348 Fuel Injector Change Process?

I would not use teflon tape on the fuel connections. The threads do not need to be sealed, as the mating surfaces of the connectors do all of the sealing. You will do more harm than good by using the tape.

 

No Doubt: is this recommended? does this improve performance?

 

Your a brave man

But nobody is better equipped than you to do this good luck.

 

you should compare spray patterns to the stockers.

I'm running 30# ford motorsport injectors (red tops at the link below) . .. lots of options out there in that body style.

http://www.fiveomotorsport.com/Injector_SetsMODS.asp

 

It has been my experience that simply slapping in larger injectors will cause a rich condition and you will LOSE power.

If your engine has been modified extensively and you need a bit more fuel to correct the air/fuel ratio, a slight increase in fuel pressure is all that is needed.

Using a larger injector with lower fuel pressure to maintain correct air/fuel ratio will result in a lousy spray pattern.

Scott

 

So you are installing the Porsche spec injectors or 355 injectors?

 

I'm a little incredulous that you are spending $4800 on 355 injectors. Particularly with the usual frugality you often talk about.

 

This should be interesting.

 

Well then they aren't $600 to $800 each, are they?

 

The 348 ignitor and coil cannot fire the 355 injectors IIRC. We tried that on Plugzits car during the ITB swap. We had to put the 348 injectors in to ge them to spray fuel. Check with Ernie and Bruce I'm 90% I remember that correctly

 

From this angle this injector looks the same as yours and the Ford motorsport injectors that I'm running in my car (and pictured at the link I posted) . . . but there is a significant difference up inside the tip which you can see with the naked eye . . . I'd compare them.
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to get them to spray period? . .. that doesn't seem right based on those resistance values . . could see it not running properly though but I haven't played with the stock motronic ecu yet . . . it's been my understanding there are basically two kinds of injector drivers and you can piggy back a black box if you have the wrong driver . . .but with those resistance values seems like same type . .. luv my Haltech .

 

I remember that.

When we put on Plugzit's 355 ITBs the 355 injectors were left on. The car wouldn't fire, so we swapped out the 355 injectors for the 348s and then it fired up. I don't remember exactly why, something to do with the resistance maybe????? Bruce has swapped out his injectors a couple of times, so he would know better than me what the deal was.

 

Is there some way to test your injectors at home, to make sure they are faulty, before replacing? I seem to remember that on the 914 you can cut out the spark, and then shoot fuel into a cup. Some old mechanic also told me they used to use compressed air and a car battery to check the spray pattern using water... any one heard of this?

 

I think you can energize them "for a short while" (a few seconds?) but have to be careful about overheating the coils . .. I worked with a fuel injection test bench where I could alter the injection times and total number of pulses for calibration . . . I'd like to rig up one of my Haltech ECU's to do the same thing.

I think the test you're referring to would work with CIS injectors but not EFI.