sam333

If it is flooding I would check you cold start injector and timer( which was allready mentioned) and your fuel pressure and fuel pressure regulator. After you try to start it and you pull a plug/ plugs are the wet and smell like raw fuel?What makes you think it is flooding?

cjsgarage

it does smell like fuel. plugs are wet but not so wet it won't fire. but obviously not turning over. I know cold start injector is spraying, but how can I tell if it's spraying too much? how can i check the fuel pressure regulator if I don't get vacuum? (it won't run). I mean, I suppose I could use a vacuum pump, but isn't the schrader valve under the intake?

sam333

Hook up your fuel pressure gauged and jumper it so your pump runs manually( look up the pressure specs).The manuals with test procedures are on this site. Crank it over a few times to get some fuel from your cold start injector and then unplug it( in case its stuck on). Then try starting it. Sorry got to go to bed, the wife is mad!

davesluggo

I think I have a problem also with my fuel pressure regulator, when I take the vaccumn hose off gas comes out? is this normal?

joknrok

Definitely not normal. As long as you're sure it's the vacuum hose your speaking of, and not the larger fuel return line, you should not get gas. It would indicate a torn diaphragm if I'm not mistaken. The FSM is posted online to show test procedures for the FPR.

joknrok

Did you try jumping the fuel pump in the diag port then starting it? Then at lesat you know you're pumping while sparking.
Didn't work for me though. I discovered my timing is off by 30-40degrees past 0. Bur the distributor rotor points straight at 1 at TDC. whish I could figure ou what's driving the dizzy... cams, or crank. If it's crank driven, I think I'd know for sure its timing belt slip on the cams, unlsss a faulty distrib could throw timing off that much...
I'd love to hear of someone pinning down the solution for this apparant voodool

Paulskey

Have you had any luck? I'm having the same problems with my 3.0L

Team420

I have only seen it suggested here once so far, with no posted results, so... Have you done a compression test? It was mentioned before, the engine needs 3 things to run, fuel, spark, and COMPRESSION( its 4 really, but unless your tb is plugged, you will get air), You know your getting fuel, and you said you are getting spark, and the timing is dead on... this leaves compression..... Check it out... you may be surprised...

My bud got a 93 runner with the 3vze, bought it cheap cuz it had a cold start issue. When it showed up... the p.o. had been messing with the timing thinking it had jumped or something, and he had the thing apart, pieces in the back seat, so I spent a while putting it back together, just to get back to figuring out the cold start issue, which was EXACTLY the same symptoms you describe.... Smell of fuel, tries to start at first, then just floods out... I could get this one going by having a bud stand at the rear pass side door, and disconnect the wire harness from fuel pump while I cranked, after doing this for a few sec, she would fire up, but run really rough till it warmed up a bit, then she ran great!
Well, I spent quite a bit of time over a few month period testing/swapping parts, and testing the wiring, messing with timing...etc Finally I got the bright idea to check the compression and wouldnt ya know... 2 of the 6 cyl had 130 psi( too low) and the rest had 0-25 psi. I assume this was blow by at the rings, being as once it cranked over enough, it would build compression, and start, also...once warm, she ran...and ran pretty well, and started fine, till she cooled for a couple hours....I never took it any farther than that... Just told my bud to get another motor, or plan on an expensive rebuild, the truck sits in his garage now waiting for $....

cjsgarage

word. I checked the compression. 180 all the way around. It's a real healthy engine, just not turning over. no idea what's wrong. thinking the thermal time switch is bad

ExB16ner

check TPS adjustment, my engine ran like crap with faulty TPS

cjsgarage

hmmm. i still haven't got around to calling the individual that owns the 4runner and making a point to go see it. Maybe I can do that tomorrow.

I'm still thinking the problem is in the spark. and I'm thinking the problem is in the timing of the spark--hence dropping the distributor a bunch of times. I'm getting spark on it, just not firing. and adding fuel does nothing to the problem. I want to check to see if maybe the cold start injector is flooding out the truck.

anyway. I will try to call him tomorrow to see if I can try to tinker on it a little more. I would hate to see a car beat me, much less a Toyota!

PatrickWJ

Did you figure it out? I'm having the exact same problem and it is highly frustrating

spurlockda

OK, similar as everybody else. 93 4rnr v6 injected. Pulling out of a parking lot driving slow around the lot no shut down. engine died like it ran out of fuel. Have good spark, good fuel at fuel bar, good compression, checked tdc at number 1 plug. No check engine lights, sprayed carb cleaner in intake no luck. swapped computers, mass flow sensor and something else but my head hurts so bad now I forgot everything. This one has kicked my ass. Any ideas? I've seen posts about cold start relay and etc. will check that tomorrow. Gonna check O2 sensor line agains exhaust. I can't think of anything else. I'm starting to cuss Yotas. too friggin complicated. I got an 87 long bed deluxe and stripped the 22r down with a webber carb and no vacuum lines. Basic motor - LOVE IT! Help me fix this 4 rnr please?????

ammonhotep

I'm surprised there's no resolution on this thread.

My 1994 4Runner (6 cylinder, 3.0 liter 3VZE) has the same symptoms others describe -- After sitting for a while I may get a cylinder or two to fire, but it quickly floods. No start at all.

Bought it non-running for cheap. Former owner said he pulled out of the driveway, and it died like someone turned the key off. It sat for 4 months before I bought it.

I towed it home and replaced a number of parts: battery, plugs, plug wires, cap, rotor, ignition coil, igniter, Mass Air Flow Sensor (MAF), Circuit Opening Relay (COR), fuel pump, fuel filter, and a couple fuses. All are tested and working. I uninstalled the (dealer installed?) alarm system as it wasn't functioning anyway.

I have spark, compression, and fuel. I also tested the following: timing, distributor pick-ups, starter relay, ignition switch, throttle position sensor, EFI relay, all six VSVs (fuel pressure, EGR, Pair Inj., etc.), as well as numerous connections to/from the ignition switch (EFI relay, COR, MAF, fuel pump, etc.). All are within spec.

Symptoms remain the same as day one. I'm really hoping that bumping this thread will bring some answers forward. In the meantime I'll be checking the cold start timing, and Coolant Temperature Sensor (CTS). After that the only options I can think of are the main ECU and the EFI ECU.

Any ideas?

scope103

If it is flooding you could have a stuck-open injector, a failed Fuel Pressure regulator (rail pressure too high), or even a stuck-open cold start injector. After a failed start, when you remove the plugs are they all wet? (or all dry?)

Have you tried starting it with starting fluid? (do this only as a last resort)

ammonhotep

Ok, we figured it out.

The problem was that the timing belt had skipped several gears on the driver's side cam (cylinders 2,4,6). Because the passenger's side cam was still aligned, the timing appeared to be good by normal means of testing. Of course the timing was good, but for only half the cylinders.

We diagnosed the problem by feeling the air pressure at the intake. It would alternate suction and then a kick back. We confirmed the diagnosis by pulling the timing cover and looking at the factory timing marks on the cam pulleys relative to the marks on the rear timing cover.

Not sure why this is causing the flooding. Could be mixed signals being sent to the EFI ECU. Could also be a different problem I'll have to deal with later.

Lesson: don't use inferior parts or your timing job will only last 21k miles. Going to the shop now to get a new timing belt (OEM) and timing belt tensioner. For more information on the timing belt replacement, this is a great thread: https://www.yotatech.com/forums/f116...s-pics-183911/

-Ammo

EDIT: Problem confirmed. I replaced the timing belt, tensioner, and idler pulley. Put it back together, and it started right up! I've heard this same problem happens more often (or sooner) when people use cheapo belts. Got my OEM belt for $53 at the local dealership. Napa had the least expensive idler pulley.

TRINI MIKE

I have been following your great forum for some time now, but this is my first post. I have a 94 4 runner 3vze engine with the same problem. Spark to the plugs, fuel to the rail will crank but not fire at all. Here is what i have done so far:

Dropped the tank tested the pump and it runs fine.
Changed the fuel filter.
Changed the AFM.
Changed the coil and Igniter
Changed the fuel pump relay
Jumped the fuel pump
Changed circuit opening Relay
Was running down a hill it cut out and has never started.
Timimg belt ok and timing dead on.
Please help if you can.

ammonhotep

Timing may be correct on ONE side (#1 cylinder), but if the timing is incorrect on the even numbered cylinders, the engine won't run. Checking timing with a timing gun will only give you info on the odd numbered cylinders.

Simple test: Put your hand in the air intake and crank the motor. If the 2-4-6 side is off, you'll feel a push/pull of air, rather than just a pull.

If you feel an alternating push/pull of air, confirm by pulling the belt cover and checking alignment of the timing marks on the cam pulleys.

If it's not that, I have no other idea to help you.

scope103

If you have spark to the plugs and fuel to the rail, why did you change those parts?

First, how did you test for spark and fuel (and under what conditions).

Assuming (sensibly) that you are correct, either the plugs are firing at the wrong time (have you checked ignition timing?) or the injectors are not opening. (you can sometimes check for that with a stethoscope as the injectors audibly click, but that can be difficult with a no-start-at-all situation. So either get a commercial "noid" light or rig one up with a cheap LED and 1k ohm resistor)

TRINI MIKE

Ok. After all the changing of parts and monitoring for the forum for a week I think I am close to the solution. While cranking and then switching of the key I realized the engine would fire once but in the wrong direction. Indicating a timing problem. I advanced the distributor as far as I could and it started right up but running rough. I think this tells me the belt has slipped a couple of teeth on the cam opposite the distributor. I have checked the timing over and over again and it was ok not realizing at that time it could have been out on the other side. I will pull the front cover tom and let you know. I changed the belt and tensioner 6 months ago so did not think to look there. They were not original parts, naybe that was the problem. We will see.
Thanks for the help Guys. This forum is great!!