cgilley

Okay, I have another post about checking timing belts. At the end of day 2, I have not made any sense of why my truck won't start. It's a 96 V6 3.4L with 265K miles. It's the daily commute of a son, and it has been rock solid. The day after Christmas, he started installing a new sound unit.

Yesterday, I was helping him shake out an electrical issue with the new CD player, and we were testing. Start it up I said - he did, it started, stumbled a bit, but ran. Stumbling didn't bother me, it's long overdue for some TLC.

We turned it off and tried to start it again. Nothing. IT cranks strong. Since it is overdue for a timing belt, I was thinking maybe coincidence and it tossed the belt or it slipped. Pulled the cover and verified that the cams are still turning and the timing is dead on (all the dots line up).

Okay, maybe we tripped the security system - locked and unlocked - still nothing.

Checked all fuses (thinking maybe no fuel due to blown fuse for EFI or the computer) - all fuses good.

Hmmm, let's see if we're getting a spark - we are, cylinder 1 is exactly where it should be when the plug fires.

At this point, I am completely stumped. Maybe the computer died - but if so then why the spark? The timing is computer controlled, so....

Unless I have a sudden epiphany, it's off to the shop tomorrow, which I would really like to avoid. Open to all suggestions. The part that has me baffled is the start-runs-off-dead cycle. No middle ground.

I appreciate any ideas any of you may have.

enapa

How old is the battery?

cgilley

A couple of years... not too old.

enapa

I would at least get it tested. Wouldnt hurt.

enapa

Could be fuel pump.

cgilley

I'll have them test the battery.
As to the fuel pump, it *could* be, but I'm a strong believer in looking for the simple thing first. I think I'm going to have to pay someone to help me slap my forehead .

I'd love to tear into this, but I simply do not have the time - too much to do.

JBurt

Are there any codes? Sometimes they don't always light up the CEL.

enapa

Well you or someone outside the vehicle should be able to hear the fuel pump turn on when turning the key to the on position without actually cranking the vehicle. The problem here is that there "could" be many different things wrong. Unfortunately sometimes there is a lot of guessing and maybes when it comes to mechanical issues.

cgilley

Just to close out my question - the good news is that it did it in the garage, not on the road at 2am.

I had the 4runner towed to a shop I relatively trust. You know what I mean... after double checking everything I went over (I left detailed notes, I have no idea if they were read), the shop still could not determine why it would not start. Going back to fundamentals, it's pretty apparent the belt slipped. That was my gut feel based on the way the engine was sounding.

So, belt, tensioner, pully, water pump, cooling system flush, drive belts, hoses... etc. all should be fine.

For the record, the belt was (my guess) 85,000 miles over due <blush>.
So I don't have a problem paying for rendered services.

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The part that has me baffled - when I was checking the timing belt, I had the crank pully pretty close to TDC (about 5 degrees BTDC) and with the timing belt cover off, the marks on the cam pulleys were dead on. How far off before she stops running?

mattbatson

I'd be surprised if it was the timing belt, but I'd like to find out either way.
keep us updated on what your mechanic finds

JBurt

Then you should be surprised. It was the timing belt. Look at the title of the post you quoted.

cgilley

Well, I am still open for suggestions. My semi-trusted shop's mechanics are all bald - they are pulling their hair out - what's left anyway.

At this point we know we have proper timing, fuel, fire to the plugs, and good compression. They verified the air flow sensor is working properly, and the diagnostics on the ECU say it's okay. No codes.

The SOB *still* won't run. It will crank just fine.

I'm pretty sure this unit has an after market alarm system (that has given us trouble in the past). The original owner had this installed when he purchased the car - with fobs - so I'm guessing he had it done at the dealership (boy, did he spend a lot of $$ on this thing in 1996). Anyway, I know nothing about these alarm systems - what could I suggest they look for? I'm supposing that a skilled mechanic would generally know about the alarm systems and how they kill the ignition?

Try to keep the smart a$$ answers to a minimum

enapa

I would think if it was an alarm you could start pulling accessory fuses. I would start with radio and go from there.

cgilley

Agreed. Which raises an interesting and awkward situation... how do I get my 4runner back? I suppose I'll have to agree to pay for something, it did need a timing belt plus hardware after all... but it's not running.

I predict an awkward conversation with the manager

enapa

Tough one there. They did do work on it.

cgilley

yes they did. But it's okay, I'm sure it will work out in the end.
After doing additional diagnosis, we've cooked part of the ecm. We're only getting spark on 4 cylinders, so we're searching for a used ecm now.

Yet another weird repair item - shops hate putting used in a vehicle, but we all know how "special" an ecm is from the dealer.