stalling at idle, error code 13

[defecat0r]

hey guys,

I've got issues at the moment with my Series 2 manual V6 on lpg. The car is running fine on lpg, but is stalling and running really bad on petrol.

If i turn the car on, on petrol, it runs fine for a few seconds, then the revs drop and it stalls in 5 - 10 seconds. The engine light comes on after about a second of turning the car on.

If i'm on the highway and i flick it to petrol, the engine light comes on straight away and it seems almost ok'ish until i put my foot on the pedal where i get a BIG dead spot, then finally some acceleration when i've got the pedal down a fair way. It doesn't seem to be missing at all when it's idling or i've not got my foot on the throttle.

I've put a paper clip on the ALDL cable, and got the flashing engine code 13 which is Oxy sensor. The oxy sensor seems plausible as gas apparently doesn't use the oxy sensor which would explain why it runs fine on lpg.
I've had a 2-wire oxy sensor which i replaced today with a single wire one (and put the negative coming from the computer to ground). But..... it didn't fix the problem. i tried running it with the oxy sensor unplugged, with the original before i changed it and now with the new one, and get the same result every time - the engine light coming on and a stall in about 5-10 seconds.

Some work people thought it might be the fact that i haven't put petrol in it for a couple of months and it might have gone bad, but i put some premium and injector cleaner in and it hasn't made a difference. Also, i do run it a very little bit every couple of days and haven't noticed any problems with performance.

The only other things i thought it could be would be the fuel pump or the injectors. The fuel pump SOUNDS fine when turning the ignition on and off though, and i can hear it whirring away when it's running, then slowing down and stopping after it's stalled, so i'm pretty sure it's not that. And seeing as the car is starting fine for that first couple of seconds and never seems to be missing even when i rev it, i don't think it could be the injectors.

Anyway, i'm fairly n00b at all this, has anyone got any ideas?
could the wiring be damaged somewhere from the sensor to the computer? I don't know where it plugs into the computer. Could the computer be stuffed like this? What does the car usually do when the oxy sensor is unplugged?

thanks for any ideas fellas

[defecat0r]

oh no, i'm an idiot. Read "Checking your Computer for Faults" thread again and i see it can show more than one code, i wasn't waiting for a second set of flashes! So it's also flashing 34 which is map sensor.
And i've gone and left my max elleries manual at work and won't be there next week :'(

So yea, IDIOT, does a bodgey map sensor sound like it would give these symptoms? Can you clean it or do you buy a new one? can anyone give me an indication where to look for it even?

[Cogez]

My car had a broken hose on the MAP sensor when the inlet manifold was taken off. It made a HUGE difference to performance, the car barely moved, it took me ten minutes of stalling and starting to get it 500m back to the mechanic :P

The MAP sensor was replaced, and the problem was fixed

Code 13 refers to an open circuit in the oxy sensor circuit, so an important wire has fallen off somewhere, or the oxygen sensor has been spoiled or broken. Rip it out, and check all the wiring, see if it gets rid of the engine light. Don't forget to reset the codes when you change **** :P

[defecat0r]

oh right, well from the sounds of it i've got the same problem then getting my manual tomorrow, so i'll find the thing and look for any damage then.

Do ya have to reset the computer's fault codes? haven't read about that. Maybe if i could do that my oxy sensor code would go away now that i've replaced it... hope so, coz tracing the wiring back to the computer wouldn't be fun.

Anyway, cheers for the reply dude, looks like i'm on the right track

[defecat0r]

ok! so i've got the problem fixed now. Got my manual and now know that that box thing sitting between the air con and the throttle body is the map sensor! The plug had come loose and tightening that up has fixed my problem.
Also had a browse around the forum and see that to reset the ECU you just take the 'engine' fuse out of the fuse panel in the engine bay for a minute. "System OK" code 12 now

I guess it makes sence that the oxy sensor is causing the ECU to throw a fault. Without the MAP sensor it obviously doesn't know what it's doing fuel wise, which the oxy sensor picks up. Pitty i had to fork out 60 something bucks for a new oxy sensor, but it's a lesson learnt i guess

In case anyone else reading this is as ignorant as me, here's a pic of the MAP sensor