RAV4 intermittent start failure

[scottdac]

For about two months, our 2002 Toyota RAV4 (37000 miles, automatic tran) has occasionally failed to start. It always turns over, but either does not start at all or starts for an instant and then dies. After failing to start (anywhere from 1-5 tries), it will usually start after either a short period of time or (sometimes, it seems) if we move or jiggle the shift knob. Much of the time it starts just fine, and there is no way to predict when it will not start.

We first took it to 2 different Toyota dealers for service. It stalled out once at each, but they were able to restart it and also unable to duplicate the problem again. The first Toyota place cleaned the throttle body and fuel injectors - this did not help. The second Toyota place were unable to find anything to fix because they could not duplicate the problem. In each case, nothing came up on the diagnostic computer.

Next we took the car to a mechanic, who switched the fuel pump (C/OPN) and EFI Main relays with 2 less-used relays and the problem seemed to disappear -- for about a month. Then, after a two-hour drive and shutting the engine off for maybe 10 mins - i.e., still warm - the problem recurred. At this point we switched the C/OPN and EFI Main relays and the car started right up. We then replaced the C/OPN and EFI Main relays with two new relays. The car started up OK for a week, then once again began intermittently not to start.

We purchased an extended warranty that would appear to cover this problem -- if we could figure out exactly what the problem is.

Would appreciate any feedback as to what is causing the problem, and what course of action we should take with Toyota service people and/or Toyota extended warranty people. Thanks.

[daredevil1]

I am having the same problem. Sometimes my 91 Celica wouldn't start but would turn over and eventually I would get it to start. But now it stalled while I was driving and I can't get it to start back up but it cranks.

[da_jazzee]

Jiggling the shift knob and then starting would be indicative of the shifter position sensor in the trans, but it would appear totally dead (no cranking cause it's not suppose to crank unless it thinks it's in neutral or park), then you move the shifter and it cranks like crazy. Not starting as in, cranking fine but not starting could be a throttle body, or many other things: vacuum problems (which might also explain starting and then stalling, bad ignition wires (spark is inconsistent or weak), fuel problems (pump, filter).

[daredevil1]

The rotor isn't turning and it almost sounds like the flywheel is spinning really fast and not engaging. Not saying that's what it is but it just sounds really unusual. The belt for the alternator and everything still moves.

[ChiTDI]

[ "Next we took the car to a mechanic, who switched the fuel pump (C/OPN) and EFI Main relays with 2 less-used relays and the problem seemed to disappear -- for about a month. Then, after a two-hour drive and shutting the engine off for maybe 10 mins - i.e., still warm - the problem recurred. At this point we switched the C/OPN and EFI Main relays and the car started right up. We then replaced the C/OPN and EFI Main relays with two new relays. The car started up OK for a week, then once again began intermittently not to start."

Can we clean the grounds in this circuit?

[Earl43P]

The next time it doesn't want to start, try this:

Turn the key to Run, but do not crank the starter. Listen for the fuel pump, it should run for about two seconds. Turn the key back to Off.

Repeat this three or four times, THEN crank the starter. It should start immediately.

If this works, you may continue to use this procedure as necessary or you can have the fuel pump replaced. The fuel pump assembly contains a check valve. Its purpose is to keep the fuel pressure from bleeding off while the engine is off. Turning the key to Run makes the fuel pump run and re-pressurizes the fuel rail.

I can't even BEGIN to tell you how many times I have told people this when they ask me why their car is so hard to start after sitting (usually overnight).

The key factor being "Can you hear the fuel pump run when the key is first turned to Run".