[Mk2] [Turbo] Ruff idle and jerky exceleration

[Thethorne]

Hi all this is my first post. I've recently bought myself a rev4 turbo but I'm having a few problems that I'm hoping someone can help me with. When I start the car it idles very ruff at about 600rpm once warm she sometimes idles fine but more often than not she runs at 600rom. Under exceleraration in first and second she pulls hard but in any hear higher than this at about 2500-3500rpm she holds back. If I keep my foot down for about 10 seconds she does begin to pick up and go again. I've replaced the dizzy cap and arm ht leads and plugs which hasn't helped any advice would be much appreciated. Thank in advance.
Thethorne

[rev3gtturbo]

Welcome to the forum.

Not sure how familiar you are with these old turbo cars.
Has the car been modified?

They run a bit rough if not using super unleaded fuel (supermarket super is all it needs) but you have other problems.
They dont really use the turbo in 1st/2nd gear which might explain why you see a difference trying to accelerate in the higher gears - check the engine bay hoses for splits, cracks and loose fittings.
it will also hold back if the engine is not up to temperature - Temperature gauge should have settled just under half way up before doing any hard acceleration.

What does it idle at when warm? (with the lights and heater and other electric items turned off)

Also check the ECU for fault codes - see
http://www.imoc.co.uk/forums/viewtopic.php?t=123155

IMOC trader Pacific Works are not far from you. You could take it to them for a check over. Sounds like the stuff they could sort out.
http://www.pacific-works.co.uk/

Good luck with the car. Hope you start enjoying the turbo performance soon!

[Thethorne]

Hi thanks for the reply I've checked for boost leaks and I'm running super unleaded. The problem seems to be getting worse under any load at any temperature the car just doesn't seem to pull as it should. It just splutters and misfires and then gradually pulls through it and even when it's hot it still has a very poor idle you can feel the engine shacking inside the car.

[rev3gtturbo]

Did you check the ECU for fault codes?

[Thethorne]

I've tried but it doesn't seem to work I've followed the guide on how to do it but I can't seem to even get the engine light to flash it might have something to do with there being lots of vasaline in there maybe.

[MartinF]

Does the engine light come on when you start the car?

[markstevieandmads]

Weak spark?

Try checking the coil. These crack and let in moisture which tends to mess them up as you can imagine.

[Thethorne]

Hi thanks everyone for the reply the engine light does come on when the ignition is switched on and also I will try check the coil at the weekend the problem seems to be getting worse as it actually cut out for the first time today.

[rev3gtturbo]

I've tried but it doesn't seem to work I've followed the guide on how to do it but I can't seem to even get the engine light to flash it might have something to do with there being lots of vasaline in there maybe.

I think the grease in there is stop the connector corroding?

You might need to remove a bit of the grease to get a proper contact when you check the ECU for fault codes.

If you were doing it right, and there are no flashes then there are no ECU fault codes (as you have confirmed the dash bulb for the engine light is working when you normally switch the ignition on).

[rev3gtturbo]

... and also I will try check the coil at the weekend the problem seems to be getting worse as it actually cut out for the first time today.

When you replaced the HT leads, did you use genuine Toyota leads? (Some aftermarket ones dont quite fit properly for some reason and can cause weird problems).

While the car is still drivable why not just take it to Pacific Works?

They know these cars inside out and I reckon they could diagnose it quite quickly. They have lots of spares that can be swapped over to help diagnosis.

[tehdub]

Hi Matt,

Also in reading, so might be able to pop over if you need a hand. Not an expert but done a few bits and pieces before.

Without stating the obvious, its either fueling or spark. If you've done the basics, and checked boost leaks, HT leads, Dizzy cap and arm, I'd check the base timing, in case its out, and giving you too much or too little advance.

http://www.imoc.co.uk/technical/howto/mk2ttiming.htm

And I'd check the o2 sensor as well, as if it fails it won't necessarily cause an ECU code.

http://www.mr2.com/TEXT/O2_Sensor.html

Ignition module is a good shout as above.

To me tho, it sounds like fuel cut or boost protection. Would help if you stated revision and mods.

[JAAASH]

If you were doing it right, and there are no flashes then there are no ECU fault codes

Incorrect. If you have no fault codes the engine light will continuously flash at half second intervals.