Hello All,

Being recently introduced to the joys of 4wheeling, I was excited to find that my uncle was parting ways with his 87 4runner, which wasn't running at the time. I picked it up with a great body, good seals, a decent interior, all for $600.

I figured between me and my buddy, we could troubleshoot the problem it was having.

The truck will start up when the ignition is turned, but it will only run for ~5 seconds before the engine dies. It seems like the fuel is being cut out, and we assumed it was the fuel pump.

After much troubleshooting, it appears that the fuel system is functioning fine, and that the cause of the issue is somewhere else.

My uncle tells me he started having the problem out of the blue one day, and didn't notice any particular reason this would happen.

I am not having much luck searching the forums for a similar issue, so I am hoping someone out there can point me in the right direction of next steps.

If you have seen this before, let me know.

Thanks.

 

What engine do you have? Seem like you have the 22, check spark plugs damage, etc. A buddy of mine has the startup problem that it idle roughly so he figure it out that his spark plug was damage. Just my 2 cents.

 

A vacuum leak will do that. Stuck open EGR, too.

 

I have a 22re. Spark Plugs look fine. Hoses seem to be plugged in and no apparent leaks. I will have to check on the EGR.

 

You need to confirm if it's a fuel or spark problem... Pull a plug and see if the spark dying out is the issue.
Vac leaks very often are not easy to see.. You have to diagnose them via spraying the manifold around the hose connections.

 

Does it rev up and die? Or does it idle fine then die? Mine will occasionally rev way (upon starting) then die, but I'll restart it and it's fine. I think it's either a sticky EGR or a carb choke problem.

 

I spoke to a few more folks in my local area, and everyone brought up the Fuel/EFI relay. I am going to pick one up and replace that as my next step. Will post again once done.

 

x2 on the EGR stuck open:

https://www.yotatech.com/forums/f116/help-truck-wont-idle-117256/

Can you keep it running if you give it gas? Timing or distributer position can also cause that but if you didn't have the head apart then that wouldn't be it.

Rob

 

The engine doesn't respond to me pressing down on the gas pedal. It really feels like a fuel delivery problem. Once I replace this relay, I will check the EGR.

I found a few more threads with folks having the same problem, and many referring to the EFI relay, along with a hew others referring to EGR. Sounds like these are the areas to focus on.

 

My two thoughts, First get a noid light that plugs in place of the injector, If the cold start injector is working, you will have enough fuel to fire but thats it. Injectors should have power at all times and the computer controls the ground.
Second it could be the ignition switch is going bad. Try starting it and not let the key go all the way released. If it stays running you need the electrical portion of the switch

 

Another thought would be a bad VFM, initial startup cold start injector sprays, but ECM not getting a signal from the VFM that the engine is running so no fuel from injectors.

 

i vote air flow meter. check the plumbing between it and the throttle body for cracks. that old plastic breaks pretty easy and could be your prob. afm is the same for all 22re year models so if you have a multi meter here is the check.

http://personal.utulsa.edu/~nathan-b...33volumeai.pdf

 

Update:

Replaced the EFI relay, and the battery, since my previous battery was donated to yard work via my buddy's tractor.

Truck will turn over but won't begin to run at all. I am heading back to the Chilton's for tips.

Found something interesting. This cable was hanging down by the starter, not plugged into anything. Couldn't locate exactly what it is, but it is coming out of the same bundle of wires that are located right under the fuel delivery in the engine. Anyone know what this is?



(Camera phone pics)

 

Just ran the AFM check according to the link, and the AFM is good. I don't think I am getting any fuel pressure at all right now. I also ran the diagnostics check for a malfunction code, but my check engine light does not come on at all, even upon initial power up. Thanks for the replies. I will keep on looking.

 

The starting & ilding, then dying when you apply the throttle sounds EXACTLY like your VAFM isn't plugged in or isn't making a good contact. What had your uncle done immediately before it stopped running?

 

that plug is for your a/c idle up vsv. bumps up the idle when a/c is on. not needed at least right now in your situation.

 

Thanks for letting me know - I actually don't have A/C on this rig. I assume this plug is just hanging around in hopes that one day I would actually add it.

 

Have you tryed jumping the fuel pump to run, or opening the AFM to listen for the pump ?

 

Well, I just found this old thread, and I hate when I run into threads that aren't answered. After checking the EGR, EFI relay and a number of other items, I ended up replacing the ECU. A "new" ECU from Nix99 solved my problem, along with a new igniter.

Once the ECU was on, it started up like a champ. I think the 4runner sat for a total of 6 years. It has been running for the last 3 years, and just recently started leaking coolant into one of the cylinders. Not sure if it is a head gasket or a timing chain guide issue. Doesn't matter. It's rebuild time.