free hit
counters
Late turbo engagement - Induction/Turbo/Manifold/Exhaust - The Lotus Forums Jump to content
Sign in to follow this  
rusty55125

Late turbo engagement

Recommended Posts

Late turbo engagement.

I was driving my 98Esprit around town yesterday and noticed that when I got on it a little, the turbos didn

Share this post


Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.

Do you know what boost you were actually seeing? Did it boost fully or were you actually getting lower boost, as well as later building of boost?

Of course, it could just be the effect of warmer weather and the impression of less power or the ECU trying to cool in the inlet air.

Let us know what you discover when you have a look around.

Cheers,

Mike S


1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

Share this post


Link to post
Share on other sites

When the turbo kicks in it's very strong but just late. I don't have a pressure meter to know that the boost pressure is when it does kick in.

Scott

Share this post


Link to post
Share on other sites

Does it feel as though its hesitating and then your boost comes in suddenly?

That's the problem I had (and it seems to be coming back intermittently again), last time I had the waste gates changed. I also needed a new cat as it seems I was dumping unburnt fuel and that wrecked the cat.

If it might be the same, I'd get it looked at quick rather than risk the cats.

Jeff H

Share this post


Link to post
Share on other sites

Do you know what ended up being the problem? It does appear to be a little hesitant when I punch it and then the turbos come on strong. Could be the same thing. I will have to go over it this weekend but if you can give some direction I would appreciate it.

Scott

Share this post


Link to post
Share on other sites

Well, still nothing as to why I have a bad hesitation and a late boost engagement. When I let the car go a little ( city highways), I can get to the higher speeds very quickly. The top end it appears to be fine once I get to 4500rpm

Share this post


Link to post
Share on other sites

Well starting with the ECU fault history must be a good first step. I have a turbo boost gauge fitted which if nothing else confirms the linear build of boost. It does sound to me turbo related. :blush:

Rgds

B

Share this post


Link to post
Share on other sites

Well I finally got my software and I got three codes out of it. P0447, P0420, and P0430. The last two are for a O2 sensor efficiency of the catalyst, one for the left, the other for the right bank. I suggests that the efficiency of the catalyst is bad. Is there any other way to check if the Cat's are bad? Could it be the sensors? The top end of the care doesn't appear to be lagging, so how could it be there is a restriction. What else should I be checking?

If I need new Cat's, where is the best place?

Scott

Share this post


Link to post
Share on other sites

you can inspect your catalytic converters by a quick look inside the o2-sensor mounting points. Use an fiber optical tool, some made of full plastic and are cheap to buy. If you see some loose parts blocking the rest of the intact monolith than you have a problem !

The aftermarket offers an wide range of SS, or ordinary catalysts. You can have an ready to fit re-fabrication (PUK, R&B, Superdave, Lotus cars, and so on -or more simply : you use universal (round type) cats from the aftermarket with the right diameter and fit them into the original housings.

Edited by G

*********************************************************************

to name the things if I see them, that's what I call integrity..

*********************************************************************

Share this post


Link to post
Share on other sites

I have a great supplier of custom mufflers and exhaust systems very close to me. I used them for a Austin Healy Kit car I have and they were very reasonable. If I have to have them put some new Cat's in, what flow should I be telling him? I happen to have a fiber optic tool that I will try to look inside the O2 sensor tonight and see if there is anything of interest.

Scott

Share this post


Link to post
Share on other sites
I happen to have a fiber optic tool that I will try to look inside the O2 sensor tonight ...
God, there's 2 of you!

Cats falling to bits are quite common, especially the factory jobbies - but I think you'd get slightly different symptons, namely a very strangled car after about 4,500 rpm when it's trying to pump lots of gas whereas low down would be less of a problem.

I think it's unlikely to be the boost solenoid, the boost solenoid pulses open and shut rapidly to enable the ECU to maintain the pressure it wants at the wastegate. If this was permanantly open, or there was a leak then the car would produce much higher than normal boost - to the degree where it could potentially damage the engine, but low down boost would be largely unaffected. Whereas if the boost solenoid was permanantly shut then the car would only make the boost as per the ratings of the springs in the wastegate about 5/6 psi off the top of my head. In theory it would still spin up just as quick{ish}, but would most likely feel a bit flat top end.

I think for me the first place I'd check is the wastegate solenoids themselves, the factory one's do rust and fall to bits at which point they will flap around, low down your car will make no boost at all but may pick up as enough gas is being pushed through such that all of it cannot be blead off.

Check for leaks around exhuast manifolds etc this will blead off exhaust gasses before they make it to the turbo, and will produce rattly sounds.

I think after that I'd wait until you get your OBDII up and running, you'll have a much better idea of what's going on. Short of a failed turbo, i think you're probably going to be looking at a wonky sensor confusing the car - front O2 sensors, MAP sensor, coolant temp sensor or throttle position sensor.

hope some of that helps.


Hey, can anyone smell fuel?????

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...