It is probably better to give you the story of what I have done.

 

I have done a rebuild on my 91TT with 555CC injectors, lightend pullie, greddy intercoolers, new loom, new O2 and water sensors, PCV hoses and valves and DoolZ POP with 1 APEXi filters.

 

I got a chip from some one who dabbles with making his own map. The chip is said to be for a dual pop 555cc setup.

 

The car starts but wont idle. When the dual pop was on it would struggle at 500rpm or so and the idle adjuster screw didnt make any difference. A few days alter it would get worse and the car would not idle. On starting it would rev to about 1200rpm for about 3-4 seconds, start to come down and stuggle around 300-400rpm before stalling. Suspecting the chip, I put the single POP setup back on.

 

The car now starts and idles about 600-700rpm but again the idle screw adjuster makes no difference. The idle is a little rough but it will idle for about 15 seconds or so and the the revs drop and nearly stalls and rises back. It does that 2 or 3 times and the idles around the 700rpm for about 15 seconds before the revs drop again.

 

Another strange symptom, is the left hand exhaust gas is warm while the right side exhaust gas is cold.

 

ECU check is clear, there are no air leaks, only a slight one by the EGR (I knew I should have got rid of it when I had the chance).

 

The engine over 1000rpm is perfectly smooth and I have raced the engine a few times, but the revs do drop a lot when I first press the accelerator.

 

Can any one help?

Does any one know what the symptoms are for having a wrong chip installed?

Whats causing the revs to drop when I press the accelerator?

Does it sound like the idle adjuster is not working?

 

Thanks,

Stuart

the chip isnt for a JWT twin pop is it?

 

i believe the Doolz one is different at it has the balance built into the design itself, rather than additional hoses like the JWT has.

the chip isnt for a JWT twin pop is it?

 

i believe the Doolz one is different at it has the balance built into the design itself, rather than additional hoses like the JWT has.

 

That's my understanding too (from reading copious posts over on TTnet)

 

Can any one help?

Does any one know what the symptoms are for having a wrong chip installed?

Whats causing the revs to drop when I press the accelerator?

Does it sound like the idle adjuster is not working?

 

I can't think of any reason for the idle adjuster to stop working - it's the simplest mechanical device you can think of (a screw that adjusts an air leak) - but.. silly question time - you are disconnecting the IACV connector when you adjust the idle, right? I'm sure you are, but it can't hurt to ask :)

 

It does sound very much like the chip is wrong for the intake - a single POP chip won't work with a Doolz AFAIK and neither will a 'normal' dual POP chip (i.e. the JWT style chip)..

 

Revs dropping when you hit the accellerator - is the TPS adjusted OK? Vacuum leak perhaps.. erm.. *thinks* I'm sure someone will add some more later..

So will a Dual JWT chip work with a Doolz?

I cant see why not.

The only real difference with the DoolZ and the JWT twin pop is the DoolZ balances its self while the JWT you have to plumb lines from the recirc to the idle valve.

 

Yes I have disconected the idle valve before attempting adjusting and I tried it with out too.

 

I have done a air leak test with Vijays boost leak tester and there is only a slight leak on the EGR, that's it.

 

The TPS has been set to about 0.43 which is not perfect but shouldnt make much difference. It is meant to be 0.4 but I heard setting it a little higher to 0.44 is better.

Sorting out the idle can be quite tricky with 555's.

I usually raise the speed to about 850rpm (in the ECU so it's still controlled). Biggest factor is usually ECU correction factor being off.

Should be able to sort it out if you want to come over some time.