Motor dies temporarily at speed - Toyota Nation Forum : Toyota Car and Truck Forums

Raffky · 12-20-2008, 04:54 PM

I have just replaced head gaskets on my 3vzfe 260k. Initially, the motor would start for a few secs then die. I had a new MAF installed which fixed that prob. Now the motor starts and runs well but when driving on highway, it dies for a few seconds, then keeps running. This might happen every minute or so. It seems to happen more when you back off slightly with the accelerator. Any tips appreciated.

***ASG14*** · 12-20-2008, 05:05 PM

Any check engine light?

Raffky · 12-20-2008, 05:39 PM

no engine light, no error codes.

***ASG14*** · 12-20-2008, 05:45 PM

What do you mean by it "dies"? If it dies, it won't automatically start, you have to turn the key again or pop the clutch.

Raffky · 12-20-2008, 07:34 PM

Revs drop by 500 or so for one or two secs then it goes back to normal speed. No restart or clutch needed

***ASG14*** · 12-20-2008, 07:35 PM

Does this happen when accelerating, cruising, or slowing down (foot taken off gas)?

Raffky · 12-20-2008, 08:13 PM

It happens most easily de-accelerating, also happens when cruising but does not happen when accelerating.

***ASG14*** · 12-20-2008, 09:13 PM

What is the RPM's at idle, when the car is up to temp? I'm almost guessing this is a throttle body butterflt or IAC valve issue. Either the throttle body closing too much, stopping the air, or the IAC (Idle Air Control valve) went bad and not working.

Raffky · 12-21-2008, 01:58 AM

The idle RPM at operating temp is normal. Whole motor operation is fine except brief rev drops when driving, as I mentioned. I will take a look at the throttle body and IAC valve as you suggest. I really appreciate your time and help!

***new echo owner*** · 12-21-2008, 02:08 AM

Check the TPS adjustment, it may have gone into close throttle fuel-cut. Maybe?

N.E.O.

Stillrunning · 12-21-2008, 04:21 AM

Quote:

Originally Posted by Raffky

except brief rev drops when driving

Tranmission may not be shifting into overdrive, but does so once in a while, hence the rpm drop. Make sure you are in OD or not when rpm drop happens. If you switch off the OD and there is no increase in rpm then look to the solenoids in trans.

Raffky · 12-21-2008, 05:19 PM

Quote:

Originally Posted by Stillrunning

Tranmission may not be shifting into overdrive.

Your idea sounded promising but after a test drive, I found OD on or off did not make any difference. Engine still does the cut out. I will check into IAC and throttle. Damn annoying because it runs so well at idle and hard acceleration. After three weekends of heads removal work, I was dreaming of one of those instant, smooth start ups. At least I can drive it to work. Just have to persist and crack this prob.