Page 2 of 8 FirstFirst 1234 ... LastLast
Results 11 to 20 of 74

Thread: Getting atrocious mileage?

  1. #11
    Join Date
    May 2018
    Location
    Albany, NY
    Posts
    193

    Default

    Quote Originally Posted by Croc View Post
    What is that stuff on the plugs? Mud?
    I think so. Same stuff that's in the channel. I wiped it off

    Some of the tips looks much smaller than the others (a little hard to tell in pictures)

    Might just replace all while I'm at it. Any recommendations? Same ones? They are motorcraft platinum now.

    Doubt it's the issue but can't hurt.
    2001 Caterham Superlight R

  2. #12
    Join Date
    Feb 2009
    Location
    The Frozen Northeast
    Posts
    485

    Default

    Did you have water sitting on top of the head over the winter?
    I’ve had water on top of my engine after getting caught out in the rain

  3. #13
    Join Date
    May 2018
    Location
    Albany, NY
    Posts
    193

    Default

    Quote Originally Posted by wemtd View Post
    Did you have water sitting on top of the head over the winter?
    I’ve had water on top of my engine after getting caught out in the rain
    This car has never seen rain during my ownership and hasn't been used much in the last 10 + years in California. I doubt it saw rain back then too.


    What mileage should I expect with highway driving, 6spd, Jenveys on Zetec? Even a ballpark. 20?
    2001 Caterham Superlight R

  4. #14
    Join Date
    Feb 2016
    Location
    Central WA
    Posts
    124

    Default

    I find mileage depends on how you drive it. I have a 2 liter Zetec, ITBs, Emerald ECU, stage 3 cam,and I can go through half the tank in 20 minutes at a track day, or about 5 gallons. If I drive it in a less spirited manner, I might get 20 MPG, but what is the point of driving it if I just putt around? So, the 20 mpg is more theoretical than something I've verified.
    2003 Birkin

  5. #15
    Join Date
    May 2018
    Location
    Albany, NY
    Posts
    193

    Default

    Quote Originally Posted by Alfonse View Post
    I find mileage depends on how you drive it. I have a 2 liter Zetec, ITBs, Emerald ECU, stage 3 cam,and I can go through half the tank in 20 minutes at a track day, or about 5 gallons. If I drive it in a less spirited manner, I might get 20 MPG, but what is the point of driving it if I just putt around? So, the 20 mpg is more theoretical than something I've verified.
    Alfonse, thank you for the reply.

    I understand that it will vary depending on how you drive it, but if I'm getting ~8/10 mpg on just highway and putting around means I'll be getting 2/3 mpg on a track day I'll be running out of gas very quickly and there is a serious issue that I need to address.

    Trust me, I'm not bringing this up from the economic perspective/concern.
    2001 Caterham Superlight R

  6. #16
    Join Date
    Aug 2006
    Location
    College Park, MD
    Posts
    558

    Default

    I don't like the look of all that gunk in the threads of the #1 plug. Even if there's all manor of crap in the "tunnel" for the plug the threads themselves should be pretty clean having spent their life engaged in the head. Sure, some gunk may brush into them on the way out, but they look pretty uniformly covered. Did that plug feel right when you loosened it and threaded it out?

    Dave

    Edit: sorry, no wisdom on what mileage you should expect, but 10 does sound low for street driving.

  7. #17
    Join Date
    Feb 2009
    Location
    NYC
    Posts
    4,403

    Default

    I was thinking overnight (don't look shocked!) - I wonder if that gunk in the threads is coppaslip/copper grease as the prior owner was dealing with a sticky thread? Looks like it was applied at time of inserting the plugs and has a similar consistency after high heat application. I would feel a lot better if thats what it was - since it should not hurt the engine inner in miniscule trace amounts although you probably dropped more than that into the cylinder? If it were mud gunk then it should have dried up by now (and be easy to vacuum out). If it is still wet consistency then that will confirm it is a grease of some type.

    I think all would agree the street driving mileage is lower than you would reasonably expect. So your question is a very valid one to solve.

    So it is probably time for a retune on the dyno but before then - thinking my way through the air, fuel, spark equation:


    • I would change those plugs to a heat spec suitable for your engine. Don't assume what spark plugs you have in there are correct - start from scratch and check as you may have the wrong plugs currently and that is part of your problem.
    • Any evidence of piston scorching or carbon build up in each cylinder? Usually the signs of lean or rich running appear visible from a cylinder inspection through the spark plug hole.
    • Does your exhaust tip look black with carbon deposits? If it is clean then did you clean it and was it black before?
    • Any evidence of water or other contamination of the ECU?



    Edited to add: Still not convinced that crud on the plugs is not dirt/mud. Will be interested to hear if it dried out by now
    Last edited by Croc; 05-10-2019 at 03:51 AM.
    Mike
    2010 Caterham CSR with Cosworth 2.3 Duratec
    2018 Caterham 420R with 2L Duratec 210hp at Donington UK
    1975 BMW CSL Group 4 (restoration - engine and dry sump install time)
    1977 Holden Torana "A9X" (awaiting restoration)
    1985 Holden Commodore Group A (restoration - engine rebuild)
    1982 Ferrari 400i (will repaint to original color in 2020)
    1965 Ford Mustang Fastback "Holman Moody"
    1992 Ford Escort RS Cosworth WRC (fettling after long period of storage)
    1990 Range Rover 2 door Classic

  8. #18
    Join Date
    Oct 2006
    Location
    South Lyon Michigan
    Posts
    203

    Default

    If you are using that much gas, you should see exhaust smoke and smell raw gas. You could get better mileage with a BBC. I get 22 MPG on the back roads and 30 MPG at 75 on the expressway. Dave W

  9. #19
    Join Date
    Nov 2007
    Location
    Ambler, PA
    Posts
    981

    Default

    Never Seize on the plug threads on a aluminum head is what your supposed to do. It also collects dirt.. a few things to think about. New plugs , fresh gas, and maybe the O2 sender is crapped up or not working. Itís this how it ran when you got it??
    Superformance S1 # 47

  10. #20
    Join Date
    Jul 2013
    Posts
    271

    Default

    Croc quote: "I was thinking overnight (don't look shocked!)"

    Somehow I am not shocked that you think more clearly asleep than awake. That explains a lot.

    Cheers.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •