Northstar Engines and System Technical Discussion Discussion, '94 SLS smoking bad in Cadillac Engine Technical Discussion; This '94 SLS smokes bad, it is a white smoke, and will start about 30 seconds after starting the engine, ...
This '94 SLS smokes bad, it is a white smoke, and will start about 30 seconds after starting the engine, runs ok.
I pulled all the spark plugs wires and saw that the #4 and #8 spark plugs had oil all around them, I pulled all the plugs and turned it over 15 or 20 times, and looked down each hole, all looked the same, but #4 had a puddle on the piston head.
I pulled off that head,(left or front), and looked at underside of the head, the color on the #4 & #8 was a little darker black than the other 2, the cylinders looked good, the headgasket looked ok.
I took the head to a head shop, and they said it was warped to .004, and needed other work, (unrelated to my problem), they also said there was no cracks, cost to do this head work is $178.
Does anybody think that the warpage could have caused the smoking?
I can not pull the engine out to get to the other head, and I can't afford to pay the cost to have it pulled out for me.
If I pay the cost for the head work and do the labor to re-assemble, and it still smokes, I will be very tense.
It sounds like all that is wrong is an injector stuck open....or possibly the fuel pressure regulator is leaking inside the intake manifold. Nothing you describe indicates a problem of anysort with the cylinder head.
wow, that is good to know, I will be putting the head back on, all that goes with that big job, and I will check the injectors.
Is there a easy way to check them? I can check them with a meter, would the stuck injector shoot fuel all the time with the key on?
Automobile(s): White Diamond '03 DHS (with floor shift)
Re: '94 SLS smoking bad
I don't know about valve seals but if the head is off, I'd timesert it before putting it back on to avoid having to do it again. I have never heard of problems with the valve seals.
To check for a stuck open injector, put a fuel pressure guage on the service port on the fuel rail and turn the key on to pressurize the system. Check the fuel pressure and then turn it off. If it does not hold pressure then pull the fuel rail with the injectors attatched and turn the key on again. This time watch the injector tips to see if any are leaking or spraying.
I tested the injectors, they seem to be ok, but when removing the head I bumped them around a little, this may have unstuck the stuck one.
The problem may have been with the wiring to the injectors, I inspected the wires from the injectors to the big connector, and 4 or 5 of them had insulation missing, exposing the wire to touching the trans. case grounding them, this could have caused the injectors to fire, weather they were suppose to or not.
if the injectors are switched by grounding.
I also have a 94 SLS with 228K with a white smoke glitch. I recently purchased it from an individual. He had it for 4 years & most all the maintenance was done at the dealer. He bought it with 144K on it. He told me about the morning white smoke (smells normal - no sweet smell). Haven't made any of the above recommended checks yet. After starting in the morning everything is fine for about 3 - 5 minutes then the heavy white smoke starts up. Prior to the white smoke it sounds like the engine takes on a load (similar to ac kicking on) then the smoke kicks in for about 5 minutes & then it starts to go away & soon after there is just a wisp out the tail pipe. Any additional suggestions on what the problem might be? Thanks.
It may be the fuel pressure regulator leaking fuel into the intake manifold and it takes awhile after a start to clear it out.
The 94 has the large plenum style intake manifold. The silver top cover is actually the functional cover of the intake manifold. Take the perimeter row of screws out of the cover (leave the center, recessed screws in place) and lift the cover off. The fuel pressure regulator is the small canister shaped device near the throttle body end. Turn on the key to pressurize the fuel system (do NOT start, just turn the key to on) and watch the vacuum nipple for any sign of fuel leakage. There should be none. The FPR is actually inside the intake in this setup so any leaking fuel drops to the bottom of the intake and takes awhile to be pulled out as the engine runs.
I pulled the top cover off yesterday & it has a bit of moisture/sweat looking farnish color through out (gas). I didn't notice a line connected to the FPR nipple (?). I cleaned off the top surface of the FPR & turned the key to the on position & noticed a little/slight wetness below the nipple, but nothing coming out of the nipple end. The fuel rack is very difficult to unlock from the clips (didn't want to break the plastic). Going to attempt the rack injector removal again tomorrow to see if the injectors are leaking. Is it better to replace a bad injector or rebuild (if possible). $63.00 a piece at Autozone. Appreciate any advice on this situation. Thanks.
Trying to remove the fuel rail to check injectors/FPR for leakage & the right front corner will not come loose at what looks like a coil with wires coming out of it. All other areas are free. Using this site to determine the white smoke problem. Thanks for any help.