RS13 91' CA18det starting problem

[BaabaRS13]

CA18det with LPG
ECU code 55, wont start, dont know why but it starts when I put hand on AFM and 90% close it. In some way engine recieves too much air. When it start and swich on LPG I can move my hand and it runs and drives like a dream.

Changed the fuel filter - no change
Diconnect AFM - no start

TPS aligment, dirty injectors or something else ...?

Please help

[PapaSmurf2k3]

With LPG I'm a little out of my element, but do you have any tuning changes that went along with the conversion? Like an ECU?

You can think, either its getting too much air, or not enough fuel (or vice versa). I'm guessing it starts fine if you use some starting fluid or something? Can you smell fuel when cranking?

[BaabaRS13]

[youtube] https://www.youtube.com/watch?v=nERrHuf ... ata_player [/youtube]

[BaabaRS13]

If someone met similar problem?

[PapaSmurf2k3]

To me that screams that your tune is bad.

Once the MAF starts metering air (and adjusting the fuel accordingly), it dies. It also seems like you probably have a vacuum leak somewhere... which is probably helping you haha.
I bet you're running too rich. I'm not sure how your LPG is injected into the engine, but you could try downsizing the injectors/jets, and/or lowering the pressure.

[BaabaRS13]

It was bad fuel pump. I suposed it can't build enough pressure anymore and that was.
Now walbro pump from SAAB Aero turbo is on. Maybe just to clean injectors now and it is all good.

[PapaSmurf2k3]

Awesome! I was thinking you were blocking the MAF and it was sucking air in somewhere else, making your mixture correct, but I guess you were just blocking it to the point where it was barely sucking in any air at all so your fuel pump could keep up.