Hi Will Ferch, and all spark plugs experts.

rnln · 09:46 AM

Hi Will,

If you remember, we were talking about NGK plugs I got on my car maybe 2 months ago. I was using BP7ES which was a mistaken instead of BP6ES. You were saying this BP7ES will be a little too cold for my carrera 88 engine, just redline it sometimes then I will be fine.

Well, after swaping to this NGK BP7ES plugs, from Bosch Platinum which was running well for years, I feel the car slightly shake at IDLE only. I know people recommend me to check on wires, etc but I don't have the time yet.

Yesterday was the first cold day this year, today I experience some weird performance while I was on the freeway this morning. At 5th gear on highway, once in a while I felt like someone is occational pulls the car back from behind while it "jump" slightly like bad rear shocks (never before), hard to feel the shake. If I shift down to 4th, then it's normal. Then I paied attention at the tach meter, I think I was running at a tiny bit higher RPM.

When I got to the local street, once (only once) I was shifting from 1st to 2nd, the car didn't want to go for around 2 seconds. During that seconds duration, I felt very slow and heavy.

Do you think the cause of these symptoms are because I am using too cold plugs, BP7ES, and the weather is getting cold now?
Thank you.

IROC · IROC's Garage

I'm not sure what your problem is, but I would not think that it is the plugs. I am using NGK BPR8ES plugs in my '88 3.2, although I have 10.3:1 compression. The plugs work fine. I've used both BPR6ES and the BPR8ES and there is no noticeable difference in drivability.

I'd throw a bottle of Techron in the engine.

rnln · 09-19-2007, 09:46 AM

You meant the additive, or the octan booster?

rnln · 09-21-2007, 05:10 PM

After another drive, I found that it only happen at around 3k rpm and cruising at 5th gear. Reving from 1st to 4th gear are all good. But when the car is cruising around 3k rpm and up, most likely it will happen. The worst it get is when traffic comes, enough to keep going at 3k. It would shake and doesn't want to get up when I kick on the gas pedal.
I will replace some ignition parts and let see.