DIY fuel injector pulse tool

[BigSki]

I built this a few years ago following a schematic I found on Dinofab.com The newest site that has the info for this is: https://www.google.com/url?sa=t&rct=...D4hvu7LEyD5JWw

Commercial units are available that do the same thing and more, I didn't have (and still don't) the budget for one. This was the perfect answer. It took me a few tries to get it right, the breadboard version worked perfectly, the PC board gave me a few headaches but in the end, it worked great.

Fast forward to today. I dig this thing out and attempt to cycle the injectors for the WJ so that I can douche them out before re-assembling the fuel rail. I somehow managed to hook the wrong end to the power supply and of course, the tester didn't work. I take it home where I fiddled with it for about 6 hours, finding and replacing a fried Zener diode but still not getting any voltage out to the injector. I finally found the issue- there was a small piece of the copper trace that had melted away from my earlier stupidity. I made a simple bridge from a bad LED lead and it worked!

Tomorrow I'll get a can of carburetor cleaner, submerge each injector and cycle it for a few minutes to help clean them out.

Here are 2 small testers that I made when I first built the injector tester. One is a tester for the 555 chip. If the chip is good, the LED will blink until you pull the 9V away. The other one tests the MOSFET transistor. If you have a good MOSFET, the LED will light up when the button is pushed.

[BigSki]

Action pic.

[C*H*U*D]

Originally Posted by BigSki

Action pic.

Pictures have no action...where's the video?

I could have used this a few weeks ago when I was putting the 4Runner back together. I'll have to make one for future use.

[allanon1965]

nice little tool, but I bought one from allsun, the EM276 for 45 bucks...new... I used to have an OTC one that was the same thing..it was about 100.00... but I figured for 45 bucks it wasnt worth going thru the time and hassle to build one...plus it has the option to have continuous,short,medium or long pulses...

[C*H*U*D]

Originally Posted by allanon1965

...plus it has the option to have continuous,short,medium or long pulses...

Hrmm...I wonder if it would be poossible to use an Arduino for this instead of the 555's. I know it would easier and probably cheaper to buy the unit you have, but I like projects like this.

When I can find the time

[BigSki]

The one that I built does 1 second, 5 second or a continuous pulse. Dino Fab explains how to increase the length of the pulses while building the circuit.

I agree that it's always easier to just something that's readily available, I just got a lot of satisfaction out of building my own. It's been so long since I did anything actively with electronics, I'm in dark as to what's new. The Arduino that C*H*U*D mentions has caught my interest, but when I look at the programming needed to make them do what you want them to do, I just stopped. I have no desire to learn a programming language.

[C*H*U*D]

Originally Posted by BigSki

The Arduino that C*H*U*D mentions has caught my interest, but when I look at the programming needed to make them do what you want them to do, I just stopped. I have no desire to learn a programming language.

They really aren't that difficult once you start playing with them. And they're so cheap, it's not that expensive of a hobby. Plus, there's a lot of things you can make them do for our hobby. You should grab one and power it up

[allanon1965]

Originally Posted by C*H*U*D

Hrmm...I wonder if it would be poossible to use an Arduino for this instead of the 555's. I know it would easier and probably cheaper to buy the unit you have, but I like projects like this.

When I can find the time

that was my problem, I used to build alot of my own testers for work, ford TFI module testers, ford PIP testers, gm HEI module testers, and such, but I had very little spare time to build them and when they started getting inexpensive, I got lazy lol

[fyrstormer]

What is this for? Is it for anything related to RC, or is it actually for testing fuel injectors?

[CM9000]

fuel injectors. electronic only though

I wish I had made one 3 yrs ago... but I have a chance to make one now!

itl be a good use for my efi Cleveland build.

[fyrstormer]

Well yeah, mechanical fuel injectors are an entirely different beast. Does anything even use mechanical fuel injectors anymore?

[BigSki]

Originally Posted by fyrstormer

What is this for? Is it for anything related to RC, or is it actually for testing fuel injectors?

the 555 chip tester could make a nice strobe light for RC use.

[CM9000]

Originally Posted by fyrstormer

Well yeah, mechanical fuel injectors are an entirely different beast. Does anything even use mechanical fuel injectors anymore?

military vehicles to not include anything with a 6.2 or 6.5 gm

ie. series 8v 92 and all the others including the 6v 92

and any old garbage cat.

I was simply making a joke of it.