MFI injector variance
 

I had all my MFI injectors cleaned and checked .. one was in spec but had a dribble at idle. This is causing popping on that cylinder when at idle or near idle. The question is . . I have a new injector that was tested along with the old and its pressure is different. The old injectors all had a pressure rating at 225 to 230 and spray cones of 15%. This new injector has a pressure of 240 and a 20% cone . . will this variance cause any issues? I am trying to equate the spec difference to the cylinder burn and how different it may be on that one cylinder with the new injector. And no I do not want to get new injectors for every cylinder as there are expensive.

So I installed the new injector and solved the popping at idle problem . .runs strong . . I will have to read the plugs after some miles although that seems hard to do accurately on an MFI car.

I do t have a specific answer to your question, but keep in mind that MFI injectors are really just nozzles. Meaning they dispense the fuel sent to them, unlike EFI where the injector does the fuel metering.

There are MFI injector rebuilding services in case you want to have your old one fixed.

Thanks for the response but I was unable to find anyone that still does MFI injector rebuilds.

Try 356RS (Mark Jung - he rebuilds MFI pumps) here on the forum. If he doesn’t do injectors, perhaps he can tell you who can.

Yes Mark Jung is the guy who checked and cleaned the ones I have . . he didn't say that the drippy one could be rebuilt and I am sure he would have mentioned it if it was an option.