Northstar Engines and System Technical Discussion Discussion, 97 Deville Concours - Rough Starting in Cadillac Engine Discussion; I just replaced the motor an transmission in oregon now i live in colorado an first start off the morning ...
I just replaced the motor an transmission in oregon now i live in colorado an first start off the morning it takes awhile to start like 3 to 5 minutes than it starts ruff than ill turn it off an it will start right up but the lights kinda flicker for a min than that goes away does anyone have an idea what causes it to have a hard first start.
Maybe on the left frame rail, just about under the driver's side rear door. Retainer bracket, quick connect and hex fitting. Bleed off fuel pressure at the fuel rail test port or you'll really get a face full of gas. Replacement filters at any large parts chain store.
Google "cadillac forums 1997 deville fuel filter".
Some one told me the idle air control valve could cause that too watchu think it gets codes 0171 an 0174 ill clean the maf sensor an the check engine light goes off but it still starts the same first start
These dam cadillacs are as bad as women there never satisfied.... I just put in a new tranny an had carroll custom cadillac rebuild my engine an now she dont wanna start i think there worst than women... jus sayin tho
The two lean mixture codes point directly at a decent sized vacuum leak, not a fuel filter. Start snooping for a hisssssss at idle in P - remove the engine cover and really snoop.
It's not the MAF itself, either, unless you have an intake duct air leak at or after the MAF. VERY seldom will "cleaning the MAF" do a thing for your problem. (Unlikely, as your MAF is bolted to the throttlebody ???)
Sure - Lean fuel mixtures can cause anything from hard starts to lousy idle to a midrange bog to nasty fuel detonation (hot cylinder/carbon chip/plug electrode = preignition).
Just for grins, here's a 10-minute fuel mixture check - cold hard start...............remove the air intake duct at the MAF - your MAF is bolted directly to the throttlebody ??? - and (door open and key ready to go) squirt a moderate shot of starting fluid into the MAF screen. Hop in the car and start it. Quick start ??? The starting fluid (ether-based) is more volatile than lacquer thinner - the engine should start immediately and run well enough for the ECM cold idle enrichment process to override the air/vacuum leak.
IF the engine lights off immediately, rather than a long crank, you have air/vacuum/fuel problems. Your codes point to an air/vacuum leak.
A failed FPR will normally cause excessively RICH mixtures, not the lean codes you have.
I believe that, in your car, the Fuel Pressure Regulator is in the fuel rail, just to the right of the rear part of the rail, looking over the engine from the radiator. A domed thingy with a vacuum line attached to the throttlebody casting by a plastic pipe. To test the FPR, remove the engine cover, start the car and let it idle. Carefully remove the vacuum pipe from the nipple on the FPR - if there's any fuel in the FPR nipple the diaphragm is ruptured. The vacuum line should have decent suction with a fingertip placed over the open end. Cadillac Tech Tips.