Missfire on GTiR

mario_200sx · Post by **mario_200sx** » Tue Mar 01, 2011 4:20 pm

Hey guys, I'm still sitting with a missfire on the GTiR!

Its got a SR20 motor with a distributor. I was told to run BCR8ES plugs but I can't find any! Running BCPR6ES at the moment as this is what we bought the car with.

Any ideas for resolving the missfire? Running stock boost! With forged pistons

mario_200sx · Post by **mario_200sx** » Tue Mar 01, 2011 4:22 pm

Oh yes, it only happens when car is at operating temperature and as soon as you get to 3000RPM

rat · Post by **rat** » Tue Mar 01, 2011 4:26 pm

why such cold plugs?

Boost below 1 bar bcpr6es over 1 bar bcpr7es

djtreble · Post by **djtreble** » Tue Mar 01, 2011 4:30 pm

Have you cleaned the AFM with some carb cleaner and checked all pipes for leaks?

mario_200sx · Post by **mario_200sx** » Tue Mar 01, 2011 4:31 pm

That's what I am running now.

So what else can I look at?

mario_200sx · Post by **mario_200sx** » Tue Mar 01, 2011 4:33 pm

djtreble wrote:Have you cleaned the AFM with some carb cleaner and checked all pipes for leaks?

Yip checked and done

djtreble · Post by **djtreble** » Tue Mar 01, 2011 4:40 pm

Checked timing with timing gun?
Checked the coilpacks? Checked the plugs for the coilpacks?

mario_200sx · Post by **mario_200sx** » Tue Mar 01, 2011 4:45 pm

If it was the coils wouldn't it have done it from start up?

djtreble · Post by **djtreble** » Tue Mar 01, 2011 4:46 pm

No they can be affected by heat, see if you can't find someone with known working ones and test them...not sure if the 200's SR coilpacks fit?

mario_200sx · Post by **mario_200sx** » Tue Mar 01, 2011 5:13 pm

These motors don't have coilpacks, so only the NA sentra, don't know if that's the same however!

djtreble · Post by **djtreble** » Tue Mar 01, 2011 5:15 pm

Ah ok, yeah they would use the dizzy (hence the reason for the difficulties fitting these to the S-body)

All I can suggest is testing these with know working replacements.

BigKriss · Post by **BigKriss** » Thu Mar 03, 2011 7:32 pm

Are your plug wires resister type wires ? Ie: are they suppressed or are they copper core or "wire" wires ?

If wires, do they have additional suppressors fitted at the plug end ?

A "R" in the plug nomenclature indicates a resistor plug . Having all this impedance in the system can kill spark in an engine.

Total impedance should not be more than 4 K Ohm in total.
If your wires are suppressed, try NGK B6/7es plugs, these are non resistive AND do not protrude . "P" stands for a protruding electrode.

As an old school Lancia Intergrale and Alfa Turbo guy I played quite a lot.

My 2c worth..

smoothedgp · Post by **smoothedgp** » Thu Mar 03, 2011 10:57 pm

[quote="BigKriss"]Are your plug wires resister type wires ? Ie: are they suppressed or are they copper core or "wire" wires ?