Hi all, first off id like to thank everybody for providing me with various hints for my felicia over the last few months, ave been a regular browser, and decided to register.

I have some problems with my felicia 1.3 MPi (1998) 136 engine. It seems as though the throttle position sensor (or something related) has failed, as it contantly "hunts" whn idling, often stall when idling.

When driving, if any significant load is placed on the engine it will rev to the limit but has no power, then subsecuently stalls again, making it dangerous to drive.

I have replaced the CTS and Hall effect sensor (the one on the flywheel), which have had no effect. Copnsulting haynes and this forum seems to indicate the TPS is at fault. I have removed the throttle cover when the idle is hunting and have seen the throttle unut (where the cable attaches) move in time with the "hunting" and then completely close just before the engine stalls. CAble tension is correct.

I called IML for a new replacement part, they quoted almost

it seems that the throttle body failing is quite common, but i would also have a look at the map sensor because this is the sensor which tells the ecu how much load the engine is under.

it seems that the throttle body failing is quite common, but i would also have a look at the map sensor because this is the sensor which tells the ecu how much load the engine is under.

where is the map sensor? is it the one just behind the throttle body directly attached to the far rear of the inlet manifold? (3/4/5 ish pin plug?) can it be seperately removed?

Thats the one. Yes it does just unbolt.

Tricky thing is when replaced the throttle body will need to be adapted with diagnostic equipment. (this could be all yours needs).

i checked the map sensor, all was ok/. I have not ordered the replacement throttle body yet.

What i have done is removed the metal cap off the old throttle body (the part that coveres all the actuators / sensors and put it back on the car. I can now see that when the engine speed changes at idle (the hunting) the stepper motor is completely closing the butterfly valve and therefore choking the engine. It would definately seem that this is the right part to replace?

The potentiometer tracks were dirty, a little electrical contact cleaner seemed to solve the hunting at full load, but i presume the motor is only active at idle.

Any further thoughts would be appreciated!

It's an expensive part to buy with any reasonable life guarantee. One for a few quid from a scrapper is likely to be either faulty, or on its last legs, unless you get one from a crashed car which has had it replaced recently.

I got one from here but be warned that the Peirburg one for the 1.3 isn't the part shown, and it costs about UKP 225 with delivery, AND they want the old one back using the pre-paid label, or you get surcharged about UKP 70.

In an ideal world you need to get the "basic settings" performed on the engine management by a Skoda dealer too, as mentioned above.

It's one of those "how long are we going to keep this thing?" moments.

since the unit is broken anyway, i thought id have a bit of a play. After taking the metal cap off again i cut the power rail going to the stepper motor, then following a suggestion from another similar thread i spliced the yellow wire into the yellow/black.

and guess what.....

RUNS LIKE A CHARM!!!!!!! idle a little rough but seems to have loads more power, gained 10mph in top speed as well!.

trick is to bend the return control spring so it returns a little lower.

It seemed that because my stepper motor control was a little off, it was keeping the butterfly valve in just the right place to *almost* choke the engine. the ecu then powered the motor to open it a little more, and when it detected better engine speed it released the motor again, going back to its choking point. hence the "hunting" i was talking about.

Will definately get the new unit though, see how it fares with a complete unit. interesting..

ill let you guys know

. After taking the metal cap off again i cut the power rail going to the stepper motor' date=' then following a suggestion from another similar thread i spliced the yellow wire into the yellow/black.

and guess what.....

RUNS LIKE A CHARM!!!!!!! idle a little rough but seems to have loads more power, gained 10mph in top speed as well!.

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wasn't that me that suggested that?? i can't remember but it might have been. i'm glad it worked anyway.

wasn't that me that suggested that?? i can't remember but it might have been. i'm glad it worked anyway.

im fairly sure it was you!. still going ok? god knows what signals the ECU is getting, fuel consumption does not seem to be affected!