PT Cruiser GT

[KBzPTGT]

Hello all. I have a '03 PT Cruiser turbo autostick. I've run into a injector duty cycle issue. At WOT, the injector DC is over 110% or more at 17psi. Unless I have fuel pressure a problem, it should be 58psi. This just started with the addition of the upgraded turbo. I'm just curious about the hi duty cycle. Bad injector? or FP?

Here's my list of mods:
MOPAR s3 turbo/manifold/wga
MOPAR s1 pcm
MOPAR s2 injectors
Walbro 255 fuel pump (rewire waiting install)
Psi-Fi PPQ (SMT6d) fuel controller
3" o2 housing & exhaust
AeroForce scan gauge
AEM wb
30/30 boost gauge


Thanks,
KB

[glhs0426]

OK, I've got to ask. How can you have over 100% duty cycle on the injectors? 100% is full open, constantly spraying fuel. What is showing you 110%?

[KBzPTGT]

Thanks for the reply.
I have an AeroForce scangauge.
www dot aeroforcetech dot com
It plugs into the OBD connector. 100% is 100% so that is why i'm confused as to why it shows 110% or more at times?

KB

[Matt Cramer]

Not too familiar with the inner workings of your particular ECU, but I've seen others like the Megasquirt report a duty cycle of more than 100% if you need more fuel flow than the injectors are able to deliver. The MS goes by what the pulse "ought to be" instead of what it really is, and anything over 100% (in practice, anything over 95% or so) isn't really happening. I'm not sure if a ScanGauge does the same thing or not. But I'd check the fuel pressure first.

[glhs0426]

Quote:

Originally Posted by Matt Cramer Not too familiar with the inner workings of your particular ECU, but I've seen others like the Megasquirt report a duty cycle of more than 100% if you need more fuel flow than the injectors are able to deliver. The MS goes by what the pulse "ought to be" instead of what it really is, and anything over 100% (in practice, anything over 95% or so) isn't really happening. I'm not sure if a ScanGauge does the same thing or not. But I'd check the fuel pressure first.

Matt,

Thanks for clearing that up. I'm getting ready to tune my MS and that's good information.