Hi folks
New to the forum I'm posting this from iPod no comp at moment.

Any idea why my turbo would come in too early?

I can't seem to rev over 5k before the limited kicks in

Driving a 97 cat

I have no idea why but the turbo starts about 2k to the limiter can't get above 80 mph

Thanks in advance
Coops

 

ur speedo working ok

 

Hi yes that is fine car runs perfectly otherwise. Just very strange when I put my foot down the power is there then very abrupt almost stop till next gear. Very hard to explain it's as if the engine stops next gear same at about 4-5k revs top gear bottomed out at 85mph foot off accelerator then it went ok till turbo came in again

Very confusing
Coops

 

Is there a boost controller fitted?
Is the CEL coming on?
Can you go above 85mph without going WOT?

 

Sounds like overboosting. You got a pipe off? (small ones to actuator). That would alow the turbo to boost until the engine decided things weren't quite right and cut the fuel.

I think.

 

Sound like it's boosting too much and hitting fuel cut.

Are there any mods that the car hasn't been mapped for?

 

Hi,
No check engine light, i have a GReddy boost gauge fitted and have no idea how to set it it's at 0.5 at the moment.
Had a look for any pipes off the actuator but don't look like it, there is a small brass adjusting screw inserted between two thin rubber pipes at the actuator area(no idea why)
If i take it easy and dont use the turbo ie, very very gently on throttle it picks up above 85mph but if i get to top gear around 50mph then put pedal to floor the limiter cuts in very fast then again if i take foot off pedal and gently apply it's fine..

Sounds like a overboost problem but what are the main culprits?

I'm unsure of any engine mods that the car aint been mapped for.

As far as i'm aware it's just a induction kit, boost gauge, turbo timer, SS exhaust thats pretty much it.

Thanks for the replies so far folks

Coops

 

Its that brass screw. Its fooling the system into boosting more, screw it in more and try again. Or if you can, clamp the pipe so no way any pressure can get through. Drive it again and it wont really boost but will prove if its that.

 

Sounds like it's fitted with a crude manual boost controller, close it a bit and see if it makes any difference

 

i found a split in a wee blue rubber pipe sorted that, still done it..

screwed that bolt right in and like you said JB it sorted it with little or no boost.


Can i just stick a t-piece in place of that? would that sort it do you reckon?

Cheers
Coops

 

Like Pete said, it's a crude manual boost controller. The screw restricts the pressure, so it fools the system into thinking it isn't boosting, whereas it's actually boosting fine.

What you need to do is get it taken off and the std restrictor put back in (there is a brass one in one of those small pipes). And then get it checked by a good tuning company to see what has or hasn't been done.

Or, if you want to take some risk. Unscrew the screw a bit, go for a drive, see if it happens. If it doesn't, then unscrew some more, repeat till it cuts and then screw it back in a bit. But if you do this there is a good chance that it will be running very very lean without a remap (very bad for a Scooby engine).

Best is take it to a known, good, tuner and ask them to take a look and tell you what they think.

Take a pic of it and post it up so I can see where the screw is fitted in the pipes, but I don't think a T piece will help, you need to have some restriction in the pipe for it to work right.

 

coops

 

Yep, Crude manual boost controller. Get to a scrappy and get a replacement pipe with restrictor in place and replace the pipe.

Best advice is once the standard pipe is back in place is to get it checked out by a competant mapper/tunning company to check it's running fine, especially your AFR's.

 

dead on cheers mate. looked to be a bit scrappy as just floating down with no brackets or security.

now i just need to find a good tuner in the midlands...

coops

 

Where in the Midlands? Near Stafford? Chevron Motorsport get my vote every time. But then I am biased.

 

live in redditch cant seem to find one one nearby