That's the Techmate. good little unit.

I really need to get me one of those.

It's an easy check. I keep a space IAC on boat at all times. JIC. They fail that often. Yes, running on a bad one will eventually burn up the IAC driver in the PCM. With a scan tool you can monitor your IAC operation while running and do an IAC test of the valve.

https://cimg0.ibsrv.net/gimg/www.off...6831aadcb5.jpg

Wildman,

I just ordered one. I know, I know... I shoulda done it a couple weeks ago. I'm not sure it would have helped, though. It does allow for a cylinder misfire sequence, but I'm not sure if it will do either/or ignition/injector deletes independently or not. I guess we'll find out when it comes in.

I'm hoping to not need to use this any time soon, but we all know what boat ownership entails, don't we?

Thanks. Brad.
(937)545-8991

Ryan, others....

What are the chances that that's exactly what is causing the idle hunting I'm seeing with my boat.....?

Thanks. Brad.
(937)545-8991

Yes, you can fire coils and injectors independently. I relocated my IAC input hose to pull filtered air from back of intake. Capped off port in throttle body.
https://cimg1.ibsrv.net/gimg/www.off...a0465e3c12.jpg

The IAC counts increase when you back off the throttle the IAC opens to keep a smooth transition air supply into the engine while the rpms come down and keep it from surging or stalling. When its back idling at 650 rpms the IAC counts go to 0 as its not needed and it waits for its next needed operation.

The short version is #7 injector was randomly stuck at about 20/30% flow and #4 was consistently 20 % or so low. Its a miracle that #4 didnt melt the piston and detonate itself to death being lean under boost! I extensively cleaned the injectors then cycled them for about 2 hours almost constantly on my machine on inductance test setting to make sure they didn't decay hot or act up again, then ran all my series of test, they were well within spec once cleaned, Smitty

Guys,

Gonna hopefully test the "new" Bravo 28P prop this weekend. In the event it's not enough (as I'm expecting), I am exploring options. There is currently a set of Hydromotive P5-X 26P props for sale in the Swap Shop. Price seems reasonable, and there's already somebody interested in the LH only, so we should be able to work something out if I can make use of the RH. I understand that Hydromotive props generally act like a Bravo of a couple inches more pitch, so this might be right in the sweet spot. Really looking for guidance on bow/stern lift characteristics re: single stepped hull. Yes, I know about the difference in slip and that effect on a stock B1 outdrive.

Refresher.... PowerQuest 280 (single stepped hull), advertised (by ProCharger) 615HP (zero manifold pressure @~3800-4000RPM). Buried the rev limiter with a Bravo26P well before burying the throttle.

Thoughts?

Thanks. Brad.
(937)545-8991

what's your current speed vs rpm? I owned one of these last year and I've either tuned on water or built, dynoed then tuned 4 others on water. Very sensitive to weight in the cabin and getting bow loose for speed but they run flat. We ran 77/78 gps sunday with last one with 26 pitch at 6 k, he had slot of weight in cabin, this week he ran 77/78 ,×with a 30 labbed at 5400 with 3 big guys in boat. Im.interested in what prop works for you.

Guys,

Prop search is over. Tested the Bravo28P this afternoon, and it is the prop we are going to run. It was slightly less lively than the 26P coming on plane, but loaded the engine at WOT just about perfectly. I could just get it to 5K RPM with the right amount of trim, and saw 75MPH at that point. The boat had a slight bit of slow chine walk that I was able to settle down with just a hint of tabs.

I plan to hang onto the Bravo26P for use when we’ve got a number of people with us or when we intend to pull a skier.


Thanks for all the help and advice in this thread. And hopefully, it can serve to guide others in rooting out similar problems.

Thanks. Brad.
(937)545-8991