Technical Seicento Kangarooing once warmed-up?

[pachadwick1]

Hi please can anyone suggest a solution?
My Sporting SPI motor runs fine until warmed-up when it starts kangarooing.

The engine ignition seems to cut out and return instantly whilst under acceleration, Tachometer fluctuates wildly but is OK under tick-over and light throttle. Like I said seems fine when cold but effectively unusable for any real journey.

What have I done to it recently to cause this?
1) Washed the engine bay
2) Put new NGK BCPR6E's gapped at 0.9mm
3) Adjusted the throttle stop to try and get 950 rpm to 900 (learnt since that I should not have tried).

So what next, any ideas where to look to fix this?

 

[rallycinq]

Put the throttle stop back where it was and change the O2 sensor.

Cheers

D

 

[fingers99]

I think 3 will be the issue. What was happening to get you to adjust the throttle stop? There may be something in the Sei Technical Manual (downloads library) to help you re-set it.

But, you may have residual damp in the ends of the ignition leads. Pull off one at a time and use WD40/Duck Oil, etc.

As rallycinq says, the lambda is implicated as it does it only once warmed up. You might try WD 40 on the lambda plug, first (the connector, usually on a plate on the bottom of the throttle body).

 

[pachadwick1]

Thanks guys, I noted in another thread how the plastic lead separators can harbour moisture, I'll give them all a wipe and a spray. Then I'l try and recover the throttle stop exact alignment. Then I'll look at the Lambda, that could easily have got some "rain".

Regards Paul

 

[pachadwick1]

Well, that must be the quickest fix ever. Went out with my list in the drizzle and a head torch. Checked the plugs and leads, freed them from the plastic guides. Then disconnected the battery to "zero" the ecu. I wound the throttle stop screw back into the housing until the "fresh silver" screw threads were hidden and found an indicative directional groove in the head of the screw, the throttle cam was as well rested as I could judge given I'd lost all original registration.

Disconnected the throttle POT lead, reconnected the battery and set the IGN key to MAR. Haynes says this is part of registering the "NO POT" or zeroing the value in the ECU. Then switch IGN to STOP or off. Then reconnect the POT lead and move the IGN to MAR. I guess the ECU notices the POT and assumes it is ZERO position or dead stop.

Any way when I restarted the engine, idle was fixed and after warm-up it was still running fine. Fingers99, thanks for your solution steer. Barring another check tomorrow, I would say it's fixed. I might get another Lambda sensor anyway, they usually help performance and economy, can anyone recommend a brand on eBay, I usually favour Bosch but they cost more.

Many thanks Paul

 

[fingers99]

Glad you got it sorted. But it was Rallycinq who called it first.

You've still not said why you were fiddling with the throttle stop!

I'd be inclined not to change the lambda unless you have to. But if you do, the OE one is the one to get.

 

[pachadwick1]

Thanks, I was fiddling with the throttle stop because I felt it was ilding at 950 or 1000 instead of 900 however as I have learnt that is not something we can control! Thanks for the advice, I've been looking at Bosch lambda products at £50 ish.

 

[slugworth1987]

idle should drop to 900 once car is at full running temp just bellow 90*C for the 899 for 1.1 i assume the same