3500 (LX9) swap into a Fiero

[IsaacHayes]

Yeah, you'll need larger. Not sure exactly what would be best, but 19#i s probably too small. Anyone recall what 3500 stock ones are?

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[flimbob]

If I have to get different fuel injectors, I may look into the adjustable FPR/returnless mod Joseph Upson spoke of.

[Joseph Upson]

Stock 3500 injectors are about 24 lb/hr from what I can remember the first time I looked them up. That's correct, at 380 Kpa (55 psi). Not sure if flex fuel injectors are the same in the event that was offered with the Uplander on the 3500. It's possible there's enough reserve so that a change in the stock code is all that was necessary at the factory to make up for the difference in that case although I believe they are still different in that circumstance.

[IsaacHayes]

Why go to returnless? Swapping injectors are easy. :P

[flimbob]

I have a 16lb set which is in my 2.8L, I have a 19lb set that came with the 3100 fuel rail. I also have a set that came with the 3500. I am under severe cost constraints and can not afford to purchase a set of 24lb injectors to use with the 3100 fuel rail. I need a solution that is around $50. I believe I can get a suitable adjustable FPR for around that price. Joseph Upson has already proven a modified returnless system can be done. I have also talked with a very knowledgable person from the 3800SC camp that has converted returnless systems on a regular basis with no drawbacks whatsoever. It also allows me to use the stock components from the 3500 that I already have in my possession.

[Joseph Upson]

I have a 16lb set which is in my 2.8L, I have a 19lb set that came with the 3100 fuel rail. I also have a set that came with the 3500. I am under severe cost constraints and can not afford to purchase a set of 24lb injectors to use with the 3100 fuel rail. I need a solution that is around $50. I believe I can get a suitable adjustable FPR for around that price. Joseph Upton has already proven a modified returnless system can be done. I have also talked with a very knowledgable person from the 3800SC camp that has converted returnless systems on a regular basis with no drawbacks whatsoever. It also allows me to use the stock components from the 3500 that I already have in my possession.

Avoiding any changes that move backwards in technology is a good thing whenever possible. The newer the parts the better. The adjustable regulator is also an attribute and having the ability to attach an inexpensive pressure gauge to it is another plus if ever you have a starting problem and have to diagnose. It's not a complicated accomodation at all, you're basically attaching lines to the regulator instead of the rail and running one line instead of two to the engine.

[IsaacHayes]

If you got it figured out and the parts aren't that expensive go for it. Used 24# from a DOHC or something do show up every now and then for sale though.

[Joseph Upson]

If you got it figured out and the parts aren't that expensive go for it. Used 24# from a DOHC or something do show up every now and then for sale though.

The problem with DOHC injectors is that the spray pattern is specific for the DOHC valve design with a wider spray pattern instead of conical which is used on single intake valve ports. They will work with no problem however the spray pattern will result in more fuel being sprayed towards the walls of the intake runner. I forgot the degree of the angle but the DOHC injector was designed so that fuel would be sprayed evenly at each intake valve in an oval shape to hit both valves rather than the narrower conical pattern aimed at a single valve.

[IsaacHayes]

Ah yeah, forgot about the dual spray pattern.

[flimbob]

Looks like there are several adjustable FPRs on EBay. Has anyone had any experience with any of these?

http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT

http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT

http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT

I also found that the head of my oil dipstick is broken. Does anyone know if the 3100 or 3400 dipsticks are compatable?