Removing Injectors MFI
 

I have an 86 Carrera and I was trying to remove the injectors to have them cleaned...looks easy in the Bentley manual but I have had trouble removing the injectors after I have loosened all of the bolts and fuel lines. They won't release from the intake manifold.

I tried pulling straight out and prying with a screw driver but no luck. I was afraid to pull too hard. I contacted Marren and they said that sometimes these injectors won't come out due to previous owners using lubricant that couses the o-ring to expand. What is the best way to remove these?

Pull hard. They are just pushed in with an o-ring seal to the fuel rail. By the way, you have EFI-electronic fuel injection. The injectors are opened with electric pulses from the computer. MFI=mechanical fuel injection usually associated with the early 69-73 fuel injected cars. Pressure from a high pressure fuel injection pump opens them. No big deal but when discussing with others it helps to be using the same terminology.

Cleaning your injectors will help any running issues you have. I think on the computer cars it should be the first thing you do before trying to diagnose poor running issues. Good luck.

You need to have the fuel rails completely out of the way.
They will pop up out of there and the seals get replaced when you send them out for rebuild.
Bruce

I didn't mean mechanical I meant Motronic...I will try to pull them off without the fuel rail. I thought the bolts would be the hardest part of this.

Bruce have you had any trouble removing these? They seem to be stuck but maybe without the rail I can get more of a grip.

I pulled mine a few months ago and recall that when I tried to pull all at once with the fuel rail I did not get them out. Once the fuel rail was removed they were pretty easy to get out. When doing one at a time you can put a little back and forth motion to help work them out.

Some rubbers swell when in contact with different types of oil. I would expect the rubber speced for the o-ring seals on the fuel injectors would not be effected in this way but if someone got some o-rings (hardware store or such) which were this could be a problem and be more difficult to remove.

Where do you plan to have your injectors cleaned?

After removing the injector fuel rail, use expanding pliers. Place jaws between hard surfaces, then squeeze to slowly separate the injector from its holder.

Sherwood

I finally got them out but am having a problem with the right front (back of engine) fuel line connection. I assumed it was similar to the left side with threads that loosen counter clockwise. I have deformed the fuel line by turning the fitting. I hope I can get this loose.

I was going to send them to Marren for cleaning...they have 150K. I also was wondering if an update was needed to improve spray and power? Does anyone know the flow rate of the stock Carrera injectors? The Marren site has a calculator that describes the flow rate (27 lb/hr) and duty cycle (289 cc/min) needed for 250+ HP. I want to make some changes and 250 is my goal.

Max. fuel requirements will depend on the needs of the engine and your proposed operating conditions. First, decide on your build specs (bore, stroke, comp. ratio, valve train, fuel/ign. timing control, etc.). After that, a more accurate fuel delivery estimate should follow.

The archives can help to give you a better idea of FI flow rates.

Sherwood