RX-7 550cc Injector Clarification

[SideWinderGX]

Here be a conglomeration of all the searching I've done thus far, that has not resulted in a definite answer:

The low-impedence 1986 - 1987.5 FC turbo fuel injectors are *purple* brand new.
When faded, they look gray / tan.

The high-impedence 1987.5 - 1988 FC turbo fuel injectors are *red* brand new.
When faded, they look pink.

Both sets use the rectangular "Bosch-type" plug, but the keys are offset due to the difference impedences.

The low-impedence, early year ones are center keyed.
The high-impedence, later year ones are offset to the side.

Stock 440cc 7MGTE injectors are low impedence.

I've seen multiple threads stating that the purple topped, low impedence 550cc injectors from 89-91 turbo RX-7s are a 100% drop in injector...no new clips, no fiddling with injector resistor packs, no nuffin'!

However I've seen a few threads saying you need clips, or the high impedence ones clip straight into the harness...but you need to bypass the injector resistor.




Originally I wanted information just on the drop-in injector, but now I'm curious...what would you have to do to install the low AND high impedence injectors into the 7MGTE?

I'll continue to search and compile more links/info to throw in here once the answer has been found, just for future reference.


edit: Heard about a SOGI 550cc injector 'compatability' page...can't find it lol

Second edit: found it, http://www.supras.com/06/techcenter/display.php?QID=21

Mothereffer, if that page answers my question I'll flip out...I waited posting this thread for a whole day because I thought I could search and find it...

Third edit: Website says there are no complete drop-in replacements, but I want a second source.

Also, http://www.fiveomotorsport.com/electrical-connectors/ , that website looks useful for not hacking into the stock wiring harness if I can figure out what connectors go to what injectors and harness, etc.

 

[SURUKO]

pics of said injectors will be great and also which ones of the injectors of the rx7 the 4 ? the leading or the trailing ones ?

p.s. sorry OP for the hijack

 

[SideWinderGX]

I'll try to find some pictures but I haven't seen any to date of the actual clip from a straight angle.

In my reading I found out there are two 550cc injectors running all the time and two 850cc injectors that come on at higher rpms in the turbo RX7...not sure which ones are leading or trailing, I bet you'll know though.

I'll edit this post with pics in a few mins.

edit 1: This is a picture of higher impedence injectors, no idea how he came about 8 lol: http://i283.photobucket.com/albums/kk291/jcooper38/SDC10651.jpg

Low impedence injectors, which are what the 7MGTE uses stock, I'll find in a second...

 

[wardog]

What you guys are looking for is the 87-88 turboII injectors. I have a set with 6k on them for sale , they were rebuilt and flowed 550cc. Let me know

 

[RotaryHead]

its primary and secondary 550s are the primary and 850s secondary

 

[SideWinderGX]

What you guys are looking for is the 87-88 turboII injectors. I have a set with 6k on them for sale , they were rebuilt and flowed 550cc. Let me know

Ooh, cool quick reply box...

The earlier ones (87-88) are low impedence, so yes those will work, but will they fit into the stock 7MGTE wiring harness or will you need injector clips?

edt: PM me with price, I'm curious about that too haha.

 

[gotsomegetsome]

excellenth thread, I thought that was just a myth!

 

[SideWinderGX]

Nope no myth They can be finangled to fit or they are drop-in replacements, I'm trying to figure out which one. People have used them before and it might be my route as well, I can find em pretty cheap online (remanufactured) or from rx7club. Cleaned and flow tested and I should be set to go, I just want to clarify the injector clip situation.

 

[Mike Morris]

Been using them for years on my car.....fits right in

 

[3.0 GT]

i have the low impedence form an 87 and they aree purple top. injector clips are different and i had to change them.

 

[SideWinderGX]

Wardog also said that the clips would need to be changed to the RC clips.

Waiting on an e-mail back from the connector/clip place I linked to tell me what clips each harness has (7M/RX7) and if they have a connector pre-made that'll connect ours to the injector, if they are in fact different.

...still would like to hear from more people if they plug in or need clips anyways

 

[dragracer]

I ran the 550 high imp for several years. Worked and ran fine.

The low imp injectors were on 86 & early 87 Turbo II motors. Black body - tan top. These are RARE. 195500-1370 if i remember correctly.
The ones I had are 195500-2020 unfinished body - purple top (more red than purple). These were used on the series 5 cars (89-91)

Pic attached of the ones I used.

 

[MarkIII4Me]

I use the tan top. They are low impedence but need to have clips spliced in to replace the factory ones.

 

[Mike Morris]

I use the ones pictured up top. Clipped right in

 

[3.0 GT]

the tan tops actually used to be purple but then faded to tan.

 

[gotsomegetsome]

To summarize, purple top is the way to go, but you need RC clips?

correct me if i'm wrong.

 

[SideWinderGX]

Mmshay I'll be editing this post with my results.

So far I've found out that the 7MGTE wiring harness uses denso universal connectors, while the Mazda RX7 (early year, low impedance) uses EV1 connectors. So, to use the RX7 injectors in the 7MGTE harness you need a denso male universal connector to an EV1 female connector...which are sold here for $9.25 each: http://www.fiveomotorsport.com/electrical-connectors/

The low impedance injectors were made from 86-87.5, the high impedance from 87.5 onward, part numbers FI842-12172 and FI842-12173 respectively.

That SOGI link in my first post (http://www.supras.com/06/techcenter/display.php?QID=21) says you can use high impedance in a low impedance circuit, but NOT vice versa. I'll have to do more researching to find out if they will just work, no modifications necessary, or if you have to fiddle with the resistor pack like I heard from at least one source.

Right now I'm verifying if the high impedance injectors are PnP (as most people are saying), and if you really do need to remove the resistor pack (or bypass it) in order to run them.

More random information: http://www.robietherobot.com/storm/fuelinjectorguide.htm

Interesting thing about that is that the part number 195500-1370 is used for both low and high impedance injectors (86-87, and 88 respectively, tan top and purple top respectively). Makes me wonder if people bought the purple top 550ccs not knowing they were high impedance, shoved them in and they work perfectly fine.

edit: After more thinking, I think I'll get the injectors that require clips, and order the male to female clips from that website...therefore, if I'm ever in a pickle somewhere, I can use either 550cc injector (denso plug or EV1 plug). Plus, low impedance reacts half a millisecond faster, although that probably isn't large enough of a time to make a difference in any situation. BUT, I'm still looking into whether there's a difference in the clips between 86-91 RX7 injectors.

More injector info: http://www.fuelinjector.citymaker.com/MAZDA_FUEL_INJECTORS.html

 

[dragracer]

87.5 - 91 use the same oval plug as the Supra. Which are high imp injectors. The 86-87.5 do not use that plug.

You can use the high imp injectors with out any mods. I have for several years.
You cannot use low in a high imp system.

 

[3.0 GT]

if u decide to go with the low impedence and need clips this is where i got mine.
http://cgi.ebay.com/ebaymotors/Fuel...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
there only 2$ each and they are good quality. fast shipping too. im using them in my car and they also fit the cold start injector and pre 89 csi time switch and ecu temp sensor. i replaced those as well with these clips.

 

[hvyman]

wait what? im hearing that you can use both high and low impedance injectors on the same system with ill effects?