Illusion569

92 4Runner 3vz-e engine.

Okay, so here's what its doing. I go to start the truck for the first time of the day, it runs great...until I shut it off for more than 10 minutes. Then it won't start at all, it acts like it wants to but it wont for 30 to 45 minutes. When it does start back, it has a lack of power and low idle. It will be this way until it cools COMPLETELY down. When it won't start, I checked to see if its getting fire and it is. Sometimes, and I stress sometimes, It will start if I relieve the fuel pressure at the cold start injector point. Its had this problem since I have had it. I have replaced the following parts while correcting a power/idle issue it had, which ended up being a plenum gasket and replacing a kinked fuel line. I need to get this truck back on the road as its essential to my line of work. Note that I turn it off just long enough to run into the store(Under 10 minutes), it starts back up and runs just fine. It kind of sounds like its flooded when it won't start. Compression test showed good compression.

• Fuel Injectors
• Timing Belt
• Distributor cap
• Plugs/Wires
• Water Temp Sensor
• Throttle Body
• TPS
• Plenum Gasket
• Fuel Filter

eddieleephd

Fuel pressure regulator........

Illusion569

Really? You seen this before?

eddieleephd

I have not seen this before myself however I have seen it in a post somewhere, and when you say it starts right up after you release the pressure that tells me that is the issue.

Basically if there is too much pressure when you crank it the injectors put too much fuel in due to the fact they stay open for a certain amount of time, this time is set to a certain fuel pressure and if that fuel pressure is not right you end up with either rich or lean mixture!!

You have done all the other stuff but not the one directly related to the pressure release issue!! So this is the next step even though it may should have been the first!!

Remember I am going off,
"Sometimes, and I stress sometimes, It will start if I relieve the fuel pressure at the cold start injector point. Its had this problem since I have had it."

I believe the reason it will not start the other times is because you already flooded it out.

Otherwise I would point at the maf but that is less likely you should at least clean it before going and replacing the FPR but I would suggest replacing that any how because it relly would not hurt but be renewed, Granted it may hurt the pocket but

Fuel Injectors
Timing Belt
Distributor cap
Plugs/Wires
Water Temp Sensor
Throttle Body
TPS
Plenum Gasket
Fuel Filter

hurt the pocket more than the FPR will !!!

Illusion569

Your probably right, note that all the other stuff I did was not to correct this issue, but another...which is why I didn't make the FPR priority. I had to fix the rough idle issue before I moved on to this flooding issue.

So, I did some troubleshooting which lead me to another question. Am I supposed to have constant vacuum from the small hose going into the regulator? I am not getting any what so ever. If so, maybe the regulator just isn't getting the vacuum it needs to operate. I also traced down where that vacuum line went to, wondering if its connected to the right gadget near the fuse box/passenger side of the engine compartment. I suppose it could only pull vacuum when pressure is built up, if I knew it would help me in the troubleshooting process. It would also help if I knew which gadget was which, the haynes manual is misleading.

Note: I changed the MAF, forgot to list it.

EDIT: Ran it up the road and back, the vacuum does work after doing so, I suspect it has to build up pressure. Also put a steth on the regulator, its making a pulsing sound as it should...though I suppose that don't mean anything. I'll try to change the regulator tomorrow, won't run it until then so it doesn't mess up my crank.

eddieleephd

look here
https://www.yotatech.com/forums/f123/
for Links to Factory Service Manuals part numbers

And yes when your truck starts running you should have vacuum to the regulator this may be your issue.

You did not state why you did the above repairs before but it makes sense.

I would say you should see if there is a clog or a break in the vacuum line to the FPR would be a simple fix.

Illusion569

Really? I was thinking the vacuum kicked on after it built up so much pressure, figured thats what that little switch does that it connects to. I tested this theory by running it up the road, afterwards it did have vacuum. Then again its an old engine and it could take it a minute to build up. With vacuum on the line, I took the fuel line loose from the regulator, no fuel at all and it would seem I should have had at least a drip. I would guess it can't burn ALL the fuel in the rail. I'm going to get a FPR later today unless I find reason to suspect something else before then.

eddieleephd

I believe there should be some and an increasing amount of vacuum to the regulator I could be wrong to some degree look at the FSM in the link I posted or this next one from that same page..
https://www.yotatech.com/forums/f123...umbers-102344/

Illusion569

I put the regulator on today, not sure about the starting issue yet...but I can say I drove about 1/4 mile up the road and then the RPM's dropped to 5 and it started losing power while spitting and sputtering. It's as if someone threw a switch and then it started running bad. It was running good until then. Maybe something is telling the computer wrong once it reaches a certain temperature. Also, not sure if this means anything, but when it idled down, it seems like I smelled exhaust. When we got back, my passenger said he smelled fuel back there. The puzzle continues.

eddieleephd

reset the ECM either by pulling the ECM fuse in the engine compartment or by pulling the negative terminal in the battery and leaving that way for like a minute or so.

The ECM gets used to a certain parameter and uses this to judge what it does so if you reset the ECM it will relearn these parameters and start over!!

Illusion569

Reset ECU, no change. This seems like a different problem now, wondering if the exhaust is stopped up somewhere since I do seem to smell it when it messes up. It happens when it warms up, it didn't do this before I changed the FPR. One thing I did notice is oil in the exhaust, not sure if that would cause this problem considering it has 199k on it (Unless the engine was changed prior to my ownership). The previous owner said the cadlytic converter was gutted. It runs fine, then about 15 minutes into runtime it just has no power, wants to kick into passing gear, sputters, etc. This is weird cuz after I changed the Plenum gasket it ran great for a day, then this. No water in oil, just gas from the defective FPR I presume. It could be that it just ran so crappy before that I never noticed this issue. Thinking O2 as a possibility too, i'm stumped. The 02 sensor activates at warm up, about 10 minutes. Thats about the amount of time that passes before it screws up. I unplugged the sensor, no change, perhaps it needs it and when its plugged in its like its not there. Of course, there are no codes until I unplug it. Like I said, i'm stumped. Probably on a while goose chase, but i'll test the sensor for the heck of it. The computer is throwing a IGN circuit code, yet the coil tests out fine unless its something elsewhere in the circuit. I'm just shooting off possibilities.

eddieleephd

Timing Belt
Distributor cap
Plugs/Wires

I would check the timing marks and the sensors on the timing side!!
As well it may be the o2 sensor from what you are saying...
is it running rich at this point or does it just seem like oil???
Another possibility is the Temp sensor... timing code could be the pick up coils that are in the distributor I believe if you are saying you only have one coil then there would be three pick up coils that sense when to fire...

Illusion569

The guy helping me said it was oil. It has new plugs and wires as well as a new timing belt in which the marks lined up. It also has a new temp sensor. I wondered about the pickup coils, I think i'd have to change the distributor. The computer did flag the ignition circuit one time after it warmed up...not sure if that would cause it to run bad when warm. I checked the spark and it seems okay. I'm going to look into testing the O2 Sensor.

Illusion569

The running problem seems to have been timing, the distributor somehow rotated a bit(I think as this truck has fooled me before by running good and then not). The starting issue is still there however. Here's what it does...

After its been run warm, if its off for more than a few minutes, you go to start it the first time, it starts but runs crappy a minute and dies. After that it won't start at all until it cools completely down...then it starts right up and runs fine.

I did notice the wires coming off the igniter module look like their in poor shape. Changing the harness looks like it would be a pain. Before I do this, it would help if I knew exactly what those wires did, anybody know? The ECU did throw a code 14(ING circuit).

Something else that may or may not be related. Radio and dome fuses constantly blow and sometimes when I start the truck the wipers come on with no way to shut them off short of pulling the fuse. It looks like the Igniter circuit connects with the wipers according to the schematic. Anyway, thought it was worth mentioning.

eddieleephd

so is that autotrans or manualtrans

eddieleephd

on a general basis I am seeing 3 possibilities other than the igniter and wires to it!!
Circuit opening Relay for both at&mt, mt clutch start switch "if you have it try the clutch start bypass switch and see if this helps!!", and lastly the ECM!!

the igniter basically tells the coil to fire then tells the ECM that it does and the tach when at least one does... if there is a broken wire in the harness then repairing this is the fix but now it is all about testing those items to see which is faulty!!! when it wont start test the resistance in the wires to the igniter to check against the resistance of the wires while cold is the best way to see on that front!!!
http://www.ncttora.com/fsm/1990-1995...emci/start.pdf

good luck!!!

Illusion569

I'll do that on the starting issue. As for the sputtering power loss, its back today...did fine yesterday. I'm starting to think my truck has a mood disorder. I know it was warmer weather yesterday, not sure if that has anything to do with it. A friend of mine thinks maybe the truck isn't warming up to the right temperature for it to run right, I don't know. Some days it runs great all day and some days it don't. I do know it ran good after I put Marvel mystery fluid in the gas, then after I ran that gas out and put more in it started messing up again.

eddieleephd

ok as for the weather that will most likely point to a dirty maf and the temp sensor once again!! A BIG SIGN you need to reset the ECM and make it relearn especially after changing things like a clean MAF.