Injector troubleshooting

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Mar 22, 2010 | 10:12 PM

ccg711

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Joined: Apr 2006

Posts: 337

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From: West cental Texas

Injector troubleshooting

Ok so now that I have my long block in and I've put 2K+ on it I seem to be having injector problems. I'm needing help in troubleshooting so I can replace the appropriate injector. Now here's the situation. Trucks smokes a lot when cold. Think dark grey smoke. and there's a noticeable miss when cold. Once the engine gets some heat to it I can romp on the go pedal and make the miss stop. However there is still smoke, but it thins out considerably. I have AE and the buzz test seems to work. The cylinder contrib test shows cyl 4 fault as the engine is heating. once up to temp the test shows cyl 5 fault all the time and an occasional cyl 1 fault. Here's the trick. cyl1 and 5 have had the injectors replaced already so I suspect those codes are phantoms codes. Also I have a regulated return system and I can see the fuel pressure surging while it runs a total pressure width of 4-5 PSI according to the glycerin filled guage on my regulator. Also I'm wondering if I'm dumping excess fuel into the oil as I have some signs of that but I can't be completely conclusive about it. I would like to use the PERDEL readings on AE, but appearently early 99's don't have that capability. My stethoscope and IR thermometer don't give me any clues. any one have any tricks to figure out which injector it might be?

Thanks
Chad