mjshira

none that I could find. but I found it to be very straight forward. you need to lube the injector's o-ring first and then carefully wiggle it in place. The fuel rail once re-installed, provides the pressure to hold the injector to the intake. The first step should be taking the fuel line at the rear of the rail loose, then the 10mm bolts that hold the rail to the intakes. There are small clips that hold the injectors in the specific injector ports on the fuel rail. These should next be removed. Then the rail can be moved to expose the injectors. I patiently pulled and wiggled the injectors one at a time until the came free. I then labled them so I'd know which cyl they were on before installing the new ones.

I had one dead injector and several that seemed to be tired. Again, the previous owner spent his funds on the rebuild and it seems that he left items such as these untouched.

slammed1000

john kit comes with 30lb. injectors
stock 964's are 24lb
stock 993's are 26lb.

pat056

mjshira
Found the injector on Pelican. Thanks! This is a very informative thread! I'll have to pull one this w/e and look at it. With a 3.8, I'm nor sure which one I have as Pelican shows 2 for my MY. Engines a '93 w/42,000 miles on it so don't know how worn they will be.

mjshira

that is not a lot of miles, I wouldn't worry. mine had 130k+ on them (20k on rebuild)

I am excited to see how this works out. Glad that a thread of mine might be able to help others as so many of others have helped me.

slammed1000

i would just send them out to be cleaned and flowed. for the cost of 1 injector you can have them as good as new and have a flow chart for each injector. some shops offer flow matching. in my opinion new injectors are a waste of money especially at $120ea. x 6 ouch...

mjshira

unless you are going to larger injectors Brent has a good point. since I had new ones already, I elected to just put them on. If I'd not had new ones I would have replaced the one bad injector and cleaned the rest.

pat056

Thanks! I may just pull one and check it out. My wife will tell you if I don't have something that needs attention on one my cars, I'll just make something up!!!

mjshira

It is fun to work on these cars, less fun when they are your daily driver... I am excited to get my car back and functional.

I'll post some pics of the injectors later.

I will also do a complete write-up on the MAF kit in a different thread.

mjshira

Well the MAF kit is on, the big injectors are working, but I've still got a lean condition and guys I am a bit lost here frankly. I am going to test vac at the intake so that I know the line going to the fuel pressure regulator is getting vac but I have to tell you, I can't imagine how she is going lean but she is!!!

Indycam

If you are running a O2 sensor , the computer should see the lean condition and richen it up .
If I were in your shoes , I think I would try another DME , just to see what would happen to the AFR .
How old is the O2 sensor ?
Is it a "Porsche" O2 sensor or an after market O2 sensor ?

Are you running a stock exhaust system ?
Does it have the heat exchanger covers over the exhaust "headers" ?

pat056

Can you tell any difference w/the new injectors? Any performance gains?
This sounds like a real mystery! I would have thought you were right on w/what you did. I was wondering about all the cylinders showing lean when the one injector wasn't hardly working at all, but what do I know??? I'm out of my league on this one.
feel for you!

mjshira

The DME is new... the O/2 Sensor is a new Porsche part but we had to splice it into the harness because they don't make those old ones anymore. Regardless it is a bosch part and the hammer is reading it. I've run the full diag with the hammer and key see timing being advance and retarded as a result of throttle position. I also checked WOT and all the ingition system switches. I also checked to see if the knock sensors were recording knock, they are. There seems to be more knock than there should be but regardless I remain focused on fuel delivery as the most probable cause because I can't imagine given the above what else it could be.

What if the fuel pressure regulator is not getting vac????? what would that do????

mjshira

the engine really wants to run, the throttle is much quicker and smoother even with this lean b/s.

This has nothing to do with the upgrade. It has everything to do with a mystery lean considition.

Indycam

If you put a fuel pressure gauge on the thing , you can read the fuel pressure up and down the rpms .

mjshira

I just need to know where to find the right fuel pressure gauge, that is next. Problem is you can only get the ping under load. So I'd need enough line to hold the gauge in the car while driving or have someone else hold it. Regardless, it has to be fuel, I can't imagine what else. I've got the fuel quality switch on the DME at full rich, I've got large injectors, new fuel pump, new fuel filter, new fuel pressure regulator.