injector ohm question
Thread Starter
Oil Producer
Joined: Apr 2014
Posts: 9,363
Likes: 2,734
injector ohm question
I have a 90 here that no longer has its original multecs. Im not sure what they are but they are not multecs.
anyway the have a serious range on thier ohm values when hot. from 17 to 10.
Cyl 7 is 10, and cyl 6 is 14. The rest range from 15.9 to 17.
the car is surging, has a very hard time getting the idle static, ive got tunerpro here and i have confirmed functionality and settings of the iac, O2, map, and tps.
Can one injector on the driver side (O2 sensor side!!!!) of 10, cause the O2 to read HIGH voltage (rich) and make the subsequent idle operation very hard to nail down?
Thnx VT.
anyway the have a serious range on thier ohm values when hot. from 17 to 10.
Cyl 7 is 10, and cyl 6 is 14. The rest range from 15.9 to 17.
the car is surging, has a very hard time getting the idle static, ive got tunerpro here and i have confirmed functionality and settings of the iac, O2, map, and tps.
Can one injector on the driver side (O2 sensor side!!!!) of 10, cause the O2 to read HIGH voltage (rich) and make the subsequent idle operation very hard to nail down?
Thnx VT.
Last edited by VikingTrad3r; Feb 24, 2021 at 09:31 AM.
Melting Slicks
Joined: Mar 2001
Posts: 2,149
Likes: 302
From: Timra, Sweden
If I am not mistaken all four injectors on each side use the same injector driver.
On the injector with lower resistance there is probably an internal short on the coil.
That injector will draw more current because of lower resistance. Even worse, the shorted part of the coil will act as a transformer with shorted secondary coil drawing even more current.
If the injector driver has an active current limitation, and it probably has, then the rest of the injectors might not get enough current to open as fast as they should.
The injectors should be close in resistance if they are the same type.
As you have a known problem with the injectors you should fix that first.
The idle problem might be related or not.
On the injector with lower resistance there is probably an internal short on the coil.
That injector will draw more current because of lower resistance. Even worse, the shorted part of the coil will act as a transformer with shorted secondary coil drawing even more current.
If the injector driver has an active current limitation, and it probably has, then the rest of the injectors might not get enough current to open as fast as they should.
The injectors should be close in resistance if they are the same type.
As you have a known problem with the injectors you should fix that first.
The idle problem might be related or not.
Le Mans Master
Joined: Feb 2005
Posts: 6,475
Likes: 565
From: Clearwater Florida
..... Fuel Injectors should ohm pretty close to each other ... 7 points difference is waaaay too much ... the PO may have bought some cheap Ebay injectors and you get the reward ! ... change them first .....
Drifting
Joined: May 2020
Posts: 1,661
Likes: 701
From: Baton Rouge, Louisiana, metro area
I just picked up a set of Bosch 3’s for my 91 from Fuel Injector Connection out of Georgia. They seem to be pretty respected among the forum.
I had a question when they arrived, I called, got a human, that human gave the phone to another human technician who immediately answered my question.
If you still have some questions about those readings, I would suggest you call them.
https://fuelinjectorconnection.com/
I had a question when they arrived, I called, got a human, that human gave the phone to another human technician who immediately answered my question.
If you still have some questions about those readings, I would suggest you call them.
https://fuelinjectorconnection.com/
