XC70 injector leaking internally? Topic is solved

[jkatz]

I used peppermint/oragex’s cleaning method and it worked exactly as he says it should. I don’t know if the injectors are cleaner after flushing back and forth with carb cleaner, but the method easily identified the injector to cylinder 1 as the leaker. I built the spray can-to-injector adapter out of 1/2”id heater hose, with a few inches of 3/8 fuel hose slipped into one end, and then I wrapped electrical tape around the straw to the can until it was snug in the fuel hose. Then all joints got a hose clamp.

I happened to start with #1, and while it was obvious that it was not closing I was not sure whether I was evaluating it correctly until I did #2. The second one held pressure and only opened when I connected the 9v battery, as did 3-5. Actually 3 was a little sticky at first but seemed to close after three or four clicks of the battery. The spray pattern of all 5 seemed ok, and they all tested right around 12.8 ohms, so I guess this was the only way for me to do make the diagnosis.

The solenoid action of 1 was definitely weak compared to the firm click in 2-5, so I could have probably done my parts order based on the acoustics, but I just guessed and bought two new Bosch injectors from FCP and 10 new o-rings. I went ahead and replaced both 1 and 3 injectors as well as the o-ring for the inlet hose. I think 3 was borderline so I’ll toss it in the old parts box, but 1 will get tossed in the trash.

To be totally honest I haven’t tried starting it again after the test drive, but given the definitive results I’m pretty sure this problem is behind me. It also cured a problem where the engine felt like it was loading up when I rolled up to a stop sign, which i assumed was due to a vacuum leak but now think it was actually flooding cylinder 1 on deceleration.

Thanks for the help everyone!

[jonesg]

mark it solved.

[jkatz]

I drove it for a day or so, I’d say it was 90% fixed. It still sometimes took a few strokes longer than I want before it started, so I replaced the remaining 3 injectors with new ones. Now it starts after the 3rd compression stroke every time: arr-arr-arr-vroom! With only 2 new injectors it often took 5 compression strokes: arr-arr-arr-arr-arr-vroom. If anyone else has doubts about their 175k mile injectors go ahead and change them all, they’re probably holding the engine back.

With a completely brand new Bosch fuel system (pump, filter, pressure sensor, and injectors) I’m finally getting the advertised mpg: 22 city/26 highway, up from a low of about 18 city/21 highway when I took possession of the car.

[swedishpig]

It sounds like you actually didn't fix your root problem. You probably have a slow head gasket coolant leak that's fouling your plugs. You are making it sound like the new fuel injectors helped but they really didn't. You wasted time and money and it still is not repaired.