Text Size

Problem Injectors

Problem Fuel Injectors

Where they are and what to look for.

These problems can't be fixed by cleaning and the injector will need to be replaced.

If you injector is listed, one or more may exhibit the problems below.

Note: Any fuel injector can exhibit these issues but these injectors are prone to have the problems listed.


JEC's side-feed - Coil windings will increase in resistance.

Nissan, Inifnity, and Subaru (various top colors)

jecsprob1

Verify the resistance is within 10% of each other. Normally 10-12 ohms.



 

JEC's side-feed - Coil windings will increase in resistance

Nissan and Subaru (various top colors)

 

jecsprob2

Verify the resistance is within 10% of each other. Normally 10-12 ohms.
These also have issues with corrosion of the coil terminals causing intermittent operation. Fortunately the terminals can be cleaned during servicing.

 


 

Rochester Multec - Coil windings shorting out, decreasing resistance

These can sometimes be tricky to detect at home. When the injector is not being pulsed, the injector could ohm out to spec, but once they are energized the problem shows its effects and the resistance will rise or fall. Once this problem occurs, there is nothing that can be done other than to replace the injector.
These were commonly found on many GM models from the late 80's to early 90's having a grey or black top.


multecprob1

Verify the resistance is within 10% of each other. Normally 12-16 ohms.

 


 

 

Bosch top-feed external leaking from where pintle stem and main body meets, (just above lower o-ring). Also possible leaking where upper plastic meets metal body.

Mid to late 80's Porsches. Injectors from 944's very prone to this issue. Various part numbers in both gray and green.

 

boschprob1

 

Look for fuel leaking from where the top plastic meets the metal body. Also look for wetness around the bottom of the injector when it is installed.

 



 

Siemens, Deka or Bendix - External leak were plastic meets the metal body.

Late 80's Jeep 4.0

 

dekaprob1

Look for fuel leaking from where the top plastic meets the metal body.




 

Mitsubishi - External leak were plastic meets the metal body.

Late 80's Turbo 2.6 Starion, Conquest, etc

 

Starion1d

Look for fuel leaking from where the top plastic meets the metal body. A very common problem.