When.It.RunsIt.Runs

I bought a 95 toyota 4runner 3.0 auto the beginning of this year. It needed a lot of little stuff done to it. I knew it wasn't perfect when I bought it and that I would have to spend a great deal of time on it. The one issue I have never been able to trace down is the bad starts at operating temp. I've searched a lot of these and made many facebook posts that haven't pointed to a working solution. Cold starts are never an issue. When I drive around town and leave it parked for about 20 minutes it doesn't want to start for me. I usually start it with my foot to the floor and sometimes it will pull thru (rarely). It fires for a second or two then dies. Usually the first attempt at this is the strongest. Recently I have bought a can of starting fluid to get it running. I am normally alone driving it, so I will spray a tiny spray in a vacuum line, reconnect the line, drop the hood, foot to the floor, turn the key, and then it will run like trash before it straightens out. After that little session it will run fine. Today I had to have the wife crank while I had the throttle held wide open from under the hood while spraying into the crank breather line. This was the process I had to run to leave a gas station. After that it ran like a top for about 110 miles.
My efforts to fix/trouble shoot. I'll try not to leave anything out:
1. I've ran supreme in the truck since I've owned it
2. Fuel pressure regulator and filter replaced
3. I've jumpered the fuel pump in the diagnostics box with no change
4. I had to set the distributor to the correct timing since I guess the guy I got it from thought retarded 35 degrees would make it run
5. New air filter and plugs
6. I've cleaned the injectors and throttle body
7. I adjusted the tps with the TB off the truck so I could make the little changes
8. When I open the flap in the VAM it activated the pump. I've also cleaned the sensor inside the unit.
9. I've checked hard for vacuum leaks using a couple methods and can't find any
10. I adjusted the hot idle screw down a little because it would idle at 1500 rpm
11. I've ran it with and without the EGR blocked and plugged

Hopefully I didn't leave anything out. None of these things made any difference with this issue. They affected the overall drivability but never this main issue. I've spent so many hours reading and testing but can't really get any change in it. My next step is to take it to a dealer or a Toyota specific shop. I've read that this could be an issue with the COR, VAM, the regulator, the filter, the injectors, and the fuel pump. The puzzling part is that it runs so good when I start it from cold and when I drive it so I have a hard time believing its the pump. I don't wanna keep throwing parts at it but I also don't want to be stranded. I don't mind buying the fix for it and I plan to use OEM for whatever the replacement is but I don't wanna fix something completely functional. If anyone has the magic words or the solution is be greatly appreciative. This is my last effort before paying out to have someone else troubleshot.

thook

i would start by testing the engine coolant temp sensor. run a forum search on that. covered a bunch

otherwise, i know 22re's due to their design could experience starting difficulties called "hot soak" condition. you know, you've been driving for a bit, stop somewhere, and then it won't start until it cools back down. but, the 22re has a vacuum switching valve in line to the fuel press. regulator to help keep pressure up in this condition. i do not recall if the 3vze has the same design, though

edit: all the switching valve does is prevent the regulator from opening. next time you have trouble starting it while hot, trying clamping the vacuum line to the pressure regulator. worth a shot

When.It.RunsIt.Runs

Is the coolant temperature sensor the one that controls the guage in the dash? Is it the 2 prong connector? I know there's 4 sensors within a few inches of each other on that brick above the firewall.

thook

that's the sending unit that controls your gauge. the temp sensor is the big one to the far right on that cluster of sensors. again, run a forum search. there's images and ways to test it. you'll need a digital multi meter, though. see if someone you know maybe has one to borrow. otoh, maybe o'reilly rents them out

13Swords

Engine coolant temp sensor ohm values depend on temp. Check the chart in this post: https://www.yotatech.com/forums/f116...fusion-291033/

STOP running Supreme/Premium gas in your truck. Nearly every Toyota engine (except for the new Supras) is designed to run on regular 87 octane. You're spending money you don't have too and possibly helping to carbon up the engine with that slower burning 91 or 93 octane gas. The 3VZE only has a compression ratio of 9.0 to 1, which isn't nearly high enough to take advantage of what a higher octane gas could give you. Just for comparison, the Supra engine call for Premium gas but those engine are turbocharged and have a compression ratio of 10.2 to 1.

When.It.RunsIt.Runs

I'll keep that in mind now. I had always been told the supreme was closer to the 100% gas available when these vehicles were built.
Update on the temp sensor: I guess it tested bad because it came out in multiple pieces. I put a new one in the next day and so far (fingers crossed) it will start even at operating temp. This might be the fix.

13Swords

Yep, a busted to pieces sensor just might be the cause. I also hope that this is your fix.

Almost all unleaded gasolines these days are mixed with Ethanol, with the Ethanol being up to 10% of the mixture, regardless of octane rating. I don't know about where you are, but all the gas pumps in my state that dispense "gasahol" have to have a sticker on them saying that it contains up to 10% Ethanol. Personally I run 100% gas in my '78 20R that I get from a local Wawa convenience store. 4 of their 20 pumps have the 100% gas on a separate hose & nozzle. They get away with this by marking it as "boat fuel". You can check out https://www.pure-gas.org/ to find a list of stations in your state that sell non-ethanol gas.

When.It.RunsIt.Runs

I tried testing the coolant temperature sensor. When I touched the connector the sensor broke in half. I replaced the temp sensor and it seemed to be the fix for about 2 days then I started having the same problems again. I think it was just coincidence that it was starting fine. I took it to the dealership and their $100 word was that I needed the mass air flow sensor (equivalent) replaced. I found one at a NAPA store and installed it in the parking lot. No start. It drove a lot better with much more power when I finally got it running. Still nearly impossible to start at operating temp.

Co_94_PU

iTrader: (-1)

The first thing to check is the FPU system. Thook touched on this earlier. However you don't clamp the vacuum line. You want to unplug the vacuum reference line from the fuel pressure regulator and plug/cap the intake side. This exposes the regulator to normal air pressure and maximises fuel pressure, this is what the TSW, FPU signals and vsv do. If this solves it pull the TSW scrub the scale off the sensor and housing and verify the water outlet has a good ground. A follow up check is the TSW switchs to ground when warm. Farther down the line is the FPU signal reaches the VSV and that the switch valve operates, its vacuum lines are in the right order, and the filter isn't plugged.

There are a few other things that come to mind.

Are the plugs wet and if so with fuel, oil, or coolant? Leaking injector (s), leaky valve seals, bad gasket..

Compression checks, cold vs hot and hot dry vs hot wet? Indicates worn rings-cylinders..

Spark test the Ignition cold vs heat soaked, this is a tool that goes inline the cable and has an adjustable gap and scale. You'll compare the spark's color hot vs cold.

PS Toyota should have done all this but obviously didn't if they recommended a refab vafm and called it a MAF.

When.It.RunsIt.Runs

Hopefully someone sees this who has had the same issues I have described. It was the cold start injector all along. After countless hours of research and a ton of dead links searched, I was lead to the cold start injector. The truck is clearly getting fuel but I found out it was getting flooded. That's why it ran fine after process of getting it running was over. I first tried unplugging the plug to the injector thinking that would make a difference (it did not). I decided to find out for sure if I was even looking in the right direction. I picked up a m8 x 1.00 bolt from Auto zone and pulled the banjo bolt from the injector and left the plug unplugged. This would show me without a doubt if this was the culprit. This was about four days ago now and I have hot starts every time without an issue. This is great because now I don't get the look from the Prius and Highlander dads at the park as I spray starter fluid into my wide open throttle body when I try to leave.
To anyone who wants to try this I will say have a fire bottle ready and don't do it on a hot engine. Disconnect the battery before loosening the banjo bolt. I disconnected the circuit opening relay and started the truck to try to get the pressure out of the line. It was still pressurized when I cracked it open. I also wrapped a wet rag around the banjo fitting to contain some of the spray, and had a spray bottle of water for extra safety measures.
It does take a lot longer to start in the cold, but this was only meant to be a temporary check. I'm going to look at options to replace the timer/switch because that's what I've read is probably causing the issue. I might even look to wire in a push button switch to run the CSI after looking at the prices for the OEM switch.

Melrose 4r

Still confused...so the cold start injector was leaking, causing flooding and hard warm starts?

When.It.RunsIt.Runs

Yes. It's either leaking or the switch/sensor is bad. From what I understand it's actuated by a temp sensor on the brick that all the other temp sensors are on behind the intake. Either way it starts when it's warm now that I have the whole thing blocked off with a solid bolt.

scope103

Why don't you find out.

Slide the injector out of the plenum (put the real bolt back in); dangle it over a suitable container. Pressurize the rail by jumping FP to B+ (key-on). If the injector sprays, remove the electrical connector and try again. If it sprays with the electrical connector off, it's leaking and will make warm starts very hard. Replace the injector (about $120 ) and you'll be as good as new.

Co_94_PU

iTrader: (-1)

water bottle for a gas fire

When.It.RunsIt.Runs

Water bottle for gas spilling, fire bottle for gas fire.