free hit
Loss of power, TURBO SE 1990 - Engine/Ancilliaries - The Lotus Forums - Official Lotus Community Partner Jump to content


Loss of power, TURBO SE 1990


Recommended Posts

Hello everyone !

Last time i took my baby out for a drive, something strange happened.

I drove the car slow first during the first minutes so that everything's at the right temp/pressure.

Then i started to kick in but there's a strange loss of power !

- Engine looks running normal at idle.

- Turbo comes in too late (4'500/5'000 rpm)

- Turbo boost hardly reaches 0.6 bar, and i have to rev to 7000rpm to get 0.8 bar

- Behaves like an atmo car til 4-5000 rpm

What can be the cause of this?

The car has 74'000 km. The cam belt was replaced at 71'000 km in june 2006.

Is it possible that the timing belt may have "slipped" one tooth ?

(but would the engine then rev at full 7000rpm, and sound normal at idle?)

Turbo ripped? But would it even work then ?

Any air intake before the turbo ?

I would need you opinion, impression is that instead of working between 3000/7000rpm, the turbo range moved into 5000/7000rpm and the car lacks lots of power even with turbo in

Thanks for your help

(No good tech around here, so i'm just asking before driving few hundred kms to Kumschick !)


Link to comment
Share on other sites

Upgrade today to remove Google ads and support TLF.
  • Replies 5
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

If there is low boost, it could be a couple of things. Firstly, the ECU could be reducing boost because it's picking up knocking.

Another problem could be a broken or sloppy spring in the wastegate actuator, allowing too much exhaust gas to bypass the turbo. you can check that by trying to move the rod by hand, and see if it moves. It shouldn't do. You could also remove the pipe going to the actuator and very VERY gently drive it to see what the boost pressure does. Without the actuator actuating, it should run up to insane levels of boost very quickly. I would check this last though. It's not a good thing to do.

I'm sure other people will post advice. In the meantime, I'd avoid thrashing it until you've found out what's up. If the ECU is limiting the boost, there will be a reason for it that needs fixing.

If your belts had slipped, I think you'd have more serious problems. It doesn't take much before the valves start pinging into each other. you can check that quickly with a timing light. There are two dots on the pulleys that will line up when you are at the right setting.. It's in the manual somewhere as I can't remember what it is.

Having read your post again, if you are lacking power generally, there are obviousley a load of reasons for this. Ignition, injectiors blocked, low compression in the engine.. Be cautious and drive carefully, or better, not at all, until you find the solution.

Edited by Glyn Harper
Link to comment
Share on other sites

Main concern was the timing belt slip. But i've driven +3'000 km since. The problem happened yesterday. The car was working fine until then !

Thanks for your help Glyn. Waiting for other advice too maybe ?

PS: i've also read my post again, sorry for confusion, in the atmo working range of the engine, i don't think i lose any power.

The loss is due to lack of turbo boost mainly. I was following a Ferrari 308 carb. & Maserati 222 with quite some ease without turbo (or low turbo boost).

Edited by Alireza
Link to comment
Share on other sites

  • 1 month later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Upgrade today to remove Google ads and support TLF.

  • Create New...

Important Information

We use cookies to enhance your browsing experience, serve personalized ads or content, and analyze our traffic. By clicking " I Accept ", you consent to our use of cookies. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.