Hello....

Not sure which section to put this in, so here it is!

I'm thinking of building this:

http://www.bgsoflex.com/fitester.html

It will let you pulse the injectors for a number of repetitions for different amounts of time... you can measure the amount squirted out and calculate flow and so on. By running the fuel through backwards or forwards, you can also clean them.

Anyone know if I can buy a preprinted PCB for this? Is there another competing product cheaper/easier than building this myself?

Regards,
B

 

That's a pretty simple circuit. It'd probably be easier to build it on a protoboard than find a PCB for it. I know that there are online companies that'll do short-run PCBs for not a lot of $$. Bruce is pretty good about replying to emails too. You could ask him.

*edit*

Now that I looked at the project again it looks like he cleaned it up a bit and did a group buy a la megasquirt. Might want to do a search on the mega-squirt yahoo group.

 

keep in mind that this is only a "Electronic Fuel Injector Tester and Analyzer"
it does nothing to clean injectors.

matt

 

well the cool part with this thing is that you can figure out the lag time of the injectors....

To clean them you can just set it up to flow fuel and keep pumping gas or mineral spirits through them... I think that will work.

B

 

The following $20 item will likely do what you are looking for:

http://www.sunpro.com/cgi-bin/web_store.cgi?
page=cp7819.htm&cart_id=7404939_16892

There are a couple 555 timers inside that control test time and duty cycle. These timer values can be changed quite easily by swapping capacitors/resistors.

Given you were interested in fabbing up BG's setup, a few simple mods to this one might give you all the functionality you need.

HTH.

 

there is more to it than flowing fluid through them.
I have purchased and made all the equipment for
cleaning injectors, even building most of it myself i
am into it for over 500.00 cdn.
then there is knowing what type of cleaners are
needed , and what's needed to keep the injectors
from seizing shut.
the only reason i set up a low cost cleaning service
was to offer a low cost option for cleaning to fellow
rx7 owners.
I love diy and would offer to show every step and the
tools needed to start cleaning but know this
you have to spend a fair dollar on some equipment that
cant simply be made.
matt

 

Hmm an interesting item, but I'm really going to go all out and build this thing (or try anyhow!). I WILL post back here if I ever get it working right!

B

 

my nozzle tester not finished yet but each step has been tested and dose work.you can check current draw, voltegwith the use of a scope/current probe and flow with spray pattern

 

gambone, sent you a PM

B

 

my email sarav@quik.com yalk to me, key words Darlington Pair , Radeo Shack ,Transtronics/SK-302 kit it works for $60 and a trip to Pick A Part

 

An update on my efforts...

I purchased and assembled the SK-302 pulse generator. Because the output of that device only goes up to 10 volts and around 0.25 amps, I needed/wanted more juice to drive my injector.

So what I did is took a TIP120 transistor and wired the base to the output of the SK-302... then I hooked up the injector to +12 V and also to the collector of the TIP120. The emitter of the TIP120 is hooked to ground.

So what happens is the SK-302 sends out a pulse, and this grounds the injector, opening it. I have tested this out and it opens and closes the injector and seems to be doing the "right stuff". (I don't have an oscilloscope to verify this yet).

Next steps are to get the o-scope to measure exact pulsewidths and so on and also to hook up a fuel source to the injector so it actually sprays something.

If I ever get the whole rig working well, I'll be SURE to post a "how to"... don't worry!

Brian

 

One note, if you are looking lag timethat the pintel takes to move off it's seat to the open posistion you will need to test the nozzles on the car it's self, factore such as full cerunt/volteg that only the auto system its self can give.I did this last friday doring a tune up on some nameles car. I think that pic I sent you is realy hard to read, so the is a hand drawing in the works that will show this time factor and how to read it

 

more info, the pintil takes 1.4ms to have moved, 4.ms to full cerent draw, 2.ms at full curent, over all time 6.ms at idel on a 4.6 OHC Ford 96, just about all nozzles will be in this ball park. The only change there will be at higher RPM is the full cerent on time. If you are going to do one at a time that's OK, but what about flow? Doing all the same time each nozzle in to itx own test tube and then comepairing the valumes is the only of knowing if you have a matched set. As time goes on there is ware and thuse the flow rats between the nozzles change, rough sets in, this can be seen scoping the 2nd igntion and looking at the fireing line, this is a dead give away when some one mixes the connectors between the per and sen nozzles. One is realy lean and the other is rich.

 

well the REAL information I was looking for in building this thing was to answer the question "what is the lag time on a 1600 cc/min injector?"

According to the people that make the Datalogit, the stock 550 injector and stock 850 cc/min injectors are around 0.73 and 0.77 ms. The 1600 cc/min injector will be longer because it's a bigger injector. But how much? I wanted to be able to measure how long my injectors take to open so I know what to put in my PowerFC for "lag time".

Brian

 

Brian,

Clamp a knock sensor against the injector rail, and then using an oscilloscope watch the traces of both the electrical input to the injector, and the knock sensor output. You will see a blip on the knock sensor when the pintle opens, and measure opening time via the offset from injector 'on' signal. This value also changes with voltage, so an idea of opening time as a function of system voltage is helpful as well.

This method was detailed years back in an article in Performance Magazine, put out by John DeArmond.

 

renns,

Cool idea! I think I just might give that a whirl I understand the concept, but it's been a while since I've used an oscilloscope

Brian

 

Sorry to step on the knock idel but all it will give you is a signel that something had happened no real time frame. A cerunt clamp or probe PDI makes, it's a small indutive and made low amp 18ga or so wire. can find them on Ebay, Snap On Tools, Car Quest, NAPA ?, $149 and as soon as I get my home PC back on line I'll e mail a pic of what the scope pattern will look like and how to read it.My CD burner took a dump,so went and got a DVD/CD burner and screwed something up, cant dial out, HDT dosen't come on hafe the time wirerless key bord and big screen HDTY is the way to go.

 

If you mean "Performance Engineering" (how many John De Armonds are there anyway? ) would you happen to know if he's still producing magazines, or if there'd be any way to obtain back issues?

 

Yeah, PE Mag is what I meant... I have no idea how many issues were published, but I'm certainl it's long-since defunct. I've only seen the two issues covering the fuel injector test stand amongst other things. The fi tester article was scanned and kept on the diy-efi site, although that site has been down for a while.

John is quite a guy. I've run across his info in numerous places on the net, and it is invariably worth the read.

 

Yeah, I found out about him first on Dave Williams' site text archives (now at http://www.bacomatic.org/~dw ) and later I found more of his info at www.yarchive.net and basically JGD is one of the best "gurus" on the net. As he said one time when someone asked him to back up one of his statements with a citiation... "I *am* the citation, I did the experiments and testing"

 

Bumb I like to see this one keep on going, So any how I read some of thoes sit mon Dave William and didn't find any thing relateing to the subjuct at hand, Off toppick what is boost creep