CNG Performance: Spark Plugs

[Genie47]

Here is my review on CNG performance and how spark plug can really make a difference.

 

When I first got it installed, I was using the 100k mileage double platinum plugs. The car jerked and choked like an old geezer.

 

OK, so I changed it to NGK BKR6E-11 gapped to 0.95mm. Performance on gas was as before but petrol is fine. Then my ignition coils and flywheel pickup sensor died. Got them replaced and still, the gas performance is bad.

 

Finally the car hit 120k. Had the timing belt changed and plugs changed. This time they are Volker 465 regular plugs gapped to 0.95mm. It choked on gas and petrol. These must be really bad plugs. After 3 days I had enough. Something has to be done.

 

OK, I asked Falc for the NGK BKR7E plugs he has. He tells me he was not using them because he is already on NGK IridiumIX.

 

With a heavy heart I called Terence, except that Terence is not in town so his biz partner answered. Went down braving PIE jam from BKE to Eunos in the evening rush hour to reach there at 8pm to get the BKR7EIX plugs.

 

Got them back and gapping them is a chore. I had to be ginger with them. The plugs were pre-gapped to 0.3mm. Finally got them to 0.95mm.

 

Installed them late at 12am in the morning and then drove around the MSCP. Fine.

 

Next day drove to and fro from work but I didn't have any gas to try it. They were better than the Volkers by a wide margin.

 

Then Sat came and I went to JB to fill up on gas. Returned and ran it on gas.

 

Wonderful! No jerks. No chokes. No hesitation! Even on uphill when the BKR6E-11 plugs choked and flooring it slightly made it worse.

 

Fine wire plugs did the job. I was skeptical and wanted the cheap way out using regular BKR6E-11. So now the BKR7EIX works. Second test which will be a follow up on this post will be how long this honeymoon is going to last i.e. how long these plugs will keep their gap. My car runs on a wasted spark system. There is a reverse spark on a non-compressoin stroke so the wear rate is twice. I'll see by then.

 

On top of all those above. I would be glad to say the torture test for an ignition system is CNG as fuel since it is very difficult to ionize the mixture to produce a spark.

Edited November 3, 2007 by Genie47

[Cyberet]

guess its real difficult igniting that 120ron gas

[Tianmo]

Here is my review on CNG performance and how spark plug can really make a difference.

 

When I first got it installed, I was using the 100k mileage double platinum plugs. The car jerked and choked like an old geezer.

 

OK, so I changed it to NGK BKR6E-11 gapped to 0.95mm. Performance on gas was as before but petrol is fine. Then my ignition coils and flywheel pickup sensor died. Got them replaced and still, the gas performance is bad.

 

Finally the car hit 120k. Had the timing belt changed and plugs changed. This time they are Volker 465 regular plugs gapped to 0.95mm. It choked on gas and petrol. These must be really bad plugs. After 3 days I had enough. Something has to be done.

 

OK, I asked Falc for the NGK BKR7E plugs he has. He tells me he was not using them because he is already on NGK IridiumIX.

 

With a heavy heart I called Terence, except that Terence is not in town so his biz partner answered. Went down braving PIE jam from BKE to Eunos in the evening rush hour to reach there at 8pm to get the BKR7EIX plugs.

 

Got them back and gapping them is a chore. I had to be ginger with them. The plugs were pre-gapped to 0.3mm. Finally got them to 0.95mm.

 

Installed them late at 12am in the morning and then drove around the MSCP. Fine.

 

Next day drove to and fro from work but I didn't have any gas to try it. They were better than the Volkers by a wide margin.

 

Then Sat came and I went to JB to fill up on gas. Returned and ran it on gas.

 

Wonderful! No jerks. No chokes. No hesitation! Even on uphill when the BKR6E-11 plugs choked and flooring it slightly made it worse.

 

Fine wire plugs did the job. I was skeptical and wanted the cheap way out using regular BKR6E-11. So now the BKR7EIX works. Second test which will be a follow up on this post will be how long this honeymoon is going to last i.e. how long these plugs will keep their gap. My car runs on a wasted spark system. There is a reverse spark on a non-compressoin stroke so the wear rate is twice. I'll see by then.

 

On top of all those above. I would be glad to say the torture test for an ignition system is CNG as fuel since it is very difficult to ionize the mixture to produce a spark.

 

 

Bro Genie

 

about this spark plug thingy with our CNG. after I changed the plug cable and plugs everything seems ok now.

 

I am on the NGK BKR6E plugs, think they are 1.1mm gap, I did not re-gap them but just insert them as they were. You mention that we sld gap them to 1mm or 0.9mm, sld I re-gap them or can I leave them as they are now. would it hurt the cables and the coil?

 

also I read it the MY NGV forum about the Bosch super 4 plugs been good for their cars, do you think it is worth to try them?

 

many thanks!

[Genie47]

If it is performing OK, no need.

 

It will stress the wire set and coil. This means they might fail earlier. Decision is yours.

 

For plugs, stick to the BKR6E.

[Tianmo]

Ok. Guess I better stick to BKR6E and gap them down to 0.9-1mm.

 

Thanks Bro!

[Mini-itx]

Wah 0.95mm is a little big for stock coils. Suggest you go for aftermarket coils instead. I am using Mallory Pro Master and on 1.1mm gap. Very good.

Edited July 21, 2010 by Mini-itx

[Genie47]

Wah 0.95mm is a little big for stock coils. Suggest you go for aftermarket coils instead. I am using Mallory Pro Master and on 1.1mm gap. Very good.

 

1.1mm gap is the default for the GMDAT engines. There is also a problem with using MSD or Mallory Pro Master for these engines. For some strange reason the driver and the coil are in the same package. So replace the coil, there is no driver for the ignition system!