Weird problem with my 4runner

[swampycu]

So, I have a 96 4runner that I have owned for about 5 years now and it has really given me no problems up until now other than a head gasket leak I fixed about a year ago. its only got 184k miles, so not even crazy high mileage. I have also scoured this site and others and cannot find anyone describe exactly what I got wrong.

The problem: the car randomly dies while running and occasionally will not start. If it wont start, it turns over, just won't fire. The fuel pump seems to be running as I can hear the faint whine. when it dies, there is no warning and no unusual driving conditions. Sometimes it will run for an hour with no issues, other times in dies within 15 minutes. It also never throws a CEL code.

What I have replaced so far:
Vapor canister
fuel pump and strainer
fuel filter
Throttle position sensor
Mass air flow sensor
Idle air control valve
I have also looked for loose wires and cannot find any

At this point I have no idea what to try next. Part of my problem is that it does not seem to be consistent. As an example, I ran it for an hour yesterday, started it multiple times and ran it around the neighborhood - no problem... I go out today and it sputters and dies immediately, then after a few tries it starts and runs for about 5 minutes then dies and will not start back...

Any advice is greatly appreciated.

Thanks
Brian

 

[Skulking]

So, I have a 96 4runner that I have owned for about 5 years now and it has really given me no problems up until now other than a head gasket leak I fixed about a year ago. its only got 184k miles, so not even crazy high mileage. I have also scoured this site and others and cannot find anyone describe exactly what I got wrong.

The problem: the car randomly dies while running and occasionally will not start. If it wont start, it turns over, just won't fire. The fuel pump seems to be running as I can hear the faint whine. when it dies, there is no warning and no unusual driving conditions. Sometimes it will run for an hour with no issues, other times in dies within 15 minutes. It also never throws a CEL code.

What I have replaced so far:
Vapor canister
fuel pump and strainer
fuel filter
Throttle position sensor
Mass air flow sensor
Idle air control valve
I have also looked for loose wires and cannot find any

At this point I have no idea what to try next. Part of my problem is that it does not seem to be consistent. As an example, I ran it for an hour yesterday, started it multiple times and ran it around the neighborhood - no problem... I go out today and it sputters and dies immediately, then after a few tries it starts and runs for about 5 minutes then dies and will not start back...

Any advice is greatly appreciated.

Thanks
Brian

It's not throwing a CEL, but have you actually hooked it up to a scanner and tried to pull codes? You should be able to pull pending codes as well even if it hasn't actually thrown a CEL yet.

Do you know what the age of your plugs, plug wires, and ignition coils is? Not saying that is the problem since I would think it would take more than a bad plug to cause the engine to shutdown, but it would be good to rule those out.

 

[swampycu]

Yes, I have a scanner and have hooked it up multiple times. No codes saved in the system.

The plugs are not too old as I have replaced them since owning it and really haven't put many miles on it in since. I am not sure about the coils. My thought was that if it were these, it should be throwing a code. Is this correct?

 

[cashflow50]

Somethings gotta be loose. Just a thought. My cousin has a 00 TR4 that he brought to my house one day and after an hour or so of parked, he went to start the car. Couldn’t start at first. He tried firing it up and finally started. After a minute or so it sputtered and died. He said his battery cables were loose. I thought to myself how can cables be related to engine dying. Sure nuff I took him to O’Reillys and bought new battery connectors along with a new battery. The problem was that the post circumference on his battery was too small for the connector. Installed and wallah she’s alive again. Not saying it’s the same problem but worth checking if they are nice and tight


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[HiLife]

Next time it just turns over and over and doesn't want to fire, have a partner/friend spray engine starting fluid in the intake.
If it fires right up, you know where to look next.

 

[nissanh]

A car stalling without a code is most likely is your fuel pump. Do what "hiLife" said above. You can also listen for the pump when it stall next time.

 

[cashflow50]

A car stalling without a code is most likely is your fuel pump. Do what "hiLife" said above. You can also listen for the pump when it stall next time.

He mentioned that he already replaced the fuel pump and strainer. How long ago don’t know, but he did say he changed it


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[swampycu]

thanks for the replies.

All the parts listed above have been replaced since this issue started 2 months ago and I have driven the truck ~10 miles since then. Its been a long process of buying a couple parts, waiting for them to come in, figuring out a time to work on it, replacing them, seeing that it doesn't fix the problem and try to figure out a next step.

I thought it was the fuel pump too, but the problem didn't change after replacing it. Friday when it wouldn't start after my latest round of parts, I could hear the whine of the fuel pump while it was turning over. I worried it might be the wires in the tank, but when I replaced the pump, they looked good with no corrosion. my next step was going to be to drop the tank again and replace those wires, but after hearing the pump working and no firing, I dont think thats it.

I have checked the battery connection and they are tight, but I do have some corrosion. maybe that's causing issues?? ill try taking those connections off tomorrow, cleaning it up real good and see if it makes a difference. I think the battery itself is good as it never has a problem turning over the truck no matter how long i try to get it started.


In the back of my mind, I am worried I have some intermittent wiring issue, and that feels like an impossible thing to track down.

 

[pelantire]

Have you cleaned the grounds to the motor block? Fuse box grounds?

 

[billyblunk3]

Did you change the fuel pump with an OEM one? I had a shop change mine about 4 years ago and they used aftermarket which gave me constant problems like you are describing. Ended up needing fuel pump and sending unit from Toyota. Not to mention they hooked lines up backwards to my evap canister flooding it.


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[Coondog#1]

I have a 96 that would randomly die. Had a missfire code. P3000 or something. Eventually pulled the ECU and popped it open and some of the capacitors were busted and leaked into the board. Did some research and it was a problem in older Lexus cars mainly. Replaced the capacitors and resistors I think they were called. soldered them in and cleaned board with alcohol. Hasn't missed a beat in 3 years. I've read about it in other 96s too.. Worth a shot.keep us posted

 

[gamefreakgc]

Have you cleaned the grounds to the motor block? Fuse box grounds?

Agree with this. Clean all grounds and ground wires with rubbing alcohol and give those battery terminals a nice baking soda bath to break down that battery acid. By the way, if your battery is leaking acid it's about to fail.

The grounds to clean are: battery to fender ground, passenger's side cylinder head to ground (may also be on the upper intake plenum), engine diagnostic port to intake plenum ground strap (this one gets really dirty) and if you can do it, ECU to ground.

The sensors that can cause the engine to stall are: Idle Air Control valve, Mass Airflow Sensor, Crankshaft Position Sensor and Camshaft Position Sensor. Not saying you have to replace these but hoping it helps in your search after cleaning the grounds.

 

[pavelvoivoda]

As gamefreak mentioned, check your grounds, especially the ones to the ECU. Usually if engine turns off suddenly, without warning it may be an electrical problem, possibly due to rust.

It happened to me and my dad while driving on the I95 near Boston one day to work.

It turned out to be a rusted ground wire that broke off! They dont call it a rust belt for nothing!

Here are the diagrams for 3RZ and 5VZ engines. I didn't see which one you have, but check the points with the triangles.

 

[762NATO]

Any updates - did you ever solve your starting issue?