I've been searching for some injectors for my new 3400 motor. A buddy of mine has a set of 22 lb. fuel injectors from a 1993 Camaro Z28 and I was wondering if these are the right ohm for our computer. Also, would 22lbs be good for this setup?? I plan to run about 10-12psi of boost. Its a 2000 3400 block, iron heads, ported intakes, etc.

Also, anyone know if there would be a way to make the 3400 injectors work with our fuel rail? I haven't sized them up yet, and the connectors are different, but if they fit physically, perhaps the 3400 injector harness could be spliced into the fiero plug. I think the Z28 injectors would be better regardless.

Thanks agian,
John.

injectors are pretty generic in physical size & connectors. also, the low ohm injectors are rare. basicly, if it came from a passenger car, the physical size, connector & ohm requirements will be fine. Flow rate at 40 PSI is the only issue, and 22# should be fine for you are doing.

I'll have to take some pics of the 3400 injectors, they're a little different.

Seems the Z28 should be fine though...
Thanks!

You can take an ohm meter and measure the resistance of the injector coils. Just connect between the two terminals. Chances are they are okay, but if they're not it can burn out the driver transistors (actually chips) in the ECM. They should read around 14-16 ohms. MOST of the low resistance injectors I have ever seen were from imports, or were very high flow (32+ lb) units.

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Raydar
88 3.4 coupe.

Coming soon...
88 Formula, presently under the knife.

Injector sizing is a pretty complicated issue. This all depends on how much boost you are going to push and how much power you expect to make. For instance, the N/A 3800 Series II comes with 22lb injectors which will support 205 hp. Obviously, you can turn up the fuel pressure or have a custom chip made to allow them to support more power but there is a limit. There is only so much fuel pressure injectors can operate under and there is only so much time the ECM can hold them open. Honestly, if you plan on running any more than 205hp I would look for bigger injectors. The Series I 3800 SC and 3.8L turbo GN's came with 28 lb/hr's stock and finding a used set for sale is as easy as going to www.turbobuick.com as this tends to be one of the first upgrades made to one of those cars. Like I said, I think you are pushing your luck with 22lb/hr units.

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power corrupts. absolute power corrupts absolutely.

Custom GM Chip Burning | Fiero Engine Conversions | Turbocharging | dtcc.cz28.com

They seem a little small, and I only base this on the stock size injectors on a 87-88 Thundirbird Turbo Coupe.
2.3 liter factory limited to 15 psi came with 36 lb injectors. These were low impedence.

Gene

Anyone know of a car I can get a set of stock injectors that will work well for this application??

86-87 Buick Grand National or 92-95 3800 Series I Supercharged both had high impedence 28 lb injectors. Like I said, check the classifieds section of the www.turbobuick.com board, you should be able to find a good used set for about $100 or less. The will work in your engine but you will need a custom chip of course.

I've checked through LaGrua's site http://www.turbochargerpower.com/turbo.htm
I don't see any mention of different injectors or size of injectors for any engine sizes listed including 3.4L
Any recommendations from Dennis?

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3.4L S/C 87 GT www.fierosound.com
2002/2003 World of Wheels Winner &
Multiple IASCA Stereo Award Winner

[This message has been edited by fierosound (edited 01-13-2004).]

I plan on using a set of 3800SC injectors on mine and adjusting the injector pulse width to compensate as well. I've heard that Mustang 5.0 injectors will work also, but don't know for sure.

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85GT Turbo 3.4TDC/5-speed in progress
http://www.thestewartconnection.com/fiero/fiero.html

[This message has been edited by GT (edited 01-13-2004).]

Mustang injectors are 19lbs, and I can see where they would be good in a 3400 N/A swap. Don't think they weould be as good in turbo though.

quote Originally posted by Jncomutt: "Ford Motorsports 24 lb/hr fuel injectors are used and both the electrical specs (14 ohm resistance) and mechanical specs are compatible with both the Fiero ECM and the fuel rail"

OOPS I guess I missed it when I looked...

[This message has been edited by fierosound (edited 01-14-2004).]

If you want new injectors, or low mile "take-outs" with a warranty, check here... http://www.fiveomotorsport.com/Injector_Sets.asp
Prices are as reasonable as I have found. I paid ~$170 for eight, including shipping. That was a year ago. They've gone up a bit.

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Raydar
88 3.4 coupe.

Coming soon...
88 Formula, presently under the knife.

Hey darth, there is a guy there selling 28# from a late 80s turbo regal, 3.8. Those should do right?

I've used the blue top FMS 24# injectors and they work fine.

I have two extra if anyone needs a pair.

quote Originally posted by Jncomutt: From his site... "Ford Motorsports 24 lb/hr fuel injectors are used and both the electrical specs (14 ohm resistance) and mechanical specs are compatible with both the Fiero ECM and the fuel rail"

Howard, on a 3.4 turbo?

No.

quote Originally posted by Jncomutt: Howard, on a 3.4 turbo?

Who burned your chip, and did you have any problems at idle, or running it rich N/A?

quote Originally posted by Jncomutt: Hey darth, there is a guy there selling 28# from a late 80s turbo regal, 3.8. Those should do right?

yes, those are the ones I am talking about. just keep in mind that you will have to get a chip done to compensate for them.

jncomutt, I built a calculator when I was planning my 3.4 turbo. Darth is correct as @ 12lbs boost and 7K rpm you need 22.8lb/hr which is over the specs of your injectors. Ideally, leave ~ 20% margin as injector control is more precise when you aren't touching the fringes of the design in this case duty cycle. So doing a little algebra... yada yada, carry the one and voila it looks like 28lb/hr will work for you. Ah Darth is right again. He knows his stuff doesn't he. My approach is making several assumptions which is limiting max RPM under full load to 7K (in this example) and that you are trying to build maximum power/volume @ 12lbs of boost (which was your upper limit). If you want to exceed that boost figure, you will need to up the 28lb injectors. Also, the flow rates I used are at 40 psi (which is typical). I did that because flow rates aren't linearly proportional with pressure and the flow curve varies from one manufacturer to another. Hence I opted to use their specs for flow at their specified pressure. Also, the max power / volume assumes your engine won't be wheezing in the intake or exhaust side but that assumption will only help your margin. Have fun and good luck w/ your project! Keep us posted.

Awesome, Thanks 87... I don't think I'll rev to 7k, more like 6 to 6.5 if it likes it up there. I don't know how well the turbo is sized either, its mostly just adjust as I go. Hopefully it will put out good volume at 12psi for the 3.4, but we'll see. I can always sell it for more than I paid and get something more adaquate.

Any reccomendations for a fuel pump while we're here? I have a new 2.8 pump in the car now, which I plan to run for the mean time. I haven't heard of anyone having problems in any setup with the stock pump, most just change it for peace of mind. Like I said, I'll put it together, and if it fails to keep me satisfied, it can always be swapped for a vette or something later on. Just figuring I might as well add it to my list now than never.. (funny how long that list keeps getting)

Do you have any info/pics on your car??

Thanks again!