rough running

[steve.m]

Hi,
Could anyone help shed some light on my problem.
I have recently ( 1 week ago ) purchased a 91 elan se. The latest in a long line of Lotuses over the years. The car has had a BBR conversion carried out in the past. Anyway I purchased the car which ran great on the test drive. I then drove it 670 miles home to Scotland. Again the car ran great. I have driven it every day since with no faults. On Sunday I took my son to an American car show and did a 100 mile round trip again with the car running great. I parked the car in my garage and went out the next day. When I tried to start the car it did start but sounded really rough. When I tried to rev it it wouldn't rev and lots of black smoke was coming out of the exhaust, it wouldn't clear. I removed the spark plugs and they were dry and black with soot. I put in new plugs, same problem. I managed to keep starting the car and eventually it cleared and I ran it for a few miles and stopped it a few times. It seemed ok and I left it overnight. Went out today and the problem is back. Rough running, wont rev and loads of black smoke. I did a compression check, all cylinders are 170 - 175 psi. I phoned the previous owner who said he never had this problem and the car has run great for well over 1000 miles for me before this problem. Any help and advise you can give me would be greatly appreciated. P.S as an afterthought I have also noticed the speedo seems to be a rough guide as to actual speed. I reckon I am doing 70 when reading 90 etc, is this common and does anyone know the fix for this.
Best regards
Steve Manett

[Monty]

Steve, there`s a few nutters in scotland who own a few M100 may help u out.

Sounds like u`ve got some kinda sensor failure or the timing is way out. Are u getting the check engine light on the dash?

If so try the paperclip test look here:-
http://lotuselancentral.com/repair/aldl.htm

[John_W]

Steve,
Where in Scotland? ... sounds like you might be in the NE. If so, we could arrange an ElanScan session to see if it's a sensor problem.

Do you have a "check engine light" on? (The orange light on the bottom right of the instrument cluster). If so check the error codes as described in the "paperclip" test elsewhere.

Check no hoses have fallen off the plenum chamber. Check the air filter isn't blocked with crud.

Good luck,
John

[M100 TWO]

when you turn the ignition on leave for 10 seconds before engaging starter this will allow the ecu to evaluate all sensors

[Ashaman]

Maybe the fuel pressure regulator?

This is in general, not elan specific, but I would assume it is no different...

They can rupture and let the full 90 psi (or whatever the pump is capable of) directly to the injectors instead of the normal/regulated 40 whatever.

When that happens you will have all the symptoms you have described accompanied by a strong unburned fuel smell.

Could be other things of course, but it sounds pretty drastic so the FPR gets my best guess

[steve.m]

Thank's for all the replies guys. With help like this I reckon when I get home from my stint offshore the elan will be back and running fine in no time. Just surfed into the site by accident, glad I did.

Steve

[steve.m]

Hi everyone,
Arrived home from offshore yesterday and went to try and start my elan. I went for the easiest suggestion first and turned the ignition on and waited about 10 seconds before trying to start the car. Success, car fired up first turn of the key straight onto idle on all four cylinders. Car is running spot on. Thank's again for all the help and it is nice to see that sometimes the easy fix does work.

Cheers
Steve