Love it but very very confused

[elhigh]

Originally Posted by consaka

But it just wont DIE, without which the wife wont approve the funds..
Course I could just let her drive it more hmmm I got a personal junkyard with cars shes driven.. hmmm

Oh man, I'm with you there.

Try owning a 22R. I've loved it for a long time, but it's been around so long I'm almost starting to resent it. Hurry up and croak you little #$@@%. I could afford something modern.

[consaka]

Originally Posted by dcb

I'm pretty sure you have TBI peak and hold, we finally got some real world data on that in January and are still working on the solution.

http://ecomodder.com/forum/showthrea...sory-6863.html

Hmm I read a bunch of threads and followed all the links I found. I note a couple of things on the tables that I could find. No pictures of any TBI injectors and most of the ones mentioned were not TBI injectors at all. I say most because I am not familiar with the few geo GM vehicles that were listed. I know the minivans by GM used TBI setups because I have seen them in the junkyard. I can see Coyote knows what he is talking about though so I will assume my '93 suburban 350 is peak and hold.
So now id like to better understand what the problem mpguino has with the peak and hold setups. I mean it is still pulse width modulated right? I see from stuff coyote said that his system was WAY off doing crazy stuff like reading 18 gh at idle or something. However I read around 1 to 1.2 gh at idle hot. as much as 3.1 or so when cold.
So when is it likely to be accurate? when idling or when cruising or 50% throttle? etc. I noticed today that I used or got the exact same mpg when accelerating about 45 mph anywhere from 20% throttle to 100% throttle. It always reads about 14mpg under those conditions. but under 20% it can drop to 12. Im going to try the 22k resister and see what happens. I got two zener diodes though so I think its the lower harder to reach one right? I hope I dont blow anything up.. hehe

[consaka]

I did a little test the other day. Well for one I put in the 22k resister that was suggested. I have an openguage unit with the floppy disk style connecter. It does not have a USB port for program changes so if I need to modify it im not sure what to do.
Anyway what I did was watch the GH on a full throttle run up to 55 mph. It never exceeded 3.77. I then did a run up to the same RPM, basically redline, with no load an it said it was using 6.54 GH.
So far I think any accuracy I am getting is at low load because that is where I have it set for i.e. cruise speed.
My way of thinking is that under full load it should be using more fuel due to the fact that the map sensor should be sending full fuel due to no manifold vacuum. Any idea what this is and how to fix it?
I plan on throwing in the laptop with datamaster and graphing both injector functions. under the same conditions and see what happens there. I have an industrial grade scope but I dont really know how to use it.. Wish I could afford a pico scope as they look simple enough for a novice to learn to use.

[consaka]

I put one of my fancy oscilloscopes on it yesterday and it is and follows that same peak and hold pattern we have seen posted. the temptation to hack my computer box(ecm) and find that digital signal is almost overwhelming.
But to tell you the truth the signal seems very dirty on my rig and the voltage difference is nearly impossible to see.
Im going to first look at some way of monitoring the current flow, then failing that, go back to trying to make some sort of flow meter.

[consaka]

Well my cute little opensource mpguino died the other day. The wife came back and it said zero like always only the 0 on the display had a little line through the upper left corner of it. I went ahead and unplugged it for a while and plugged it back in and there is nothing. totally blank screen.
Oh well it never worked right with my peak and hold injectors so I guess it was money down the drain. make a good paperweight though. Too bad too as I had an electronics engineer that was going to help try to solve the peak and hold problem.

[dcb]

I can reflash it if you send it back via S.A.S.E. (PM), but really I need someone with peak and hold to do some experimenting. I've got a few optos and can send it back with an experiment if you are up for it. Do you think you could measure the voltage drop across the injector at peak and at hold?

[consaka]

Hmm we could probably do that. I need to do some tests on it first to make sure I dont have a ground problem and Id be willing to try and help with your tests if you can detail out how they should go. I am not sure how exactly to measure the voltage drop at those various times as you suggest. I might need a better scope. Like my laptop sound card but then Id need a proper probe setup which Im not sure how to make.
Sounds like you might need a scope reading across the injector while its running?
I still think sending a wee bit of current through when the ecm grounds it should be enough to trigger an transister through the various events. just not sure how to try it without burning out the ECM hehe.