Hi folks

I have a intermittent problem with my 1994 Skoda Favorit GLXi. Its cutting out while driving, sometimes i manage to keep the car going by flooring the pedal and keeping it in gear. When i cant keep it going it stalls and wont start again since the fuel pump isnt getting any power. By moving the car and leaving it for some hours i can start it again and drive on like nothing happened. What and where is the fault?

Things i replaced:

Fuel pump

Fuel filter

Regards Brogard

hi brogard, check the connection to the crank sensor on top of the gearbox bellhousing first... on the fuel injected cars the fuel pump relay is controlled by the ecu, it earths the relay to switch it on, that relay also powers the ignition coil/amplifier, it might be a lazy relay..

when it cuts out do you know if you are getting a spark at all when you are trying to restart the engine?

Hi tom

I found a small leak on the cooling hose above the gearbox and it seemed to be leaking liquid on the crank sensor, so i suspect that is the cause?

I havent checked if i get a spark when the engine cuts out, will do that next time it occurs.

Btw, thanks for a fast reply

Update: The relay isnt the problem and the cranksensor is clean, can it be the ignition coil? I dont think i get a spark when i try to restart after it cuts?

Check all electrical contacts in the engine bay.

Disconnect the (-) cable from the battery.

Open each connector, spray some WD-40 in or any other contact spray, let it dry, connect it back.

Don't forget earth connections too.

While it may seem an overkill advice, old cars need such cleaning anyway.

Edited 11 March, 201313 yr by adurer

Update: I checked all electrical contacts in the engine bay, cleaned them and gave them some contactspray. The multiplug to the fuelinjector was oily but it is cleaned now. (thanks for the tip Adurer) Now the problem has changed, the engine starts rigth away, but is idling very erractic and then it cuts out. But now i can restart the engine rigth after it cuts out only to encounter the erractic idling and then it cuts out again? I am complety lost in how to fix it and where the problem is?

Can you do an OBD reading?

Or try a throttle body cleaning, new gasket, reset.

Edited 12 March, 201313 yr by adurer

I've cleaned the throttlebody the best i could. But now i can run the car for 20-30 minutes before its starts to stall. If i driven it for 20 minutes without any problems, i park the car, wait 5 minutes and then when i try to start it again it wont start. But if i unplug the multiplug fuel air breather thing behind the ecu it can start, but idles radically. Do i need to get an OBD reading?

That suggests that the sensor you're unplugging is the problem. Before spending out any money, do you have a mate that could lend you the sensor from his car to try a swap?

"multiplug fuel air breather thing" ??

"idles radically"??

Did you reset TB after cleaning? See how in document below.

http://www.ms-motor-...0091_en_web.pdf

Edited 20 March, 201313 yr by adurer

Im getting it to a guy i know with a OBD cable this weekend. But ill try the TB reset, thanks for the guide

"multiplug fuel air breather thing" ??

I got it. You probably mean the activated charcoal filter solenoid valve.

Anyways, you have to make distinction between real fault codes and sporadic ones recorded when you unplugged various things. For that you have to do an initial OBD fault reading without starting the engine, and write down all fault codes. Then erase all codes, start the engine, let it run some 10 minutes, or even better till it stalls, then immediately read codes again. Let us know what your findings were. Do not unplug any socket!

I cant seem to find the OBD plug? I thougth it would be left to the steering wheel?

OBD socket was always under the glove box, far right, for Felicia.

Seems there was no OBD on my favorit. But toady it failed again and we tested the sparkplugs again and this time they didnt fire at all? I will try to start the car again tomorrow morning and see if the problem is permanent now.