Rough start and idle in Toyota Yaris/Belta 2009


#1

I live in Trinidad, West Indies and just imported an Toyota Belta (Yaris) 2009. When starting it after it’s been siting for a while (i.e. over night) it almost always doesn’t start on the first attempt, but will on the second, recording attached.

Also, it has a rough idle. Today it idled down so low when we were at a stoplight it sounded like it was going to stall.

We’ve changed the fuel filter, spark plugs, and cleaned the injectors and throttle body. The mechanic has run diagnostics which didn’t indicate anything other than rough idle.

We would be most appreciative of any insight that can be offered.


#2

@“belta owner”

Here’s my gut feeling . . . you have a fuel pressure problem

Teeing in a fuel pressure gauge would give you a lot of answers

All those things you mentioned . . . you did the right thing. That is a very good starting point

Did those diagnostics you mentioned include fuel pressure test(s)?


#3

When it doesn’t start, does it crank ok, but not catch and run? Or is this problem a fails to crank?