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Toyota Service
Toyota Service, Toyota Expert
Category: Toyota
Satisfied Customers: 4529
Experience:  30+ Yrs of auto experience, Award Winning Svc. Manager; Just Answer Customer's Choice Award Winner
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Idles fine tell I give it gas what it the first step

Customer Question

Idles fine tell I give it gas what it the first step
Submitted: 5 months ago.
Category: Toyota
Expert:  Lou P replied 5 months ago.
Hello. The first thing I would think would be a failed throttle position sensor or a huge vacuum leak or failed mass air flow sensor. Do you have a check engine light on ? How did this start ?
Customer: replied 5 months ago.
It ran fine then broke down it broke timing belt put new kit on then that's what happened little bit of ruff idle but will idle for hours but soon as give it gas cuts off anytime idle speed change
Expert:  Lou P replied 5 months ago.
Oh no, ok so have you done a compression test ? It's possible you bent some valves. That is the first thing I would want to know before we go any further is if compression is good all across the board.
Expert:  Lou P replied 5 months ago.
Even though it idled fine a issue can be bent valves , a loose vacuum at the map sensor or a faulty mass air flow or misadjusted tps.
Customer: replied 5 months ago.
How can I tell if it is a bad sensor I need to have it scanned I guess
Customer: replied 5 months ago.
A non interference can still bend a value
Expert:  Lou P replied 5 months ago.
Sometimes the easiest way to tell if you have a bad sensor is to unplug it while engine is running and see if it changes anything better or worse
Customer: replied 5 months ago.
Is mas sensor on air intake tube
Expert:  Lou P replied 5 months ago.
since the only thing that happened was the timing belt broke that tells me that something is loose or disconnected. So we may not even have a bad sensor but we need to try a few things in order for me to understand what may be Happening. What size engine do you have ?
Expert:  Lou P replied 5 months ago.
What is happening is when you press the gas the computer is not seeing the throttle open or it's not seeing the airflow coming in or it's not seeing the manifold pressure raise in order to add more fuel. Or you simply have a loose ground. We should be able to figure this out. But you may want to run to Autozone and rent a scanner. It's free you just pay a deposit.
Customer: replied 5 months ago.
3.4 won't stay running at all this morning starts then cuts right back off
Expert:  Lou P replied 5 months ago.
ok so maybe temperature is affecting it as well. how long does it run before shutting off? and does giving it gas make it better or worse?
Customer: replied 5 months ago.
Yesterday when warm it started right up only runs for a second or two
Expert:  Lou P replied 5 months ago.
ok i will have to opt out at this point my apologies.
Expert:  Toyota Service replied 5 months ago.
Hello. Different expert here. Please allow me to add input. First, when it does idle, is the check engine light on? I do not see where you said it is on or not. Please advise.

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