backfiring in intake

[yimpkinwoody]

Hi all, I have a 740 2.0 estate with a voltron LPG conversion. It has sudenly started backfiring in the intake and is getting worse. Its had new plugs, leads, distributor cap and rotor arm. it runs fine on petrol, but as soon as you switch on the gas its like a machine gun going off. It has split the air cleaner box open and blown the filter out. I cannot find any information on the Voltron system. Anyone got any ideas? Were can I get a wiring diagram for this system?

[classicswede]

No need for wiring diagram.

The plugs leads etc are likely to be the cause of the intial problems but now because the pipes are split it will be running lean.
Try taping the pipe up and see if that works. If not then mark the position on the in line gas adjuster and open it out about half a turn to richen it up.

Take some photos to show how the system is installed and post them up.

[yimpkinwoody]

Hi, I checked all the intake pipes and tried richening the gas. Its still backfiring and split the hose betwen the air mass sensor and the intake manifold. I got a good second hand one from a pal who banger races Volvos and tried again. this time I did not tighten the hose clip at the mass meter. It backfired and blew the pipe off. There is a flap valve on the airbox casing, but it seems to overwelm it. I do not have a didgital camera so cannot post pic's. the gass comes from a circular coolant heated unit to a pair of jets in an aluminium spacer on the inlet manifold. The reason I wanted a wiring diagram is that the car is coming to the end of its life and I was planing to take the conversion off for my next volvo. Anyway, I will try blanking off the various brether pipes and clean out the gas pipes and jets and have another go. My oldest son is home for easter, so will get him to take pic's and post them. Regards Woody

[classicswede]

Pics will help. Is it only backfire under load or pretty much all the time?

[yimpkinwoody]

Thanks for your reply. Its backfiring all the time. load seems to make no difference. Is it possible to convert to the LPG feeding the injectors? or would that involve a new kit. I have serched the web, but can find no information on Voltron. anyone know if they are still trading. regards to all Woody

[classicswede]

Backfiring all the time syggest you have ignition problems. Have a good look over everything again. Start the engine in teh dark and look for sparks from teh HT leads. It could possibly be a bad air leak so check all the pipes are on teh manifold and that both pipes are still on the idle control valve. The ICV pipes often blow off with a backfire and need to be left loose.

It is not possible to convert to LPG injection on K jectronic and all front end componets are totaly different. Voltran is sold by WTV