Question: RESISTANCE IS FUTILE!

[English Guy]

Can anyone tell me what lowers the resistance on fuel injectors to the point they have to be replaced?Also are remanufactured/reconditioned injectors worth buying in the short term till funds become available?Cheers and a merry christmas to all.

 

[Toms007]

I can't help you on the first question, but I think the reman'd units will get you by for some time.

 

[TedC]

A coil is used to control injector fuel flow. The coil wire has a protective layer. If damanged, you can end up with an internal short that lowers resistance. Multec injectors used in 1989 use the flowing fuel to cool the coils, and these coil wires are exposed to additives and alcohol which can shorten injector life.

 

[c4c5specialist]

HI there,
Yes, to all of the above.
Truth is, ethanol and other fuel additives create the condition.
16.5 ohms is the actual specification for L98 equipped vehicles.
Remember, if one goes more than 2 ohms on either the drivers or passenger side of the engine, the entire bank of injectors will not work correctly.
Normally, when you get below 10 ohms, thats when hard starting can occur.
Allthebest, c4c5

 

[English Guy]

HI GUYS,thank you both for the info,very helpful.
Brian.

 

[tonylong]

Can anyone tell me what lowers the resistance on fuel injectors to the point they have to be replaced?Also are remanufactured/reconditioned injectors worth buying in the short term till funds become available?Cheers and a merry christmas to all.

One of CAC's members has rebuilt Bosch III injectors for a good price. They thrive on resistance - like the Borg.

 

[English Guy]

Cheers Tony lol,live long and prosper,Oh and merry Christmas
Brian.

 

[G Winter]

HI there,

Remember, if one goes more than 2 ohms on either the drivers or passenger side of the engine, the entire bank of injectors will not work correctly.

Allthebest, c4c5

You are saying that if an injector's resistance is down 3 ohms it effects the way the others on that bank work? Could you explain why?

Thank you
Glenn

 

[tonylong]

You are saying that if an injector's resistance is down 3 ohms it effects the way the others on that bank work? Could you explain why?

Thank you
Glenn

I believe the injectors are connecter in parallel, within each bank (side). That would have a major effect on the remaining ones - even more so with the low resistance's involved - 16 ohms. It could cause overheating at the least. I'm an electrical engineer, though, not an EFI guy. I could be wrong.

 

[TedC]

tonylong, You are correct. 4 on the right are in parellel and 4 on the left. So four 16 ohm injectors in parellel provide only 4 ohms total. 4 ohms on the right and 4 ohms on the left. The ECM can't pulse the injectors properly if the total resistance drops too low.

 

[southbay]

resistance

Can anyone tell me what lowers the resistance on fuel injectors to the point they have to be replaced?Also are remanufactured/reconditioned injectors worth buying in the short term till funds become available?Cheers and a merry christmas to all.

the design lll injectors are 16 ohm and they are acceptable between 14 and 16 ohm. Injectors dropping below 14 down around the 10 area is a definite sign that the coil is going bad and they should be replaced.
We are a sponsor for the CAC forum. Check out our website, we have the design lll' s, and if purchased though this forum you will receive a 10% discount. Just go to www.southbayfuelinjectors.com and type in discount code: sb1108 This offer will be effective until December 31st. Thank you for your time. Hope to do business with you soon! Happy Holidays!

 

[G Winter]

With only 4 ohms , then dropping to half or less, over an extended period of time can this damage the ECM ?
Also are the rest of the injectors subjected to lower current?

Glenn

 

[English Guy]

HI TONYLONG,Do you know If the cac member got the bosch injectors from the south bay guys?Thanks,Brian

 

[killain]

Where I live here in South East Pennsylvania the major fuel around is Sunoco, which the tech at my Chevy dealership strongly recommends to NEVER use as it has way too much Sulfur in it. Sulfur eats away at the tiny metal parts in fuel pumps and injectors. Shell is the best fuel as he tells me. It's one of the 'Top Tier' fuels.

 

[tonylong]

Where I live here in South East Pennsylvania the major fuel around is Sunoco, which the tech at my Chevy dealership strongly recommends to NEVER use as it has way too much Sulfur in it. Sulfur eats away at the tiny metal parts in fuel pumps and injectors. Shell is the best fuel as he tells me. It's one of the 'Top Tier' fuels.

You're correct. Sun still uses the thermal refining process which isn't as good as the "platinum catalytic" process all the others use. That goes way back in time to when Sun Ship refused to ship crude for Atlantic Refining. When Atlantic Chemical developed the catalytic method they licensed it to everybody except Sun. What goes around, comes around. Sun also has a different Ph and regularly mixing with others will create sediment in your tank.

I use Gulf, it's the only brand here than has no ethanol. I'd rather use Shell, but they all have ethanol. In the big cities Shell also has Super Premium - which is 100 octane without ethanol.

 

[TedC]

Glenn, I'm not sure how much abuse the ECM could take with lower total injector resistance. However, it sure doesn't take long for a few bad injectors to confuse the ECM. It is a simple check that I like to preform every year. The side effect is that if either bank (right or left) has just one really lbad injector, the ECM will not pulse either bank. The trick here is to measure each one (unplugged) and keep the one that is reading low unplugged. If ithe engine starts (running on 7 cylinders), you isolated the cause.

 

[c4c5specialist]

Hi there,
It has nothing to do with anything other than electrical flow through the injectors.
If one injector has LOWER resistance than the other 3, then all electron flow goes through the one bad injector. This, in turn, does not allow the use of electricity to open the injectors on the other 3.
The ECM has a default driver that, under EXTREME electricity flow INTO the ECM, will SHUT DOWN!!!.
This is a protection feature of the ECM>
That being said, I have never seen an ECM go bad due to injector failure, because it will protect itself PRIOR to failure.
Allthebest, c4c5

 

[G Winter]

Hi there,
It has nothing to do with anything other than electrical flow through the injectors.
If one injector has LOWER resistance than the other 3, then all electron flow goes through the one bad injector. This, in turn, does not allow the use of electricity to open the injectors on the other 3.
The ECM has a default driver that, under EXTREME electricity flow INTO the ECM, will SHUT DOWN!!!.
This is a protection feature of the ECM>
That being said, I have never seen an ECM go bad due to injector failure, because it will protect itself PRIOR to failure.
Allthebest, c4c5

Thank You.

Glenn