Just spent $2,000plus to get my new 73' XJ6 (automatic trans) to run right - major tune up, etc. Still takes a long time (10 minutes plus) to warm up the engine when starting it up with choke wide open). Once it's warmed enough (to shut choke off and let it idle on its own), the engine still sputters and doesn't sound smooth at all when I shift into Drive or Reverse.
My main question: When I'm stopped at a red light with the car in "Drive" (and brakes on of course), my engine idle sounds very rough like it wants to stall. However, if I shift into "Neutral" (while I'm waiting for the light to turn green), the idle evens out and sounds much much smoother. Any suggestions as to what this might be? Could it possibly be a Mass Air Flow Sensor issue? I'm not too mechanically inclined (as you probably figured out by now), and this is my first Classic Car, but is it possible this is an easy fix? Fingers crossed. Thanks for the thoughts/advice.
Joe

Submitted by jquinn@cambrid… on Thu, 02/25/2010 - 14:42

Thanks George. I'll have to get back to you re the Gas milage. However, my gut feel is that I'm not competing with the Prius by any stretch! As for the RPM,s while I'm warming it up I keeep the Choke wide open and it stay around 1100 RPMS, but will begin to drop if I don;t tap the gas pedal. Should I have to tap the gas pedal while I'm warming the engine up with thhe choke wide open? Somethign doesn;t sound right about that.

Also, just realized I was about dead empty on gas while I was having most of my problems the other day (my gas gage does not work - mecahanic said it will require a couple hundred to fix so I'm holding off until the Spring).

Lastly, with the gas (unknowingly) tank empty and trying to warm the engine, I noticed a trail of black spots on the garage floor right under the exhaust pipes. Put a cloth behind the pipe while the engine was running and saw black spots (oil?) spitting out of the exhaust pipes. Might this be another problem I'll have to deal with soon?

Thanks so much for your insight and advice.
Joe
215-791-0074 for more details

Submitted by SE98-32482CJ on Tue, 02/23/2010 - 15:38

Joe your car has no mass air flow sensor--the slow warm up sounds like a failed open thermostat. If the car idles well warm in P or N then it sounds like you may need the idle adjusted (up). One thing that would be helpful is what RPMs are you at at the various conditions--idle, idle in drive at stop. idle in park etc. The other bit of information is what sort of fuel consumption are you having/getting ---does the car run smoothe through the gears when driving?????

Submitted by bob5837@roadru… on Tue, 02/23/2010 - 14:08

I have a 1987 XJ6 with fuel injection and just had the engine completely rebuilt. It also idles rough at a stop light but runs fine otherwise. I too am curious if anyone has a "fix" for this.