Ok, heres the question. TO my understanding, all yellow injectors are low imp, and red are high imp right? They changed the imp in 88, so some cars have low, and some have high. I have some spare red-topped injectors that came with my j-spec, and was wondering if they would work in a 88 that uses red topped injectors. I want to make sure they will, cause I dont want to sell injectors to someone who cant use them.

 

Forget the colours(heat and age changes them anyway),just measure the resistance:
1-3ohms =low impedance;12-16ohms=high impedance

 

Ok, but I dont want the person im selling them to have to rip apart their intake to check the resistance. Its easy for me cause theyre out of the car.

 

I believe the tab for the connector is off centered on the low impedance ones.

 

God damnit why cant this be easy.

 

All you have to do is look at the connector and see where the raised tab is. It is easy.

 

I believe that the high impedance injectors had round connectors. The low injectors should have square connectors. Jay
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Sorry my bad...See Mazdaspeed post below. If it oval, for sure it high impedance.

 

All the connectors are square. Just the tabs are different.

 

The S4's had square connectors, the S5 had oval. The impedence switch was in 87, so theres both high and low impedence injectors with the square connector.

 

So no color will distinguish?

 

Yes it will. If they are red, then they are high impedence. If they are purple/brown/yellow (those are all purple but heat aged differently) then they are low impedence. he can also check to see if he has the resistence pack next to the passenger side headlight to see if they are highs or low.

 

Better yet, the 88's had high imp?

 

He said his were definately red, he has an 88 GTU.

 

All the 88s should have high impedance.

 

You are wrong on the purple. S5(oval connector) 550 cc injectors(TII) are purple. S5 460 cc injectors(n/a) are red

 

Correct, the impedence switch was mid 87.

 

I just tested them, both 12.4 of resistance.

 

My stock injectors are were (changed them out already) red, oval ones. I think the colors are different and may not represent much...I have heard many people having different color injectors on the same car year/model.

Jay

 

I have (10) 550cc injectors out of 2.5 S5 motors and they are all red.

 

I have 8 460 cc injectors out of a 90 GTU and an 89 GTU, and all are red. I have 2 purple 550 cc injectors from an 89 TII. I think color is BAD way to tell the injectors apart.

I must say, between the injectors and wire colors, Mazda needs to stop changing so freaking often. My 90 n/a engine warign harness has some different colored wires than my 89 engine harness. Its completely retarded.

 

Agreed totally! maybe mine are all heat rinsed so they appear red. LOL I know that they are 550cc and that is all that is important!

I think best way to check impedence is to just measure them. It isn't hard to pull off the upper manifold. Hell, the N/A is even easier than the TII IMHO.

 

To confuse the issue;
This past weekend I pulled low impedence (2 ohms) red injectors out of my '87 N/A.

I have sent them out to get cleaned. When they come back I will attempt to remember to post their part numbers that are embossed on the side of the injector. Is there a list of injector part numbers that we can use to I.D. injectors? If not, let's start one.

-john

 

Screw colors. They don't hold the color over time. Use part numbers. You've got some high impedence injectors but not a clue whether they are 460 or 550. Got some part numbers? Its right on the side of the injector. Something likea -1350 or -1370
Try this thread and Lars Young: https://www.rx7club.com/forum/showth...threadid=40835
And to assure that you are totally confused, whats to stop someone from taking a 460- and sending it off to RC and having them make it a 550? Then how could you tell? You could flow it yourself into a measured container, I suppose.