PAUL T Posted July 13, 2019 Report Share Posted July 13, 2019 I recently had to change the PCV hose that comes out of the intake manifold and goes to the rear valve cover on my father-in-law’s 2003 Deville. In doing so I had to lift up the intake manifold and remove the fuel rail. I had to pull out the injectors when I removed the fuel rail. Put it back together and now I have a P0300 and stumbling at stops. I am suspecting an injector problem. How can I check the injectors? I checked the FPR and it was fine. I cleared the codes and will check them again later. Quote Link to comment Share on other sites More sharing options...
rockfangd Posted July 14, 2019 Report Share Posted July 14, 2019 Did you replace the seals when you pulled them? I would have. Hook up a scantool and it will tell you which cylinder(s) are missing 0300 is just a generic miss code. Does not help at all Quote GM FAN FOREVER Nice, clean, luxury= fine automobile Link to comment Share on other sites More sharing options...
BodybyFisher Posted July 14, 2019 Report Share Posted July 14, 2019 I agree, those seals are 16 years old now, I would have changed them also. Did you lube them when you reinstalled the rail, it helps you to reseat it, which can be tricky. Make sure you use O2 sensor safe, non petroleum based lube. Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
PAUL T Posted July 15, 2019 Author Report Share Posted July 15, 2019 I did not replace the seals or grease them so I will start with that and let everyone know if that fixed it. BodybyFisher 1 Quote Link to comment Share on other sites More sharing options...
PAUL T Posted August 4, 2019 Author Report Share Posted August 4, 2019 I replaced the injector seals and applied the grease when reinstalled, but the miss is still there. I talked to my father-in-law and he said a caddy mechanic had replaced the front injectors but not the back, so that is what I am suspecting now. Quote Link to comment Share on other sites More sharing options...
BodybyFisher Posted August 4, 2019 Report Share Posted August 4, 2019 5 minutes ago, PAUL T said: I replaced the injector seals and applied the grease when reinstalled, but the miss is still there. I talked to my father-in-law and he said a caddy mechanic had replaced the front injectors but not the back, so that is what I am suspecting now. Consider sending them out to have them cleaned and flow tested rather than replacing them. I am not sure but you might also be able to check their resistance against a known good lifter or the FSM spec if its in there to try to disclose the bad injector. Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
rockfangd Posted August 7, 2019 Report Share Posted August 7, 2019 Before you go any farther inspect the coil pack modules. I cannot stress how common they are to failing. I have done many of them. Pull them and inspect them for heat cracks. Other than a leak from disturbance I have never had to replace a injector on one yet. You also need to get a specific cylinder rather than tossing a coin. It could be either bank. A decent scantool will give you the p030* that you need to know which cylinder(s) it is Quote GM FAN FOREVER Nice, clean, luxury= fine automobile Link to comment Share on other sites More sharing options...
Logan Posted August 7, 2019 Report Share Posted August 7, 2019 On 8/4/2019 at 12:04 PM, PAUL T said: I replaced the injector seals and applied the grease when reinstalled, but the miss is still there. I talked to my father-in-law and he said a caddy mechanic had replaced the front injectors but not the back, so that is what I am suspecting now. Hmm......where were the injectors from? Aftermarket injectors rarely have the same flow rate as a original (GM) injector. The problems start when some injectors are flowing at x amount.....while the others are flowing at a different x amount. A injector balance test would show this. Quote Logan Diagnostic LLC www.airbagcrash.com www.logandieselusa.com www.ledfix.com www.ledfix.com/yukontaillightrepair.html www.ledfix.com/ledreplacements.html www.ledfix.com/j42385toolrental.html Link to comment Share on other sites More sharing options...
PAUL T Posted August 10, 2019 Author Report Share Posted August 10, 2019 I’m sorry I meant to say that the Caddy mechanic replaced the front coil pack module not the front injectors. I’m now suspecting the rear coil pack module. Going to have the caddy mechanic check it out. Thanks. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.