Mechanics

WHY ARE THE INJECTORS CYCLING

2005 Scion tC • 135,000 miles

My son's 2005 Scion TC has injector issues. They are not spraying. I have replaced the fuel pump (It was not putting sufficent pressure out) and insured that the line was clear. I had the injectors bench tested and rebuilt. There is fuel to the bar. What would prevent the computer from cycling the injectors at the proper time.
FWIW- he noted that the problem has been getting worse with time (harder to start each morning over about a 1 week period) and now it completely will not start. Also- when I pulled the bar/injector assembly some fuel leak around the ports---it actually tried to start for a moment.
Thanks
Avatar
ColumbusA
June 16, 2012.




A faulty cam sensor circuit or PCM would result in no pulsing of the injectors.

Did you check for trouble codes?
Is the MIL indicating?
Did you test the fuel pressure at fuel rail?

KHLow2008
Jun 16, 2012.
There were no 'check engine' lights on- so I didn't go there. I'm not sure what a 'MIL' is-
Fuel pressure at the rail is excellent- now. The cam sensor was kinda what I was thinking after some research.
I'm old school (points- condensor, plugs and carbs) just never made the transition over to computer based stuff.
Will a standard OBD reader do the job or is there a special model I'll need?

Tiny
ColumbusA
Jun 16, 2012.
The other thing was that the problem was slow in onset- I would have thought that something electrical (ie a sensor) going out would have been sudden and complete.

Tiny
ColumbusA
Jun 16, 2012.
It could just be a dirty sensor, contaminations to the wire connectors or the pickup of the sensor has a fault. Try checking the connectors and note if there are any contaminations.

MIL = Malfunction Indicator Light = Check Engine Light.

Not all code readers works and if it does, it would only tell you if trouble codes are there.

A proper scan tool would be able to show you more.

Btw I am old school too but had to keep up with the times in order to survive, not an option to stay old school. Lol.

KHLow2008
Jun 16, 2012.
Okie-Dokie, went and rented a scanner from O'riely's---
"P0453
Evaporative Emission
System Pressure
Sensor/Switch High
input"
Is what the scanner reported. Ive checked all the connections at what I think is the device. Nothing seems to be out of place. Is there a way to test this thing or is it replace only?
Thanks-

Tiny
ColumbusA
Jun 16, 2012.
I thought most parts stores provides free scanning services?

Anyway I never believed in replacing components without confirming if they are faulty.

The file for this is rather large and not convenient for me to post here. Let me have an email address that I can send to in PDF format.

KHLow2008
Jun 16, 2012.
EF1Nobles@gmail. Com

FWIW---I bought a Noid light set. They ain't flashing! LOL

Tiny
ColumbusA
Jun 16, 2012.
That can mean a bad PCM or it is not getting the signal to fire the injectors.

I just sent the filers, hope it can get through correctly. I sometimes cannot send files that are too large.
AD

KHLow2008
Jun 16, 2012.
What is PCM? Pollution control module?

Tiny
ColumbusA
Jun 16, 2012.
Its the computer ( Powertrain Control Module ) lol> Pollution

Tiny
Rasmataz
Jun 16, 2012.

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