Drives like a kangaroo

[pascal21]

Hi Im David from Ireland,
I have recently purchased a 1994 Toyota 4Runner, 3Litre V6, manual with 106,000 miles on her. It is is LPG/Gas converted.

Here is the problem- I put on a K&N air filter, and all was goin well until one day as it was running out of LPG it started to chugg- this was normal(when this happens you just switch to petrol) but this time as i was switching across, it back fired and blew the air filter off along with the air flow meter and the car stalled and would not start again untill I screwed the air filter back on again. but then as I drove it after it started chugging and driving like a kangaroo, especially in 4th and 5th gear. It has been doing this ever since, the engine used to idle at 1,500rpm but now it idles at 500rpm, sometimes it starts fine(idling at 1,500rpm) and drives fine then it starts to go funny again and kangaroo. and when i switch it to LPG it still drives funny and when i clutch it on LPG, the revs drope right down and it stalls. I have since put the original air filter system back on but the problem remains.

Is it possible the engine was damaged when the air filter/meter blew off? Or do yous have any idea? I know that LPG connverted cars is not a common thing, and I certainly dont have clue about them!
Thanks a million, David McFarland

[BUSHWHACKER]

Another member on here, 'Truckarms' had the same problem with blowback on LPG, His AFM was damaged. There's a thread on here somewhere that shows what the problem was, TonyN repaired or soldered something to fix it, but I think he fitted an AFM from a V8 now.

Maybe search on here or e-mail Truckarms.

[Sancho]

Hi David,

When was the last time you drove a kangaroo? I have chased plenty, but never driven one.

Anyway, as Vince says, Truckarms had a similar problem on his V6 where a backfire buggered the AFM. As I recall, there was some kind of internal switch that got blown into a position where the AFM thought there was no air so cut the fuel.

Edit: Here's the thread. God, I'm nice

http://www.hiluxsurf.co.uk/forums/sh...ad.php?t=28552

[truckarms]

Hi,
Yes I had the same problem but with a different result, mine would start and then stop, the starter motor controls the fuel pump to start the engine and then the AFM takes over, when the airflow meter took over the engine would stop as it turned the fuel pump off.
But the AFM does control lots of things so I would agree with the other guys that that is your problem.
Fixing it is tricky, if you have a hanyes manual see what all the wires in the AFM conect to and check nothing is broken. DO NOT unscrew the wires from the back of the AFM, undo the clip and pull the connector off, if you unscrew it you will cut some other wires and cause more problems!!!
If that fails all I can suggest is trying to find a replacement one and they are not easy to find.

Hope that helps, email me if you want anything else and i will email you my number.

Cheers and good luck

[truckarms]

I have not tried this but it might help.

http://www.automotiveforums.com/vbul...51&postcount=8

[pascal21]

Thanks so much everyone

Thanks so much everyone for your help, I will try to have a go at fixing it by opening the AFM, my dads very good at electronics, he will help me. I priced one at a breakers near me, he is the biggest in Ireland, but a real scumbag, he tells me £70 for it, but he probably doesnt even have it, and if you try to barter with him hes be know to give you a cheaper price then smash the thing right in front of you! so i really dont want to give him the business. Thanks again guys.
David

[truckarms]

70 quid is not too bad,
I paid about 40 quid for mine.
New they are 300 quid or so.