Fuel Injection for 1988 3.2 Ltr.

[LCorkum]

I am interested in finding out how to install new injectors in my 1988 Porsche Carrera Targa 3.2 Ltr. Fuel Injection System. I have read the forum on CIS Fuel Injection and wondered how this would relate to MFI.

I have a fouled plug in the centre cylinder on the drivers side, I assume this is #2, not sure the firing order. All other plugs are white in colour showing good combustion. I have installed New Plugs, Wires, Distributor Cap and Rotor Button. Still not firing on #2, middle cylinder, drivers side.

I found a cracked hose at the end of the pipeline coming from the Intake boot, I have put silicone tape on it to see if there was an effect but there is still a miss-fire in the cylinder. I have ordered this part to be replaced but do not think it is my sole issue.

Please advise if anyone has any other suggestion other than a clogged injector as I believe if you have fire the only thing missing from combustion is fuel and air.

I am not sure on how to remove the injector and I am sure if one is clogged the rest are not far behind so I would replace all six.

Is there any reason to suspect the micro switch in the cable lead to the injector, if so how difficult is it to replace?

Thanks,
Lloyd Corkum
1-10

[Flat6pac]

The 3.2 injectors are held in with a small brass colored retainer, slides on the horizontal between the fuel rail and the injector.
If you move the suspected injector to another location that will tell you if the injector is defective or there is another problem..I have had a head intake gasket collapse on a 3.2 and it took some looking to decide it was the problem. Each intake runner has 2 intake gaskets.

Bruce

[LCorkum]

Bruce,

Thanks for the advice, I will check it out and report back sometime next week.

Thanks Again,

Lloyd

[gtc]

I would suggest that you buy the Bentley manual for the Carrera. It tells you how to remove and replace the injectors.
Also, you can send the injectors out to be cleaned and tested before you spend the $$$ for all new injectors. Witch Hunter is well regarded.

[DRACO A5OG]

Pretty simple process when I replaced all my injectors after #2 went bad with BMW metal tipped injectors with same OEM specs. Be warned it is a very tight work area.

You are dealing with fuel so disconnect the battery, for safety.

Disconnect the injector wiring, disconnect the fuel rail (fuel will spill, get rags ready), slide out the retaining clips, lift rail off ( some of the injectors may lift off with it), pull the injectors evenly & gently but firmly as not to damage the engine case.

Second most important thing is not to pinch the o rings when reinstalling the injectors on the metal fuel rail and engine ( 2 per injector ). A pinched or torn o ring will create a leak. Ask me how I know. :-(

Purchase new o rings but save the old ones as back ups, Compare new o rings with old to insure they are like size.

+1 on Bentley, it saved my but on many occasions, especially torque settings.

[LCorkum]

All,

I have solved the problem at least for now, I had a cracked rubber hose on the intake copper pipe that I replaced, I put Injector Cleaner in the Gas and I ran the engine at 1800 for 20 Minutes to get it warmede up, then I tapped on the injector and the fuel rail carefully with a 1/4" adaptor chain link that was easy to handle in a tight space and not much weight so as not to damage anything. After that I let it run for another 10 minutes then came out to find it working perfectly. I suspect dirt was lodged in the injector and will put that on my list of things to get looked into next spring.

I have ordered the bentley book and will be able to see all the parts more clearly I hope when I get it.

Thanks for all the advice, it was needed and much appreciated.

Lloyd

[rokemester]

Originally Posted by Flat6pac

The 3.2 injectors are held in with a small brass colored retainer, slides on the horizontal between the fuel rail and the injector.
If you move the suspected injector to another location that will tell you if the injector is defective or there is another problem..I have had a head intake gasket collapse on a 3.2 and it took some looking to decide it was the problem. Each intake runner has 2 intake gaskets.

Bruce

These injector retaining clips are a puzzle. I can see where the slots fit nicely into the fuel rail cups, but there is not enough to get over injector base to hold them down. What am I missing? Thanks!

[rokemester]

I came back after a bit and is pretty obvious! The clip is positioned just below the injector rim. Hmmm. It’s a bit counter intuitive because you need to pull the injector up away from the fuel rail a bit to create enough clearance for the retainer clip to slide in.