 11. Before I test every damn lead on the ecu. Any ideas?

Oh, where in the world is the efi fuse? Is it called something else or am I crazy?
 
Joined
Jan 13, 2011
Messages
526
Location
Corrales, NM
EFI fuse should be in the fuse box on the drivers side about knee high. Theres a cover you pull off. Should be a diagram on the back of the cover that will show you where the fuse is located.
 
Joined
Dec 19, 2015
Messages
18
Location
Daly City, CA
EFI fuse should be in the fuse box on the drivers side about knee high. Theres a cover you pull off. Should be a diagram on the back of the cover that will show you where the fuse is located.
I’m gonna assume it’s the fuse labeled “engine”? Nothing says efi. Yet everyone calls it the efi fuse.
 
Joined
May 3, 2019
Messages
6
Location
Houston
I would seriously consider checking the fuel pressure at the filter and the cold start injector with a gauge. It should be around 35psi to 40psi if i remember correctly. At least you can rule out delivery to the rail as an issue. You can still get pressure and then fuel out if the return line but it may not be sufficient. You can “borrow” the gauge and fittings from AutoZone or another place.

Do you still have the old pressure regulator? Maybe swap it out to make sure it isn't your replacement.

Is the vacuum line to the regulator hooked up?

I want you to solve this because I know the frustration personally.
 
Joined
May 3, 2019
Messages
6
Location
Houston
One other thought ... did you set the timing with the TE1 and E1 terminals shorted on the diagnostic port? And what is your idle when the engine is cold and the A/C is off? How long does it take for the idle to drop to 650rpm?
 
Joined
Dec 19, 2015
Messages
18
Location
Daly City, CA
Yup. Timed correctly with te1 and e1 shorted.

Takes a good while for the rpm to drop to 650. Cold runs a little over 1k. Won’t drop below 900 just idling, need to drive it.

One thing I noticed last night, there is no cold start time switch. But that means there never has been in the 5 years I’ve owned it. 50k miles and never been touched by anyone but me. So it’s not recently missing.

All parts I’ve replaced were one by one trying to chase down this problem. Nothing has changed it. Runs better cold though!

The thing that bugs me, is it’s running great cold. All gears, up to 50 is all I’ve taken it since this issue.

When this started, it started slow. I’d randomly (once a week maybe, daily driving) get a stutter off the line that would clear up by the next light. Month or so later, it’d be once a day. Couple days later I barely made it home.

Fuel pressure test is next on my list. But I have my doubts! Also will be checking all the grounds.
 
Joined
May 3, 2019
Messages
6
Location
Houston
Hopefully you got this figured out!!!! Let us know because it helps everyone else who runs into problems ....
 
Joined
Dec 19, 2015
Messages
18
Location
Daly City, CA
Could it be a dirty air flow meter? Maybe it's getting stuck and telling the ecu that there's not very much air coming in?
ding ding ding ding.

If only I could swear here. This post would have more content.

ok, I’m not 100% sure what the problem actually was, but it was intake related. A previously taped intake hose, could have failed. Though it passed carb clean and propane tests. So maybe not. I re- taped it first stuff and giggles.

Now the afm. Before tonight, all I did was test the electrical side of it. Tonight I pulled it off the cleaner lid. Sure as stuff, it was a bit nasty. I did have a valve job done and cleaned the tb, but not the afm. $12 can of contact cleaner later...

I’ve only driven it for an hour, up to 40 mph. But the problem would rear it’s head long before that. Further testing and tires are needed (screw in the shoulder of one, all are cracking) but I think I frigging got it.

Lesson here, keep it simple stupid. But I am much more knowledgeable on the 3FE now. And most everything but the bottom end is new. I should have dropped an LS in it on day one. Now I can’t cause it won’t just die. 🤷🏻‍♂️
 
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