R3 cold start up misfire.

boosted · January 24, 2015, 09:33:25 AM

Got an intermittent 3-5 sec misfire on the wifes R3 that is perplexing me a lot!

get flashy cel on start up and rough running for 3-5 secs . code reading brings up p0302 rear housing misfire.

car has 38K and been doing this intermittently since just b4 xmas.

car has bhr coils leads and hotter sparks. ( and mini remap to suit coil dwell).

car was due a service soon so brought it forward.

Fitted a brand new battery.

clean the Maf.

New airfilter.

Fresh oil n filter.

Ive swapped rear and front housing coils no change

Ive change the plugs at service time.b4 xmas.

and just fitted new magnecor leads cataclean on last 1/4 of a tank and filled tank and stopped using 50ml of premix.

Car has been perfect for a week but did it again when wife started up to come home.

Ive pulled sparks and there is a fouling on the plugs.....thing is the week the cars been fine i took it out after fitting leads and gave it a hooning for 15 mins ......the wifes using 8 til 6 in rush hour traffic.....ive told her to beep it but due to congestion someime this is impossible.

coolant level is NOT dropping monitored for a month now.

next step is emissions test and compression test?

or remove coils? and put standard on?

car drives great starts instantly hot and pulls all the way to redline.

want todo the nvram reset but not sure if that will wipe the mini remap for the dwell.

ive searched extensively and seem tobe the only 1 with this issue.

Any help greatly appreciated.

boosted · January 24, 2015, 10:18:25 AM

Been out to car and started and perfect. I read a couple of threads on rx8 club regarding dwell on BHR coils. better performance but poorer starting?

tempted to fit new mazda coils and wipe map and ill have the BHR's for the Westy as running a S1 PCM and no known issues.

not sure how many r3's fitted bhr coils? whole new PCM etc.

or barking up the wrong tree? its only the rear housing showing code.

raaaaa!!!!!!!

boosted · February 04, 2015, 07:11:32 PM

Well spoke with Clive at MRP and Aston at Essex Rotary and hatched some corrective measures which involved redoing the earth on the bhr harness and engine earths and eccentric shaft profile clean and reset.
Stuck some more cataclean through it and good a for full week and thought woo hoo...then came back started up instantly 2k rpm soon as revs dropped flashing cel for 4 secs then good allday. BUT Noticed a noise today when i was driving....cat broke up me thinks sounds like metal sloshing about in rear of exhaust and tinkle tinkle noise....sympton or cause of misfire? No power loss at high rpm or funny smells or codes for cat efficiency. Car drives great....wierd and perplexing! only happens on cold start....ill take the cat pipe out this weekend and gut the rest. Mot aint for a while and not gonna risk a new 1 ...

boosted · February 05, 2015, 06:35:01 PM

cat is completely destroyed

boosted · February 28, 2015, 10:22:42 AM

little update. still doing it ! seamfoamed it as well. has the cat from mine on it now as mine sailed through mot...Cat had a melted ball in middle of it....once a week misfire on cold start up....i must be the only 1 with this issue ever. comp test and if that ok then bhr coils off and map changed for std coils. esps changed from race car..... taking up way too much of my time....

re japi · February 28, 2015, 05:34:10 PM

Just read this thread... Very weird... Hopyfully you can get it fixed...

boosted · February 28, 2015, 06:33:03 PM

I'm convinced its the coils or dwell settings now as everything else has been triple checked. swapped around. swapped with spares etc....Ill get Carl to compression test it then a trip to see Aston at Essex Rotary as he has mazda edit and been uber helpful and make a decision on swapping back to oem coils and ill have the bhr's for the westy. only coldstart left allday or first thing in morning and once a week approx somedays starts perfect ...flashes long enough for the CEL to go solid and you can here the misfire fluff fluff fluff. PO302 ! everytime rear housing misfire.
new battery
done coil swap front to rear.
lead swap front to rear
new leads.
new sparks
sparks swapped around.
harness leads swapped
ESP reset.
earths cleaned
maf cleaned.
esp clean
esp swap with race car
seafoamed.
ran with premix
ran without
decat
my cat from mine
constant monitor of coolant level bang on.

after misfire car will run awesome allday. very perplexing

no other codes. if dwell check on BHR and or oem coils dont solve it poss looking at PCM coil driver issue or harness connector or summit!

boosted · April 11, 2015, 10:06:49 AM

Well, think this issue is put to bed.....correlation of months of fact finding and swapping bits.....whenever ive pulled the sparks they been oiled up black not tan colour. i take it for a hooning and it does not start up misfire for a week. Told the wife to rag it 3 beeps a day keeps the misfire away. seems to be working atmo..... $:-\$