monoloco38 Posted October 12, 2019 Report Share Posted October 12, 2019 . I've been searching in the forum about rich cold start. I have a 1993 Cadillac deville 4.9 v8. I've done maintenance. full tune up. Plugs, wires, cap and rotor. New EGR, and new PCV valve. Throttle body cleaned and air intakes (those were bad) checked the timing yesterday (at 24 degrees) don't know why but I'll bring it down. Cold start rough... too much fuel. Runs perfect after warm. Any suggestions about the rich cold start? Any info it would be much appreciated. thank you. Quote Link to comment Share on other sites More sharing options...
Bruce Nunnally Posted October 12, 2019 Report Share Posted October 12, 2019 could the fuel be ok but not enough air? (replace air filter, ensure no obstructions) Quote Bruce 2023 Cadillac CT4-V Blackwing Follow me on: Twitter Instagram Youtube Link to comment Share on other sites More sharing options...
barczy01 Posted October 12, 2019 Report Share Posted October 12, 2019 I can't remember base timing on those with the aldl plugged in 6 degrees with the engine warm. Those balancers have a tendency to move spin a bit so you never know where you are timing wise. Quote Link to comment Share on other sites More sharing options...
monoloco38 Posted October 12, 2019 Author Report Share Posted October 12, 2019 Bruce plenty of air. New EGR and PCV. Cleaned throttle body and air intakes. Those were really bad. Almost fully closed with carbon. Its when the system is open. Close system runs beautiful. too much fuel when cold then it's fine. New air filter as well. Quote Link to comment Share on other sites More sharing options...
monoloco38 Posted October 12, 2019 Author Report Share Posted October 12, 2019 (edited) Barzcy01.... seems like the balancer might be off. It's 2 inches off the 20 degree mark and the car runs fine warm. Computer says between 22 and 24 derees. All vacuum lines secured and checked. Good power when warm. It's just the cold start. Suggestions? Edited October 12, 2019 by monoloco38 Quote Link to comment Share on other sites More sharing options...
monoloco38 Posted October 13, 2019 Author Report Share Posted October 13, 2019 Well guys. Found the problem. Just like the intake air ports the catalytic converter was clogged up. One bottle of cleaner and a muffler later and it's running smooth. Yes, I blew up the muffler. Literally. But its running smooth now. Lol. Quote Link to comment Share on other sites More sharing options...
Bruce Nunnally Posted October 13, 2019 Report Share Posted October 13, 2019 Oh good you got it fixed; thanks for posting what worked. The part where you blew up the muffler sounds like it needs a longer story. Quote Bruce 2023 Cadillac CT4-V Blackwing Follow me on: Twitter Instagram Youtube Link to comment Share on other sites More sharing options...
monoloco38 Posted October 14, 2019 Author Report Share Posted October 14, 2019 It sure does Bruce. Cut out the catalytic converter today and the car is running worse after a test drive. I'll have to do a compression test and a fuel pressure test next. Plus get a new muffler installed. the joys of owning an older vehicle. Keep you posted. Quote Link to comment Share on other sites More sharing options...
monoloco38 Posted October 22, 2019 Author Report Share Posted October 22, 2019 Fuel test completed. Fuel pump was a little lazy, but not out. A bottle of sea foam with a full tank of Shell 93 octane. Let it sit for a few days and it seems it cleaned out the fuel pump and injectors. Running smooth for the past couple of days. Quote Link to comment Share on other sites More sharing options...
BodybyFisher Posted November 2, 2019 Report Share Posted November 2, 2019 Glad you are making progress, sorry I didn't see your DM on 10/11, I didn't see it till today. It sounds like your muffler was collapsed inside. Odd that it would run better when warm though. Did you put a new CAT in? I had a CAT go bad, it wasn't clogged it just rattled loudly. I had a clogged CAT on an 01 Monte Carlo, no power whatsoever, 01 was a bad year for CATs. 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...
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.