HAILERS

Does anyone disagree, that if an injector is hooked up to a rail, and a measured container is put under it,and then a 12v source and ground is put on the injector, why I should or should not expect after one minute, to get the volume that the injector is rated at????? Like a 460cc injector, I would expect after one minute to get 460cc of fluid. Is there a basic flaw with what seems to be an obvious result of 460cc, plus or minus some small amount.??????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????

SpeedRacer

Your reasoning, makes sense, but I think you'd fry the injector putting 12v on it for 1 minute. Is there a way to manually open the injector fully and force fluid through it?

Samps

Making the injector run at max duty cycle for a whole minute would most likely lock it up, I think.

Samps

Hey HAILERS! here is a thread where you and Irv's dad seem to of already discussed this.

Was this just a test to see who would search and who would just make stuff up?




https://www.rx7club.com/forum/showth...check+injector

HAILERS

I have a spare secondary rail. I put two injectors in it. I zip tied them to the rail. I made a harness of two wires with an injector plug on one end and two alligator clips on the other. One the power wire I put a 10 ohm resistor in line. I took the pressure and return line off the pipes they hook to on the engine. From there I put a union in each hose and connected three feet of fuel hose to each. The other end connects to the secondary fuel rail mentioned. I jumpered the fuel connector on the r/h strut tower. Now this fuel rail is sitting on the front air snorkel. I put a container under the injector to be tested(measured container in ml. I put the alligator clip for the power wire on the battery positive. Then when the second hand on the clock reaches where ever, I put the alligator clip for the ground wire on the battery negative post. I wait for one minute, then measure the volume. Also look at the spray pattern.
About burning the injector up. I don't think so. I have a meter connected to my primary and another meter connected to my secondary injectors on my other car. I watch day after day the voltage on the primary injector vary from 11.5 volts down to 4v hour after hour while driving. So if it has a load hour after hour, then the darn thing should be able to survive me putting 12v on for several minutes. Could be wrong though. If someone is sure I'm wrong and has a good theory, I'm open to the thoughts.
Oh, about watching the volts on the pri and sec injectors: the secondary injector is one lazy injector. Only works maybe 20 percent of the time due to the loads on the engine. Even at a steady 80mph on level ground it sits on its bottom and does nadda. Only under load above 3800 does it wake up and do a little work.

Samps

In that case, your theory would seem to make sense. You might loose a lil acuracy in your timing method, maybe you should due 5 or 6 runs then avarage your results. You also might loose a lil fuel due to atomization and the fuel being lost into the atmosphere. If I were you, I would at least do this test using fuel injector cleaner, so in the end, if nothing else, at least you cleaned you injectors preaty good.

- or -

Fill a container with the 460cc of fluid and time how long it takes the injector to empty the container. This way the fule loss and inacuracy might be avoided.

HAILERS

SAMPS......Nah. Not bright enough to think up a scheme to test who knows how to use the SEARCH ENGINE. Anyway, I left out the part where I drained out all the fuel except for a bit less than a gallon. Then put in eight bottles of fuel injection cleaner. This project is just a little different than the one mentioned earlier. On that one I use the secondary fuel rail on the engine. This time I use a spare rail and ran the pressure and return line to it. It was a bit combursome doing it the other way. So anyway I've got ten spare injectors and I'm amusing myself watching the different spray patterns. One thing that seems to make the pattern look different is the pintle and how far recessed the *plunger* is from the pintles hole. Right now I'm low teching it using a sports drinking bottle that is graduated in ml. Oh, yeah. One thing I did different this time is use a 10ohm resistor in line, just in case. But I have had no problem with the injectors I've done in the past without one. Right now I'm pissed because after one full minute, no injector will read exactly 460 or 550. P.S. I do each one three times and some four. By do each one, I mean make them **** in the container and measure the amount each time. By the way folks, when you put that injector fluid in your take. where did you think that crud and varnish in the tank itself was going. Filter change time a coming up. Hey, anybody got a lite for my cigarette while I do this???????

Keith

Hey HAILERS,

A couple of quick comments. Factory specs on these injectors are 444-472/min on NA, 532-568/min on TII. As you can see, there is some tolerance here. However, there is a missing spec. here. That spec is pressure. The standard pressure for injector flow rate testing is 43 PSI. What that means is that a 550cc injector will flow 589cc at 50 psi (correction factor Sqrt of (new pressure/old pressure) ). Since our pressure regulators run at, let's say, 39psi, a 550cc injector would flow 524cc. This of course assumes the pressure remains rock steady. If it varies, so will the volume put out by the injector. You mentioned in an earlier post that pressure rises with boost in our cars. Well, that is an easy way to increase volume for a given duty cycle, a common practice in modern boosted vehicles (not just ours). So, to complete your test setup, you need to supply air pressure to the fuel pressure regulator to hold 43 psi. Then you should see 550cc out of a 550cc injector, within the above mentioned tolerances. Any questions???

Irv, Keith's dad

HAILERS

I don't know how to put it except to say, Irv, YOU'RE ONE SMARTY. You hit the nail on the head. I was getting only 500 cc out of a 550 injector. I'll just hook up my Mittyvac and see what the results are then. I'm getting consistent results out of my little league experiment in the way of volume, just coming up short on the volume end. To my credit, I did look in the factory manual and they give a range of volume for opening the injectors for 15 seconds, and I fall in the ballpark. I still want to see 550, well......because, thats why.