Bigkahuna808

Bad news with my runner. I have just rolled on 100,000 last week and the problomes have gone from bad to worse . The truck refuses to start up died out 9 times tonite alone. The key turns over and it kicks on, then suddenly dies off. (sounds weak, but I already replaced the starter not more than 3 months ago). I figured that it might be a problome with the o2 sensors, I repaced them (thanks to the guys over at URD, thier prices rock!!! ). That did not fix it, but they need to be replced anyway. Then tonite when it finnaly got started, I drove for a few miles and came to a stop. Then the engine died out . So I started it up again, and had to apply the gas slightly at stops so I could just limp it home. Then just before I posted this I had to make a run to drop my girl home, and I was having low voltage 12.2, the belts were squeeling for a little bit, and then all of a sudden the squeeling stoped. The voltage went up to 14.2 and it seemed fine. Then the idel problome stated again, and so i had to do the same method to limp the truck home. When I parked it it was either pinging or having some sort of detonation occuring.

So Im no mechanic but this a short list of what I think needs to be fixed, please let me know what you guys think :
1) Replace the temp sensors and thermostat
2) Replace all the belts
3) Replace the MAF

Thanks for the help to all thoes who are wiling. I need to get this thing fixed ASAP, this is my only means of transporation. Everyone on Yotatech Rock!!!

MTL_4runner

Your problem sounds like it is a charging system problem so replacing the above items really won't solve much (except maybe the belts). I would suggest changing the belts just to be on the safe side but the biggest thing is to ensure they have proper tension (ie you should not be able to deflect the belt much with your thumb) on them to run all the ascessories (AC, ALT, PS, etc). Also be sure the ascessories are able to turn freely and if it seems like a bearing is going, then replace that unit (pay particular attention to the alternator in this case). Then check the voltage at the battery with the engine running (it should be over 14V minimum....unless the battery is dead or completely uncharged). Now take it for a test drive and see if it does any better.

I would suggest just cleaning the MAF with electrical cleaner and the theromostat / temp sensors I would just leave alone.

roger

Do the 3.4s have an idle adjustment screw? On my old car, that screw fell out and caused symptoms very similar to what you describe; I had to keep the engine revved at stoplights, otherwise it would stall out.

Might be something to check out, especially before you spend a lot of money on parts.

bamachem

$10 says you have a bad hose giving you a vacuum leak.

another $10 says you have a lose alternator belt.

check your vacuum hoses going to the intake before the throttle body. you'll probally find one off or cracked/broken.

you should also clean the throttle body and maf as preventive maintenance. however, it could also be fouled plugs, plugged fuel filter, or a host of other things.

what have you dont in the last 20k or so as far as maintenance goes?

Bigkahuna808

I'll check for the vacum leak in a few mnuetes, I can just use soapy water for that right? Or should I just listen for the hissing?

Bigkahuna808

I tried to track the leak to no avial. I pulled off my PCV valve, and it rattled, could this be the cause of it? Is it supposed to rattle?

User 051420

Yep, if it rattles it's good.

Check those belts! Squeeling = slippage. The alternator won't charge if it isn't spinning. The belt is really easy to tighten. There's an adjustment bolt on the bottom of the alt. Loosen the one that faces the front of the truck, then tighten the one at the very bottom that points out to the drivers side.

I 2nd or 3rd cleaning the maf.

Bigkahuna808

I guess the PCV valve is good then. Im gonna try can clean the MAF. Could the problome really be that simple?

User 051420

Uh Huh. I've changed my alternator 3 times now, and I can almost guarantee that's why the voltage dropped.

Bigkahuna808

I've had it checked 4 times in the last year. Everytime I check it the alternator is fine. Ive had starting problomes before, but never, this bad. I take it in for diagnostics but no can seem to figure out what it is. I dont wanna go to the dealership and this charge me an outragous amount to just tighten a screw (or clean the MAF).

To clean the MAF on the over elbow style MAF you just spray the contact clearner right into the little crosshair tube? Is this like a little spriz, or is this kind of a heavy application? Then let it dry.

rimpainter.com

A couple little sprays will do.

I pulled mine completely out of the intake tube and used the contact cleaner so I could also inspect it closer.

MTL_4runner

Did they actually replace the alternator? if not what did they do?
It has to be your charging system if it is not a big vacuum leak.
I use some carb cleaner on the hoses to look for vacuum leaks (if you hit a leak it will make the engine idle rise).

As for MAF cleaning.....soak the crap out of it (be very gentle if you use a q-tip to help the process)

Bigkahuna808

The alternator was never replaced. It always was able to charge. I just went to Checkers and bought the contact cleaner $5.90 somthing I paid. I gotta check for the vacum line leak. Which hoses should I check the one tha goes to the airbox, the ones that lead from the PCV valve to the throttle?

Bigkahuna808

I did the MAF cleaning and that helped a little. The idel problome imporved but is still not fixed. I called Toyota and they said it might be the ignitor and they cant check the truck untill March 16. They said its gonna cost at least $500 to fix that.

Anywho this is the problome that remains, the engine doesnt want to start after I drive it. If I let the engine cool down for a little bit, it starts up no problome. But if I try to start it after making a quick stop such as getting gas. The engine wont start after. I have to turn the key rev and hold the gas for a min. or so and everything is fine after that. I guess I got a stupid gremlin living in my engine, any ideas fellas. Thanks for all the help!

speaking of gremlins anyknow where I can get Gizmo the "Mogwai..." window sucktion cup doll for the window? Warner bro store closed here in Hawaii

MTL_4runner

So are you telling me if you floor the gas pedal while starting....does it start then?

Bigkahuna808

Not really floor it but, thats whats going on. For some odd reason it helps. I figure that only work on carb engines, but it seems to work for me. I just press down on the gas bring the rpms to about 3000 hold it, for about a min. And eveyrthing seems fine from there

MTL_4runner

You may have a leaky injector which is filling the intake with fuel before the engine starts. This would explain why a hot start (after a short amount of time) was tough but if you let it sit a while, it will start fine. When this happens, normally, the injector will leak until the pressure in the fuel rail is depleated and then after some time the gas has mostly evaporated or is not in significant quantity to prevent starting normally.

You will definately want to get them checked.

rimpainter.com

March 16th? Wow, business must be good for them.

I think a Multi-meter and FSM is in order for you.

TacomaTRD

what about cold start injector flooding the engine?

rimpainter.com

The 3.4 does not have one. Only the 3.0.