The stock .bin is around 12000,

Just wondering how high you can push it? 13000?

Edit: The unit is "usec" of course

 

Anyone? Whats to stop someone from putting in 30000 usecs. By the way this is for th 747 ecm.

 

It's the weekend!! I'd say folks are doing a bunch of other fun stuff! -g- Actually there is nothing to prevent the value from being anywhere < 499 msec (note scale change).

Myself, I really do not know why it is limited to a max of 12 msec. I always looked at it and thought 'hmm, 12 msec is a lot of fuel', or, hmm, 'maybe they want to keep it under a minor loop cycle'.

The under a minor fuel loop cycle makes sense. If the async fuel pulse overlaps the next async pulse, then the ECM will be losing track of the fuel delivery. A minor loop cycle is 12.5 msec.

As for having fun and speaking of fuel, check out the attached graph. This is what happens when the FPR pintle is dragging on the seat. Improper spring geometry.


RBob.

 

With a proper FPR spring it all works out better. . .

RBob.

 

Thanks rRob, BTW I like talking in micro units. Am I right in think that the pulse is async when at high rpm WOT.

Ryan

Also how did you data log fuel pressure? Do you have a digital gauge?

 

rRob, Just out of curiosity, DO you have I backround in EFI, ie: process engineer?

 

Hey Low since when are we at 4300 ft? Did you finally buy a G-tech?

 

Its like 4278, or close to 4300

 

And I think red deer is over 4300 ft

 

No I don't own a gtech but theres one in bargin finder for $150 used that I might buy.

 

I just looked it up to be 3300 in Calgary
You should check out some of your other posts lately

 

I already did! Why don't you change you address on this site from the neonet one to the shaw one?

 

I can understand that you like usec. The only reason I changed to msec is that it is common for injector PW's. That's all.

It is at low PW that the ECM will switch to async mode. Unless of course the cal forces async all of the time (yes, there are some that do). So, in general at high RPM the ECM will be in sync mode (again '747 here).

As for the graphs, yes I have an electronic FP sensor. Installed and have it working this past week. In trying to tune I've run into too many problems that I have felt were due to fuel pressure (first graph comfirms it).

I have become a firm believer in data logging. In this case I purchased a pressure transducer and built the electronics to interface it to the data logger. The electronics are a simple instrumentation amp from a National Semiconductor app note.

RBob.

 

Why was the one spring bad exactly? Did you not use a closed and ground spring or was it something else?

 

That was it exactly. These are homemade springs. The troublesome one was not quite square/parallel etc. . .

So I just developed/tried different techniques until I was able to produce nice ground square ended springs. It is amazing how much better an engine runs when it has an even supply of fuel.

RBob.

 

I was about to make my own spring until I got hooked up with a few for free.
Where did you get the electronic FP sending unit and for how much? It would be VERY interesting too see how well my vacAFPR is working compared to TPS.

 

I purchased the transducer from Digi Key, pricey at $77. I kept looking around and really couldn't find anything cheaper. This sensor (SenSym #19C030PG4K) is all stainless steel with an 1/8-27 NPT port. Have to be careful when dealing with fuel. Other sensors have components that are exposed to and will not hold up to gasoline.

I had to add an amp to it (used a quad LM2902 op amp) before running it into the data logger.

I have had so many fuel delivery problems the cost became trivial. Bad pumps, clogged filters, debris in the regulator, varying regulator pressure, liquid filled gauges. . . Can't tune-a-fish with all that going on.

RBob.

EDIT: noticed I had the wrong part #, correct # is SenSym #19C030PG4K (also changed above).

 

I get all the instrument stuff free from work, well no free, but they just don't notice its gone.