Did a Fuel Injector Cleaning.`

[George7941]

I used the OTC 7448 canister and a can of their fluid. I monitored injector pulse width with my Tech2, it displays bank average pulse width. At WOT/2000 rpm : before cleaning 17.25 to 17.56 ms pulse width, after cleaning 16.88 to 17.25ms. No difference at idle, pulse width stayed at 3.4 to 3.6 ms.

I know, not much of an improvement, but a pleasant surprise to me none the less since I wasn't expecting any. I avoid cheap gas and for the past few years I have used Costco gas exclusively (talk about a high volume station, even during their slowest times there are multiple cars filling up at any given moment). I think they advertise that they use five times the required minimum amount of detergents.

Perhaps some one can explain why my truck was difficult to start after I disconnected the canister. It took a few 20 second cranks, with no signs of life from the engine before it eventually fired. I tried WOT/clear flood mode and it did not help. I had used 60 lbs air pressure on the canister and turned the shutoff valve on the canister immediately when the engine stalled after it had used up all the cleaning fluid. The fuel system is returnless. I reinstalled the fuel pump relay and cycled the ignition a few times to run the fuel pump and prime the system.

 

[mazdamonky]

It had to reprime the fuel rail i would imagine. If you would have turned the key to the on position and let it sit for a couple of minutes, it should have come up fine.

 

[George7941]

The fuel pump will only run for about 3 seconds when the ignition is turned on, the PCM turns it off after 3 seconds.

I could have used the Tech2 to keep the pump running, though I don't think it would have helped, since it is a returnless system.

 

[Cressida]

My guess would be that you had so much fuel in the intake that it wouldn't fire - even though you mentioned you tried to correct for this.

Did you notice a bunch of smoke out the exhaust when it finally started.

 

[George7941]

I did not notice any smoke but then I wasn't looking for it either.

After it first started I ran it for a couple of minutes to move it and then switched it off. The next start, after an hour, took about fifteen seconds of cranking. Two subsequent starts also took a few seconds of cranking. After that it came back to normal, starting within the first second or two of cranking

 

[Darris]

Are there any live data metrics that can be monitored on a scan tool and checked against specs, which could indicate weather the car could use an Injector cleaning (at a stage befoe there are any noticeable performance issues)??

 

[George7941]

The only one I know of is injector pulse width. If you record it when the injectors are clean then any significant increase indicates possible injector clogging. This assumes fuel pressure and gasoline quality (% ethanol) remain the same.

 

[DriveHard]

The fuel rail was full of air. Because it is a returnless system, the air had no where to go. The pump primed the system, but just pressurized the air which had to slowly be "injected" out through the injectors. When the air was replaced by fuel it started.

 

[George7941]

Yup, that is what I thought. Still, it was surprising the amount of cranking it took, with throttle wide open, to get all the air out.