305's are different
 

Well, they're different enough that I stopped to ask y'all.

You'll notice that the blue(1.6) and tan/brown/orange(1.8) are different than the 305's(green). The body is essentially the same shape until you get past the second hump, and the nozzle itself is different (bare metal) with much larger openings, and 4 instead of 1. The stockers also have that black plastic ring around the base.

Are these good to go?

Your 305s are supposed to have that plastic cap on the bottom over the pintle. The pintle is the needle thing on the bottom that squirts and the cap is called the pintle cap. The ring is an insulator, and that goes on the pintle cap. You're supposed to have that too. You could try to pull the caps off the blues and put them on the 305s, but I would be leary because the pintles may be damaged from not being covered. A 10mm socket is about perfect to push the caps on if you want to try, but I wouldn't. Be safe and send them to be checked and cleaned.

Sonofabitch!!!
Ben, I believe you, but can somebody else confirm that?

I bought these from a guy here on the forum a month or two ago (one of the regulars), but have since erased my PM's and don't know who it was. I've also thrown out the box. I can't believe he would send me something with key parts missing.

Can I buy just the pintles and insulators from somewhere? They came packaged very well and have been sitting in bubble wrap ever since I first looked at them. I'm not worried about them working but also don't want to spend the $100 to send them somewhere for a tune when I only paid $50 for them.

Now hang on a second. I just google searched for "fuel injector pintle" and this was the first thing it popped http://www.sdsefi.com/injectors.htm This page shows various types of injector and some of them don't have a plastic end cap or insulator... so, maybe the 305's aren't supposed to have them. Can anybody confirm?

I bought a set of 550s off an RX7 one of them didn't have the pintle cap on it. I sent them off to cleaninjectors.com. $65 total later I had a set of cleaned injectors with all new pintle caps, top screens, orings and top grommets around the base. You need pintle caps far as I know.

oh man! I just got a set of 312cc maroon tops and they don't have a plastic cap. They have the insulators but no cap. Is everyone sure that they are supposed to have them? I was planing to install them tonight but I don't want to pull the old ones out just to put them back.

Well, if the stock miata injectors have them, and most swappable injectors for the miata have them then for our motor I would assume that you need them. It appears that they are not needed on all injectors, but most of them do require a pintle cap in good shape. I don't know much about the 312's so you might want to call a shop like cleaninjectors.com and ask, they're real friendly so i would.

I pulled a cap off of an injector to show you that without the cap, it looks exactly like yours. My dig cam is dead, so as soon as its charged, I'll post a pic. The pintle is the needle at the end of the injector. So if you wanted to see the pintle, you've got to remove the protective pintle cap.

The cap and insulators are both removable and replaced when the injector is serviced. Like I posted before, if you're feeling froggy, *carefully* pull the caps off your blues and push them on the 305s. However, especially since they came to you without the caps, I'd send the injectors to be tested first. We monitor a "combined" a/f with our wb in the dp. Meaning 3 cyls running slightly rich + 1 cyl running moderately lean = acceptable combined a/f but could end up leaving a lot of performance on the table (timing) or even cause major failure.

sam pull of the insulators from your injectors and swap them over

Hmm.. I put my pictures up, but after looking at your 305s again, they indeed have a differently shaped body than the mazda injectors. I'm retracting my advise about switching the caps over; they need different (shorter) caps than mazda injectors. Some of the RC injectors use a small cap like that yours.

Maybe I'm completely off base. After looking at pics, maybe the short tip toyota injectors don't get caps... Looks like the short tip RCs don't get caps.

Both Brad and my own 305s dont have the caps.


My 295cc injectors look the same:

http://www.rev2red.com/images/cars/injector.jpg

So you use yours with out caps or it is just not supposed to have them?

It's my newly formed opinion that the short tip Toyota injectors don't get caps.

I also want to point out that the short tip injectors won't go as deep into the motor, but I don't know if that would make a real world difference in atomizing fuel into the charge.

doesn't bother me none.

My Toyota injectors don't haev plastic caps with.

Nor mine - they work lovely, especially with my new ECU :)

I just went out and tried to put both the 1.6 and 1.8 caps on the 305's... no joy. They're too small. The insulators from the stockers will go on the 305's without the caps, but its clearly a tighter fit... really gotta force them on. So, based on the above posts... I'm just gonna go for it right now. I'll call one of the injector rebuild places and ask them for pro help if something doesn't seem right. I've gotta take a friend to the Airport now, so be back with results in an hour or two.

Thanks for the advice... one more link in the information chain that everybody can benefit from.

you dont want to use the caps on from the miata injectors....just look at the outlets...

Yup, the insulators go on the 305's with a little effort just fine without the caps. It's too late right now to start it and try and tune... neighbors loved my last 2am rev-session when I went catless.
So, tomorrow morning sometime I'll fire it up, take a couple turns out of the MAF and go for a drive (a little drive-and-tune). Then come back home, swap in the RX7 MAF, and repeat... I'll have good feedback for y'all by noon hopefully.

Brain, you said your 310's would idle fine with 7 clicks looser on the stocker... would you just repeat your stock and RX7 click-count for me.

See ya tomorrow.

RX7 and OEM will idle at any tension...the fuel mixture won't be ideal.

The RX7 had the best idle mixture at like 3-5 clicks.

OEM; I left the tension the same but backed the idle mixture screw back one full turn. Gotta drill it out...looks just like the screw on the TB.