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Discussion Starter #1
Are there differences between injectors on the B20's and B21's? I'm wondering if there is a difference and it's causing my mis-fire. I had to mix and match them because some of the B21 injectors where leaking (and one broke).

Anyone?
 

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no mo mod
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not that I know off
I had the b21 injectors in my b20 when i did my swap...one started leaking so I thought it was broken...when i pulled them out, I noticed it was an o ring that had been pinched
I put the b20 injectors in anyway and it ran fine...til the head seized
probably a clogged injector
 

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Discussion Starter #3
Looking at some posts on honda-tech.com, I don't think I can mix and match them...


Quote, originally posted by truent »
obd1 injectors.. no resistor box.
obd0 injectors.. resistor box..



Quote, originally posted by TravSi »
opeak/hold injectors which is what obd0 hondas run
saturated which is what is on the obd1 honda
 

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Discussion Starter #5
I think I'm going to swap o-rings and put the B21's back on. Hopefully no leaks...it at least eliminate this from being the cause of my mis-fire!
 

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Discussion Starter #6
Figured I'd update this post. I swapped in the other injectors (the B21 injectors) after swapping good o rings onto them and she purrs like a kitten w/ warm milk.

So, some have used all 4 B20 injectors in a B21 engine and harness w/o problem but at the same time, you can't mix them apparently.

Lesson learned...maybe add this to a knowledge base if one exists?
 

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Daily Interlude said:
Are there differences between injectors on the B20's and B21's? I'm wondering if there is a difference and it's causing my mis-fire. I had to mix and match them because some of the B21 injectors where leaking (and one broke).

Anyone?
I'm sure there is a flow rate difference, as they have different part #s. I have 1989 B20 injectors in my 1991 b21 right now and the Bosch # on the injector body is different than on the B21 injectors I took out.

Daily Interlude said:
Looking at some posts on honda-tech.com, I don't think I can mix and match them...

Quote, originally posted by truent »
obd1 injectors.. no resistor box.
obd0 injectors.. resistor box..

Quote, originally posted by TravSi »
opeak/hold injectors which is what obd0 hondas run
saturated which is what is on the obd1 honda
Then B21s must run OBD0 injectors, because we DO have a resistor box. Guaranteed.

Like Tsiah said, you might have one or more clogged injectors, or the flow rates are different enough to throw off the O2 sensor(s).
 

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the B20 and B21 both use part number 06164-PK2-010 there is absolutly NO difference in the injectors, dont let anyone tell you different. kthxbye :mrgreen:
 

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Discussion Starter #9
Well, I don't know what to tell you all. I checked the injectors as I was taking them out and putting the working ones back in. They all looked good and ohm'd the same but with the mix of B20 injectors out of an 88 and injectors out of a B21 (don't know the year...from a friend), the car ran like do-do.
 

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maybe you have a bad injector? I looked up every injector stuck in every possible 3rd gen (except for the S model for obvious reasons) and they all have the same part numbers, so that is not your problem. You might have a bad injector, or need new seals cause something is leaking or something like that.
 

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Discussion Starter #11
I checked the part number too and saw that they are the same.

No leaks and they all OHM'd out the same and within spec. What else could have been wrong?

Do they flow different amount of CC's?

I only ask cause I want the next person researching to know facts.
 

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they are the exact same for B20 and B21 OR Honda would throw a different part number at each injector. I've worked for Honda about 6 years now. I promise you that the injectors are not any different, one may be bad, or the wiring up to it may have a problem. But honda is very anal about part numbers. :roll: Just trust me, for once I know what I am talking about :p there is A LOT of crap info in this thread, and I just want to clear things up.
 

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Discussion Starter #13
Crap info? I'm telling you what my real world experience was. With a mix of injectors, it didn't run right. I tested all the injectors (B20 and B21) the way the manual states too (ohm testing between 1.5-2.5) and they all tested the same.

Crap info or not, this is what happened :roll:
 

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Red89LudeSi said:
they are the exact same for B20 and B21 OR Honda would throw a different part number at each injector. I've worked for Honda about 6 years now. I promise you that the injectors are not any different, one may be bad, or the wiring up to it may have a problem. But honda is very anal about part numbers. :roll: Just trust me, for once I know what I am talking about :p there is A LOT of crap info in this thread, and I just want to clear things up.
Check again!!!

I told you I have both 1991 B21 injectors and 1989 B20 injectors and guess what...

THEY HAVE DIFFERENT PART NUMBERS!!!!

Direct from Majestic Honda:

1991 2.05SI:
http://www.hondaautomotiveparts.com...&catcgry4=KA5MT&catcgry5=INTAKE+MANIFOLD+(SI)

2989 2.0SI
http://www.hondaautomotiveparts.com...&catcgry4=KA5MT&catcgry5=INTAKE+MANIFOLD+(SI)

Honda DOES list different part #s.

When I get time to dig up my injectors I'll post the actual part # molded into the injector housing.


Now...


If you had specified that you were comparing part #s from 90-91 2.05 with 90-91 2.0 then yes, the part #s are the same, but I stand by my original assertion the in 1989 they were different. That could pose a problem if he was mixing the different years.
 

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I tried to use those numbers from Majestic before and my Honda dude couldn't find anything by them. So I don't think those are actual part numbers from Honda. It's just what they use for their website to distinguish them. But I am sure they aren't actual Honda OEM numbers.
 

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Discussion Starter #16
Well, when I called Honda, I had them check a 91 Si with B21 against the B20 from an 88. He said they where the same. :?:

I also saw that hondaautomotiveparts.com had different reference numbers for injectors (but remember that's not Honda's part number). If you look, there are actually 2 reference numbers listed. The second ones on both match each other. Actually I just checked your link and you're comparing an 89 and a 91 and none of the numbers match. If you compare an 88, the second numbers match.

It's all confusing.

I'm just sticking my my story which is all based on fact. I tried 88 Si B20 injectors mixed with 91 Si B21 injectors and it didn't run right. I checked each injector and they all tested out good (according to how the manual tells you to check them).
 

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I sent four injectors from an 89 B20A to RC Engineering to be cleaned and balanced. One of them was bad, so I pulled one from a 90 B21 that I have and sent it to them.

The 'before' flow was 220.8 average. After I got them back, the average flow was 248.9. I guess my point is - it didn't matter if it was from a B20 or a B21.
 

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Discussion Starter #18
Well, I don't know...maybe one of them was bad. Is there any other way to test an injector beyond doing the ohm test?
 

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Yeah you take out each injector one at a time and let it squirt fuel into a beaker and measure how much there is within a certain time-frame (say 10 seconds). The one with the least amount of fuel is clogged partially :lol:
I forgot exactly how to do that test, but i've been told about it by my uncles old mechanic bud.
 

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Daily Interlude said:
Well, I don't know...maybe one of them was bad. Is there any other way to test an injector beyond doing the ohm test?
Best way I know is to do what I did and send them to a shop that cleans and adjusts injectors. RC Eng. charges $100 to do four. You UPS the injectors to them - they take one or two days to do them, and then they UPS them back. It all can be done in a week, and is a whole lot cheaper than buying new ones.
 
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