1.7 Fuel injection system

Matthew · Matthew's Garage

I just received a 1972 914 with a 1.7 L motor. it appears that one of the fuel injectors is leaking fuel. When trying to start the motor a small puddle of fuel forms under one of the injectors. How hard is it to change out the injectors on this motor and how much do they cost? Would it be best to replace them all at the same time or is it ok to change out just the leaking one? Any advice will be appreciated. Thank you.
Matthew

dman007 · 05-24-1998, 06:05 AM

I am not an expert on the four cylinder motors since I have a six in mine however, I helped my brother recently replace the injectors on his motor and it was very easy. Each injector has one nut holding on a reatining ring which holds the injector in place. You will also have to remove the electrical connector and the fuel line from the fuel rail. There are two seals on each injector. One on the very end and another larger seal where the injector goes into the head. As far as replacing them all, I don't know. I know there is a test to see if your ijectors are putting out enough fuel. I believe you have to have the injector out of the motor but hooked up. You then measure the fuel output over a given period of time to make this determination. I am sure someone else can better give you these instructions. Good luck.

Wayne 962 · Wayne 962's Garage

The replacement of the injector is pretty easy. The hardest part is making sure that you don't spill fuel all over the place.

Dman is correct, the procedure for measuring the injector flow involves pulling the injector out and then cranking the engine and having it dump fuel into a glass jar. This is how you can tell if the injector is working and spraying a good pattern. However, I'm not really sure how to measure the correct quantity of fuel.

If you are going to replace one injector, chances are that the others are on their way out too. I almost always replace things in sets; I assume that I'm going to have problems with the others real soon.

We have sets of new and used injectors in stock. All used parts come with a 30-day guarantee...

Hope this helps,

Wayne

Paul914 · 05-24-1998, 08:38 PM

It probably wouldn't be a bad thing to test all the injectors and replace as nec (all or some), but if your problem was just leaking fuel, I'd say just change the seals! Easy and cheap - definitely change them all (shouldn't cost more than $10 and takes less than 1 hour) - that'll solve the leaking fuel problem. Then just monitor how the car runs, and check the plugs (start with new ones) after a little while to make sure they're all the same color .. if they are, your injectors are probably all good - if they're not (i.e. one or more covered in soot or burnt), then you know you could have a problem with one.

Paul914 · 05-24-1998, 08:41 PM

One more thing - while you've got the injectors out you should replace the small piece of fuel line that goes from the rail to the injector (especially if they still have the "crimped" end on the injector side) - grind/cut the crimped metal off and use hose clamps .. it makes life much easier down the road if you ever have to replace the line again (so you don't have to pull the injector again) ..