Runs great but sounds a bit strange

[declanka]

Hi I have a 1990 2.2 Turbo I bought last year, its a great car in great condition and drives nicely. However as you are going through the gears (as you change) there is a fair amount of popping and farting mainly from the exhaust. I am no big mechanical expert but to me it sounds like some level of fuel burn after the exhaust manifold but I could be wrong. Do I need to do some tuning / servicing of the fuel system. Any suggestions what to look at or if its not a problem let me know. Thanks

[Sir Paolo]

I'd check the ex m/fold. It could be cracked or it could be working itself loose from the head.

[rogerch]

It sounds like a wastegate doing it's job, could be running rich on the over run.

Mine's pre Freescan but a 90 isn't so I'd be trying that analyse any issues.

[Bibs]

Which carb should he plug it into? Freescan is for EFI cars only.

Popping and banging is often due to air getting into the exhaust gases. Check the manifold/turbo and rest of the system.

[rogerch]

[ramjet]

Dunno where you got that, but I don't think it's correct.

http://www.lotusespritworld.com/EModels/Turbo.html

[rogerch]

On the contrary, you've posted a link to the specs of an 87.

[mattthesparks lotus esprit]

^{I’m no expert but if your car is carbed and has ever been to sj sports cars or Maidstone sports cars for a new exhaust then chances are its got a different type of exhaust, where they cut out a few of the silencers and went straight across causing popping and farting on shifting up or down, all you need to do is set the timing out but 15% and should cure this. Mine had this exact problem. Good Luck if not try and get your car over to Watford exotics and see sparky a genius!}

Edited August 3, 2012 by mattthesparks lotus esprit

[Whirlybird]

Ah, just got a new exhaust and now its popping every now and then.

I did wonder why.

[Mike6]

Carb turbos have a habit of popping and banging but as has been stated its possible the exhaust manifold is cracked or needs retightning to the head. I would check timing first and then balance carbs and mixture.

You may in the end just have to live with it and enjoy the admiring glances.

Sorry meant to add that if the car has a newer stainless steel exhaust with bigger bore, less baffles etc then this may be the reason. However its a simple job to check the time and balance the carbs