Fuel injector upgrade problem

[DjLiquid]

I swear that the CA gods have it in for me. I must have done something wrong =/. Every time I fix one problem, another two rear their ugly head. Here is my problem now.

Im upgrading from the stock injector to 550cc injectors I got from an RX-7. The only difference between my old injectors and these new ones are the diameter of the shaft right before the fuel dispencer. It's about 1.5-2mm larger. This little number means two things. They will not fit inside the intake unless I do one of two things. Take off the heat shield protecting the shaft or bore out the injector hole. I tested it without the heat shield and it's almost a perfect fit. I would hate to run them and have something burn out but considering the shield are made of a plastic compound do they even do anything? On the other side of things, I would really hate to bore out the injector hole which means about 5 times the amount of work I would have to do and then screw it up (seeing how things are going so far).

What would you guys do?

[boost_boy]

Are these the purplish-redish colored injectors? If they are they should fit. I used RX-7 injectors once and they dropped right in. The only thing I had to do was change my nissan connectors for the RX-7 ones.

Dee

[DjLiquid]

yeah, something like that but the injectors dont fit in the holes on the plenum with their heatshields on. would it be okay to use them without the shields?

[mbmbmb23]

yeah, something like that but the injectors dont fit in the holes on the plenum with their heatshields on. would it be okay to use them without the shields?

So you're saying the pintle caps dont fit into the holes? Why not try and swap the ones off the OEM injectors on there?

-m

[DjLiquid]

The ones off the oem injectors are about 1mm too small and are very britle and will crack upon removal.

[DjLiquid]

*bump*

Im kinda stuck without a car atm with this problem. Would you recommend I:

1. bore out the intake.

OR

2. run the injectors without the shields.

Ive gotta get this moving.

Thanks!

[boost_boy]

Show me a pictur of these injectors you speak of because I didn't have any problems installing my RX-7 injectors back in the day. What generation of RX-7s injectors are you using? I'm asuming the TurboII units, correct?

Dee

[DjLiquid]

according to the guys on here (http://www.rx7club.com/showthread.php?p=6757270) i have these:

1988 13B Turbo, high square offset, 550cc, purple, 195500-1370 (part number)

[DjLiquid]

infact, these are them exactly:http://www.stealth316.com/2-fi_pics.htm

Denso 550cc injectors

[float_6969]

Something is screwy here. They should work. LOTS of guys have used them w/o the problems you're having.

If you remove the cap, it probably won't seal and you'll have a boost leak. do you have the wrong lower insulator/rubber seat?

[anumeric]

according to the guys on here (http://www.rx7club.com/showthread.php?p=6757270) i have these:

1988 13B Turbo, high square offset, 550cc, purple, 195500-1370 (part number)

I have always thought that the stock purple top ones from a 88' turbo II were high impedance. Have you check the injector with a ohmmeter to make sure? On the link you posted, it says the Denso replacement 550's used purple tops for both their low and high impedance injectors. Wouldn't hurt to check.

Wei

[nismoplsr]

That is a weird problem... I dont have much help for you concerning that.

About the impedance though. Weather they are high or low is not a huge deal. If they are high then you just have to bypass the resistor pack. But perhaps the color is the only thing the 2 have in common, being shape and impedance being different.

Still would surprise me if the housings where different shapes from the same manufacturer. Specially when they are same flow rates.

[DjLiquid]

i am 100% sure they are low impendance.. i used an ohm meter when i bought them to make sure.

[ca18det240hatch]

rotaryresurrection.com

under injector guide itll tell you what one is what by the appearance and the number on the side.

GL

[DjLiquid]

The problem not lies in which injector I have, since I knew what they were when I bought them over a year ago. The problem is that the shaft of the injector that goes into the plenum is too wide for the hole itself. If i take off the heat shield on the injector, it will fit but im afraid it'll burn it out if it gets too hot:

My delema is:

run it like this:

or like



I hope I dont come off sounding like a douche but people dont seem to see the problem im having. The injector is the one I need. It just doesnt fit. I can make it fit but should I bore the plenum or run the injector without the shield.

Incase anyone wants to read up on fuel injectors just for the fun of it, I just ran into this site:

http://sdsefi.com/injectors.htm

[mikesim]

you bought high impedance injectors dude.

1988 RX-7 195500-1370 Saturated 550cc Purple Top

Saturated means HIGH impedance.

What you needed are the Tan tops. I've seen and held tan tops, but the guy was asking for too much.

1986-87 RX-7 195500-1370 Peak and Hold 550cc Tan Top

here's the site i use for determining RX-7 injectors:

http://www.robietherobot.com/s...e.htm

[DjLiquid]

you bought high impedance injectors dude.

1988 RX-7 195500-1370 Saturated 550cc Purple Top

Saturated means HIGH impedance.

What you needed are the Tan tops. I've seen and held tan tops, but the guy was asking for too much.

1986-87 RX-7 195500-1370 Peak and Hold 550cc Tan Top

here's the site i use for determining RX-7 injectors:

http://www.robietherobot.com/s...e.htm

lol.. i have the tan ones

[DjLiquid]

you bought high impedance injectors dude.

1988 RX-7 195500-1370 Saturated 550cc Purple Top

Saturated means HIGH impedance.

What you needed are the Tan tops. I've seen and held tan tops, but the guy was asking for too much.

1986-87 RX-7 195500-1370 Peak and Hold 550cc Tan Top

here's the site i use for determining RX-7 injectors:

http://www.robietherobot.com/s...e.htm

ok.. ill stop confusing everyone right now. I have the tan top ones. If i said that i owned purple ones, im sorry. the ones I have are tan. im 100% sure. They are low impendance. I checked with an ohm meter. I will also post pics later

[DjLiquid]

here's a picture of my injectors taken on my desk