Suspecting I have a leaking fuel injector. I was wondering if anyone would have any tips on finding out which one it maybe. The text book way is to remove all of them and pressure test them. Short of doing that, I could put the spare one I have in position number 1 and and see if the symptoms continue. I could probably do that swap in about 10-15 minutes.

The symptom are: hot engine, shut off for between 5 and 10 minutes, re start engine run rough for about 10 seconds, reving clears it out and all is fine.
Fuel pressure regulator is about 6 months old and vacuum hose to it is clear.

Maybe someone has a trick of the trade they would like to share.

Thanks in advance.

DanR 964 964 332,000 miles (98,000 on the new engine)
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DanR

If you have the time, replacing them one at a time and checking for a change seems the lowest cost way to find the faulty component, especially since they cost $125 a pop; just make sure your spare is good or you could go backwards. Another thought: if you didn't replace the injectors on the engine, with 332k miles, you may be looking at a bunch of worn injectors.

Yeah, you may be right. Yes, they are all still original. I did send them then to be cleaned. All came back with high ratings. It may be time to bite the bullet.

Thanks for the response.

Dan
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DanR

If you can afford the down time, pull all 6 and have them cleaned. Cruzin Preformance is very good to do business with :
http://www.cruzinperformance.com/


Otherwise, go for a short trip and when you get home, pull all of the plugs and verify which one is wet.
When my 6 cylinder did that, it was the result of a broken valve spring. But that was push rod days :)

Klaus
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Please answer, we need to know if the advice is good or bad. The 164 has a new home, all I am left with are 2 turbos :)

I was hoping for some old mechanics trick to help out but you are correct the best thing to do is get them cleaned, tested and possibly replace the bad one.

Thanks Klaus
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DanR

Hi, When you have stopped the engine, release the fuel pressure at the injector side of the fuel regulator VERY SLOWLY so as not to spray gas over the hot engine, put some rag under so that it is absorbed as you do it. After your standing time that you have used before, restart and see if you get the same results, if you do then you are correct about an injector leak, but if not then you will have to look elseware. My 960 is coming up for it`s MOT next week so to help the emmissions test I have put some STP injector cleaner in the tank. It is suppose to clean everything out, well it did that so well that i was going fast down the highway and the car started juddering mildly, so i moved over to the slow lane and then i was getting slower so i moved onto the hard shoulder and I was doing 4000 revs at about 40 mph what gear it was in I wasn`t interested i only wanted to keep the engine going. Well 2 miles later it suddenly went like a rocket as my foot had been on the floor for all this time.I think That STP had moved some crap and blocked a couple of injectors but they eventually cleared with the gas pressure being maintained. So after explaining all this you might have some crud stopping the injector closing properly. The 960 has behaved since then, two days ago. Regards Keith

Dan --if you pulled the injectors and left them in the frame that supports them and turned the ignition on--wouldn't the one thats leaking show up that way?
Poolman

Unfortunately that wouldn't work, they need the downward pressure from the fuel rail against the intake manifold to hold them in place. Without being squeezed between those two pieces they would just fall out.

There is a device shown in my fault tracing guide that dealer may have that clamps the injectors to a fuel rail like part and then pressurizes them for spray pattern, so it must pulse them too, imagine it is with a slightly less flammable liquid than gasoline.

It is the thought that counts, thanks.

DanR
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DanR

Could you pull the plugs and find the blackest or wettest plug and start from that point as to the injector thats the culprit?

I don't know why I did not think of that, thanks. Of course I would need to wait until the symptoms appear again, but I it is happening more often.

Thanks again.

DanR
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DanR

DanR;
If I might offer a note of caution: Do not turn on the ignition ever with an injector out of position. If you are going to check an injector for leakage or pattern, check it with an external test device, not under the hood. My son and I tried to check the injector pattern on a SAAB many years back by holding the injector over a bucket and turning the engine over. Had to call the fire department and afterwards we had to replace all the injector fuel feed lines. On that car they were made out of plastic.