*Updated* JA Injector Differences - Answers

[JPC]

I've noticed that there are two types of injector setups on JAs. One type (presumably from series 1 JAs) has a black plastic electrical connector with round pins; the other (presumably from series 2) has a brown plastic connector with flat pins.

There are also physical differences with the injectors themselves: the ones with the black connector (round pins) have the solenoid wires coming from the side of the injector body through a square rubber grommet; the ones with the brown connector (flat pins) have the solenoid wires coming from the horizontal flat face where the upper rubber boot sits - the rubber boot has holes in it for the wires to exit.

Connector differences notwithstanding, are the two sets of injectors compatible?

Update, 06 Sep 2004:

I've just got a bunch of injectors back from an EFI place - here are the flow results:



Interesting. In case you can't see the engraved numbers on the injectors, they are 1 to 5, left to right.

#1 and #2 are a pair from one car
#3 and #4 are a pair from another car
#5 is one of my originals (series 2 JA)

Looks like David was partially right - #3 and #4 are only ~70% of the flow of all the others. The bastard bit is that #1 and #2 look physically identical to #3 and #4

There is yet another type, with a much larger top rubber boot, but it's stuffed so I couldn't get the flow rate measured.

Looks like the only way to tell what flow rate you have is to have it measured. What I still don't know is whether there are injectors that look like #5 but have the lower flow rate. Bugger.

..and no comments about MPI and aftermarket ECUs, please :glare:

[David]

Not unless you change computers as well.

They have different flow rates.

Regards
David

[decoy]

so if the flat pin ones came out of a s2ja, that would mean the ecu is different to the s1... but the tb setup is the same, different to the JB and JD ones... which each in turn share the same injectors and ecu? ahhhh i'm lost.. ignore that

[JPC]

Not unless you change computers as well.

They have different flow rates.

Now I'm confused! I just cracked open another injector assembly. It all looks original - original (brittle) wires, no joins...and it has one injector of each type

Assuming what you said is true (and ignoring what I just said above), is there any way to tell if the ECU is different? I have a couple of ECUs and injector assemblies (round pin + flat pin), but the ECU that came with each has the same part number

[Black JA]

wtf

[avandull]

Are you changing the injectors because they leak a bit?
If your original injectors are still half but leakey, you could always flow test them. and compare this flow rate to the newer injectors. If the flow rate is roughly the same then they will work with whatever ecu it worked with before.

[JPC]

WTF, exactly. Looks like I'll have to get the flow rate on these tested so I can get to the bottom of this!

[avandull]

Are you changing the injectors because they leak a bit?
If your original injectors are still half but leakey, you could always flow test them. and compare this flow rate to the newer injectors. If the flow rate is roughly the same then they will work with whatever ecu it worked with before.

[decoy]

wow, i usually delete double posts but jpc managed to post between a double post from avandull! well done... you get an injector as a reward :P what injector? flat pin but different type from a JD which had JA injection... series 2

[JPC]

wow, i usually delete double posts but jpc managed to post between a double post from avandull! well done... you get an injector as a reward :P what injector? flat pin but different type from a JD which had JA injection... series 2

I tried very hard to get in between the double post - I'm glad you noticed my efforts :)

Gimme the injector, any injector :D

[JPC]

Are you changing the injectors because they leak a bit?
If your original injectors are still half but leakey, you could always flow test them. and compare this flow rate to the newer injectors. If the flow rate is roughly the same then they will work with whatever ecu it worked with before.

I put in the (apparently) Series 1 injectors because one of my (allegedly) Series 2 injectors was leaky. The S1 injectors don't appear to do too well on boost in my car (fine when not on boost), so I put my S2 injectors back in and the boost problem went away. I am going to get the two types flow tested next week, so I can see what's going on.

In the meantime, anyone have a set of JA S2 injectors they'd care to part with? The ones with the solenoid wires coming out of the top rubber boot, rather than the rectangular grommet on the side...

[merlin]

every time i read stuff like this i think multipoint and aftermarket ecu is wonderful.
however, i do sympathise with you guys battling on with the original parts, or trying to anyway!

[JPC]

Sympathies appreciated, merlin

I do eventually intend to go MPI - but it takes time and costs money. The first I'm very short of; the second requires 'approval' from the other half

Plus, it's my daily driver.

[merlin]

ahh, money!
i believe i'm what u call a 100% money user.
meaning, i spend every cent i get, so i've never got any.
does that make any sense?

[Cookiemonster]

ahh, money!
i believe i'm what u call a 100% money user.
meaning, i spend every cent i get, so i've never got any.
does that make any sense?

No, but we'll just smile and nod to humour you.

*smiles and nods*