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Discussion Starter · #1 ·
I made a fuel injector tester/cleaner. I thought I would show you what I did. I mounted a T1 fuel rail and injectors to the top of the wooden frame. Then I wired them together with a modified fuel pump to turn on at the same time. I just have to apply 12 volts. The pump was from my Sunbird but I added a fitting on each end to run outside the tank. The 'fuel tank' is the small plastic container on top. It must be mounted above the fuel pump to allow the gas to drain down and prime the pump. I may have to remove the lower fuel line for a second to get the gas flowing, though. I can run fuel injector cleaner through the injectors. I can see the spray pattern as well to see if they are spraying well. I can snap in my T2 injectors as well. Under the injectors i will have some empty water bottles to catch the fuel. I did this because I'm too cheap to buy new injectors unless I really have to. Enjoy.



 

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very cool! now you've become a mad scientist!!
 

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it looks like you dont have anything physically holding the injectors in place. fuel pressure *will* push them out of the fuel rail if it gets very high.
 

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Thats cool, I was thinking of making one myself. One question, are you pulsing the injectors or run continous power to them ? I can really apreciate a person that builds his own stuff.:thumb:
 

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Discussion Starter · #5 ·
I do have metal clips holding them to the rail. I might still have an issue with leaks...we'll see. The o-rings are nice and tight, though. I decided to use the FPR from the stock T1 rail, so the pressure should top out at 55 psi. Plus, I am using the return fuel line to go back to 'tank', just like stock. I am not sure what the pump will provide for pressure yet. It is from a TBI car, so the pump may not make it to 55 psi. I won't know till I try. Should be testing it this weekend. I'll let you know.
 

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You may want to watch the amount of time you give the injectors full power, as our injectors don't like to have full battery voltage to them for long periods of time. Short bursts are proably ok, but I've split an injector housing from having full power sent to it for too long (Megasquirt was shorting injectors to ground without my knowing it :bash: )
 

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Discussion Starter · #7 ·
Thanks for bringing that up. I had heard of that from people trying to use normal injectors as cold start injectors for dumping in extra fuel at higher boost. I will keep an eye on that!
 

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yeah hence why 100% duty cycle is not recommended, and they get hot.

you need an AFPR to drop the pressure and note where they start to dribble, well I'm interested anyway

OH BTW I never noticed you were in MI, we'll have to meet up sometime
 

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it looks like you dont have anything physically holding the injectors in place. fuel pressure *will* push them out of the fuel rail if it gets very high.
Hell yes. Been there, done that. I solder-brazed some homemade NPT bungs onto a Neon fuel rail for use in my 16V conversion. I decided to pressure test it and I shot a Stratus injector across the room!!
 

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Thanks for bringing that up. I had heard of that from people trying to use normal injectors as cold start injectors for dumping in extra fuel at higher boost. I will keep an eye on that!
Not only due to the 100% duty cycle thing, but our injectors are low-impedance. Under normal operation, they have full power applied to them initially to open them, then the ECU switches power on and off rapidly to keep them open. So even if you only test for short spurts, they aren't being powered in the way they were designed to be. Again, it probably won't kill things unless it's done too much.

Megasquirt's ms2/extra code has a built in injector test mode, which can handle low impedance injectors. Dunno if it's worth the couple hundred dollars to get a MS, but if you can find one cheap, might be helpful.
 

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Discussion Starter · #12 ·
Speeduphoria - Good thought on the AFPR. I could probably just build one of those, too. I have instructions from another site. I would love to see your car. I haven't seen a 16v conversion yet. What part of MI do you live in? I'm 30 minutes from Grand Rapids.
Risen - I would love to have a Megasquirt to mess around with. The wiring and assembly looks pretty intense. I'm not as computer literate as I would like to be, so the software would probably be a pain to figure out, as well. I haven't seen really great instuctions on how to use it, so that worries me. I guess I'm just a little leary because I have a lot of questions about it and not a lot of answers. I spent a couple days on the megasquirt forum about 18 months ago and didn't learn as much as I had hoped.
As far as this project goes, I'm just going to keep it simple. I really didn't need to build the tester, but I was curious and I had some extra parts laying around (bad combination). If there was drinking involved I probably would have won a Darwin award. Actually, I better keep a fire extinguisher handy, just in case.
Thanks.
 

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I meant the MS more to run your tests with. I've done one MS install which was put into an 85 glht and integrated into the factory harness. Its definitely not for the weak of stomach, but they do work well when setup properly. After spending that much time on an install, it really drives me nuts to see all the ghetto MS installs out there.
 

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Discussion Starter · #15 ·
Good Thought, tkelly27! I originally thought of just catching the fuel spray in a plastic water pop bottle under each injector. I thought I would just visually watch the spray cones for inconsistencies to see if the injectors were spraying well. If I accurately measure the amount of fuel out each injector, I should be able to determine how much each flows and compare. That way I can determine which ones need more cleaning.

I realize that the actually flow rate will be different than what I measure since I'm not pulsing the injectors.
 

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Discussion Starter · #16 ·
I know it's been awhile since my last update. I just recently tried it out. I was waiting to get some fresh gas. I have been using old gas in my mower since I have a tank full in my daytona. The test worked very well. The injectors kept cool but the alligator clips got a little warm. There is a lot of juice flowing through those wires! My switch pooped out so I just touched one of the wires to the terminals to pulse it on and off. The stream from the injectors is very fine. I thought it would fan out more. Maybe it should fan out more. I will have to look into that. I will try some injector cleaner in the future to clean them up real good. I didn't bother looking at flow rates right now. Too busy with other things.


 

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thats a cool idea.
Good for those with lots of cars.
I cheat and just look at the fp and take the injectors out with the harness and wiring and look how they pulse and eye ball to see if they look like they are all pulsing the same
Not as accurate but it works and hasn't failed me yet
 

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Discussion Starter · #18 ·
I looked at some pictures on the internet on spray patterns. A standard "pencil stream" does not fan out much at all, maybe 10 deg. Mine don't seem to fan out at all. Hmmm.
 

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instead of running gas through those use seafoam- it was originally designed to remove varnish in outboard motors. probably one of the best fuel system cleaners on the market. probably the best would be dichloromerthane- carb cleaner, but it evaporates way too fast, so it would take a lot to properly clean injectors. the seafoam would rock though.

you could use a pair of hevy duty electronic turn signla flashers to turn the injectors on and off. just use 2 of em and set them up so it kicks voltage from one injector to the other. the heavy duty electronic ones are made for trucks pulling trailers, and the lights are around 2-5 ohms, similar current draw to the injectors. plus the on off motion would help work any crud out of them. would cost all of 20 bucks and look damn cool when its running. now you just need to use clear glass beer bottles for the catches for each injector and a jack daniels bottle for the cleaner tank.
 

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Looks like the fuel pressure is too low.

You need to current limit the drive to the injectors. The MS circuit does it with the LM1949 part. The other way is to place 6 ohm 10W resistor in series with each injector or 1.5 Ohm 50W in series with the group of 4 injectors. The "on" voltage should be about 5V at the injector.

The turn signal flasher idea seems good. It may limit the current too. The "on" period is however very long compared to typical injector times. Perhaps a standard duty will do better, however the flasher life may be limited.
 
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