Auto-LPG and sparkplugs...

[ghosthunter]

I have noticed with some of our cars equipped with SGI-AutoLPG.

The cars with SGI Auto-LPG systems have a tendency to "wear out" sparkplugs resulting in uneven idle, power loss or even engine stalling.

The vehicles are:

Honda City 1.3L DSi
Ford Expedition
Mazda 3 1.6L

I am not sure if the tuning (lean) is the fault or simply the use of LPG itself (which is said to have a hotter ignition temperature than gasoline).

As for potential solutions, using platinum tipped sparkplugs seems to be the leading solution in the web.

Has anyone else have similar experiences?

[n5110]

my emulator kit was installed last aug 08. last month i check the condition of my sparkplugs (http://tsikot.yehey.com/forums/showt...29208&page=150) color brown and looks normal naman. im still using the stock plugs. will check again bukas siguro before heading to tagaytay.

will the platinum tipped plugs also improve the FC? magkano ba ito? thanks.

[ghosthunter]

my emulator kit was installed last aug 08. last month i check the condition of my sparkplugs (http://tsikot.yehey.com/forums/showt...29208&page=150) color brown and looks normal naman. im still using the stock plugs. will check again bukas siguro before heading to tagaytay.

emulator/venturi kits seems to be immune to such problems since they are usually tuned to run richer which results in a cooler combusion temperature.

will the platinum tipped plugs also improve the FC? magkano ba ito? thanks.

IMHO, no. They just last longer especially in higher performance engines. Usually cost 1.5 to three times the price of ordinary sparkplugs.

[Mile2]

Just checked my spark plugs yesterday and they are still okay, with only white powdery stains and no burn out signs.

BTW, the spark plugs now runs 10,000++ kms on LPG (Denso Iridium IKH22 one step colder)

My previous stock plugs (Denso K20HR-U11) on LPG seems to have burn out ground tips even less than 5,000 kms.

[vinj]

So far i have no such experiences with the Altis and when i changed plugs, my old plugs were clean and were worn normally. What i did though was to change to platinum tipped plugs with a one-step higher heat range since the LPG burns hotter then regular unleaded; i'm using NGK BKR6E platinums (vs. the normal BKR5E or it's Denso equivalent). They don't cost much more then regular copper plugs as well.

[Mile2]

So far i have no such experiences with the Altis and when i changed plugs, my old plugs were clean and were worn normally. What i did though was to change to platinum tipped plugs with a one-step higher heat range since the LPG burns hotter then regular unleaded; i'm using NGK BKR6E platinums (vs. the normal BKR5E or it's Denso equivalent). They don't cost much more then regular copper plugs as well.

I think BKR6E is one step colder. For Japanese manufacturers (NGK, Denso), the higher the number, the colder the plug.

[n5110]

just check on my plugs today, looks almost the same when i open up last month, a little bit on the dark brown side, dry texture. clean up using wire brush and a little sand paper.

do you guys also clean your plugs? if yes, how do you clean it? how do you know if you need to replace them? thanks.

greenfuel adjusted my settings a little lean, kasi sabi ko i want to improve the FC, now im averaging 8kplpg mixed city and highway nag improve ng konti. pwede ko pa kaya ipa adjust more lean judging from my plugs condition?




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[kikoteng]

Hi Guys !

Sorry to revive an old thread but anyway ... would like to ask for more opinions on this subject matter.

My ride is a corolla lovelife xl with venturi kit lpg. Have tried several plugs with diff. observations.

1. denso w16exu ordinary copper plugs - wears out before 5t km .. loses power especially when driving for 2+ hours .

2. denso w20exu - one step colder than previous - also wears out before 5t km but better response especially during acceleration.

3. bosch super 4 copper - wears out at around 5t km but expensive for a copper plug. Was hoping it would last much longer because of its price. Response was good and idle was smoother.

4. Bosch platinum wr7dp (one step colder) - installed for about 2-3 weeks. Response is good. But when engine is still cold, engine dies intermittently during idle.

5. Bosch platinum wr8dp (regular temp) - installed for 2 days. When engine is cold, engine does not die. But when i drove the car around town for around 2 hours, car hesitates & seems to lose power. Also, heard pops from the engine when accelerating.


Questions :
1. On Spark #5 - are the pops what they call engine knock ? is it because the plugs are not one step colder ?

2. Re spark #4 - anyone experienced this ? Any suggestion on how to solve this ? Make LPG richer ? Increase idle speed ?

3. Noticed that copper plugs wear out quickly compared to using gas. Cant say that yet for platinum. Do you also experience copper plugs wearing out early ?

4. Out of curiosity, does denso make platinum plugs ? Iridium plugs are quite pricey.


Thanks.

[ghosthunter]

I have a 99 Corolla GLi with venturi kit. I have used regular (copper) NGK regular temp sparkplugs with no problems. There are instances where my plugs are still good after 5000km that I just have them cleaned and used for another 5000km.

I am curious why you are going through sparkplugs so fast. Is your Auto-LPG kit adjusted to run leaner than normal?

Popping sounds? Does it sound like shaking a tin-can full of rocks? If yes, you are running your ignition too advanced or fuel too lean.

Try checking/setting your ignition to stock/factory and adjust your LPG flow to slightly richer.

Currently I am running my car on a set of Bosch Platinums (one step colder) just to see if I can get better mileage.

[kikoteng]

I am curious why you are going through sparkplugs so fast. Is your Auto-LPG kit adjusted to run leaner than normal?

Popping sounds? Does it sound like shaking a tin-can full of rocks? If yes, you are running your ignition too advanced or fuel too lean.

About running leaner, I try to lessen the LPG flow to minimize smell of LPG from exhaust especially during startup. I am assuming though that having the smell of LPG means the LPG flow is too rich. Would that be a correct assumption ?

Actually, it only happened with the Bosch regular temp platinum plugs. Never with the other plugs. The sound would be only single pops. It sounds more like a 'triangulo' and it happened twice yesterday while accelerating along SLEX.

Been driving car the whole day yesterday. No problems until I was on my way home. The only thing I can think of is that the car has been in use for 2+ hours.

[ghosthunter]

About running leaner, I try to lessen the LPG flow to minimize smell of LPG from exhaust especially during startup. I am assuming though that having the smell of LPG means the LPG flow is too rich. Would that be a correct assumption ?

roughly correct but your nose is not precise enough to measure how lean or rich your air-fuel mix is.

Actually, it only happened with the Bosch regular temp platinum plugs. Never with the other plugs. The sound would be only single pops. It sounds more like a 'triangulo' and it happened twice yesterday while accelerating along SLEX.

Been driving car the whole day yesterday. No problems until I was on my way home. The only thing I can think of is that the car has been in use for 2+ hours.

Might be your engine is running lean causing a hot spot to happen resulting in pre-ignition. Adjusting for more fuel flow should correct the problem.

[kikoteng]

roughly correct but your nose is not precise enough to measure how lean or rich your air-fuel mix is.




Might be your engine is running lean causing a hot spot to happen resulting in pre-ignition. Adjusting for more fuel flow should correct the problem.

Any idea (DIY method) on how to set the correct air-fuel mix for LPG ?

[ghosthunter]

Any idea (DIY method) on how to set the correct air-fuel mix for LPG ?

why not just look for a Auto-LPG station that offers "free" LPG tuning if you buy fuel from them?

CLEANFUEL (shaw) offers this service.

[kikoteng]

why not just look for a Auto-LPG station that offers "free" LPG tuning if you buy fuel from them?

CLEANFUEL (shaw) offers this service.

Didnt know about that. Thanks for the info.

[vinj]

Right now i'm using the NGK BKR GAS which is designed for LPG and CNG vehicles.

Its running well with FC still consistent when i was using BKR6E-GPs however i noticed the car hard starts when i run it on gasoline for extended periods.

Saw NGK BKR7E's (two step colder than stock) so i'll try these out just as well on my next plug change.

[vernieg]

Nakakita na ako ng Bosch platinum spark plugs on a daily driven taxi na after six months of using lpg sira na ang negative electrode ng spark plug due to acidic type of corrosion. Same thing will happen to upper cylinder block over time, mas mauna nga lang ang spark plug. Such corrosion did not happened to gasoline engines. It is a fuel combustion by product issue and not a fuel-air mixture issue.

Ask an experienced mekaniko or visit their shop, those who have serviced cars running lpg, they will tell you the real story about cars using lpg. Other than health problems experienced by taxi drivers using lpg, this corrosion issue is a big problem for car owners.

Fortunately, nag sulpotan na ngayon ang mga spark plugs for LPG use.

example:
http://www.bosch.com.au/content/language1/html/6578.htm


Unfortunately, the upper cylinder block replacement ay hindi madali mahanap unless daming surplus na pumapasok. Kahit meron mang supply ng upper cylinder block, it is not still practical to have it replaced from time to time.

Did anyone question about the quality of lpg fuel used for cars here in our country? I hope someone will.

I have noticed with some of our cars equipped with SGI-AutoLPG.

The cars with SGI Auto-LPG systems have a tendency to "wear out" sparkplugs resulting in uneven idle, power loss or even engine stalling.

[ghosthunter]

Nakakita na ako ng Bosch platinum spark plugs on a daily driven taxi na after six months of using lpg sira na ang negative electrode ng spark plug due to acidic type of corrosion. Same thing will happen to upper cylinder block over time, mas mauna nga lang ang spark plug. Such corrosion did not happened to gasoline engines. It is a fuel combustion by product issue and not a fuel-air mixture issue.

Ask an experienced mekaniko or visit their shop, those who have serviced cars running lpg, they will tell you the real story about cars using lpg. Other than health problems experienced by taxi drivers using lpg, this corrosion issue is a big problem for car owners.

I am still more convinced that the so-called corrosion is actually pitting caused by detonation due to improper air/fuel mixtures. Richer mixtures should prevent this.

BTW, lean air-fuel mixtures does generate more NOx which results in higher than normal nitric acid during combustion. Given that taxi drivers have a bad habit of adjusting their LPG systems to running leaner than normal, I would not be surprised if taxi units encounter this problem more than privately owned cars.