Quote Originally Posted by Louga View Post
hello po, anyone experience cold start rpm issue when using lpg?

issue: during cold start yun rpm ko will shoot to 1500 (normal) but suddenly will drop to 900 then after about 10-15secs will gradually goes up to 1300-1500 (normal warm up rpm for cold start) then will gradually goes down na (kasi umiinit na un engine). yun issue is the sudden drop to 900 kahit malamig pa engine kaya parang tunog palyado yun makina. i believe the proper warm up rpm on cold startup is shoot to 1300-1500 then gradually goes down to normal idle.

scenario:
1. use lpg for several days (warm up lng un gasoline) - cold start rpm issue happens.
2. use gasoline exclusively for a day or 2 - cold start rpm goes back to normal even if you use lpg for couple of days (after the exclusive gasoline run)
3. went to baguio and use lpg all thru out except on the "city driving" on baguio - issue never happens pag start ko the following day.

i haven't experience/feel any unusual sa takbo ng makina both on gas and lpg. engine runs smooth. kahit patakbuhin ko siya na andon pa sa state ng mababa un rpm niya (900 but engine is still cold) ok man siya. hindi siya un namamatay or parang mamatay.

my unit is innova 2009 sgi from greenfuel converted feb 2010 and currently runs 2200km on lpg. current odo is 22+k. yun fuel filter ko hindi pa napapalitan (i know 40k ata bago palitan ito). pinalinisan ko lang sa shell station. air filter, spark plug kakapalit pa lng non 20k pms. pinasilip ko sa kasa sabi ok man daw ecu ko. wala man daw fault na nakita.

ano kaya issue nito? may long term effect ba ito sa engine ko or hayaan ko na lng since pag gas mode hindi siya nag occur?

sorry masyado mahaba paliwanag. TIA

I have a similar problem before. It was traced to a couple of defective sensors on the engine. One was the temp sensor used by the engine to detect if the engine was reached normal operating temp. The sensor would tell the ECU that the engine was warm already even if the engine was still actually cold resulting in a rough idle on cold starts.

The sensor was functional enough not to throw a "fault" but defective enough to give the wrong info.