RB20DET Misfire

[TakeoSkyline]

Hello, I am new to this forum seeking for help. I own a R32 GTS-T 64k miles and my car keeps getting misfires whenever I drive for 10-15 minutes in a hot day well any day to be honest. I changed the coil pack loom, ignition coils, sparkplugs and still misfires.. but car does feel a lot better with the new parts I just listed. Car runs, and starts good on cold. Could it be my igniter? Fuel Injectors? Timing? O2 sensor? ECU? could be one of those things or possibly more 0_0 I really need some help because I really love my car. 4 months ago I got it compression tested all around 150 and one of them was 140 can't remember which cylinder it was. I changed fuel pump 4 months ago as well because old one decided to go sleep on me. Anywho...please help :(! Any answers would be appreciated! 

 

[robbo_rb180]

1. Get a consult cable and scan for codes.
2. Leak down test to check if valves & rings are sealing.
 3. If no error codes, get wideband and check AFR/Lambda

That 5th plug looks to have oil on it so either rings or valve stem seal could be the issue

These cars are 30 years old and probably have not had all scheduled maintenance done and been flogged over their many owners.
From failing optical sensors in CAS to blocked fuel filters. So many issues with them these days hard to diagnose with out seeing car in person.
 

[GTSBoy]

On 9/1/2022 at 2:24 PM, TakeoSkyline said:

Could it be my igniter?

Absolutely.

There's also almost zero chance that that car has only done 64000 miles. 164000 more likely, 264000 quite probable. That is unless you have owned it since circa the year 2000. 30 years of heat soaking will definitely leave that ignitor not working the way it should. Hell.....they started dying 20 years ago on everyone else's cars.

[TakeoSkyline]

On 9/1/2022 at 12:11 AM, GTSBoy said:

Absolutely.

There's also almost zero chance that that car has only done 64000 miles. 164000 more likely, 264000 quite probable. That is unless you have owned it since circa the year 2000. 30 years of heat soaking will definitely leave that ignitor not working the way it should. Hell.....they started dying 20 years ago on everyone else's cars.

I meant to say 104,000 kilometers haha sorry but yeah thank you for the reply I will be ordering my igniter but did order a few things to replace because might as well right? hehe

[TakeoSkyline]

On 9/1/2022 at 12:01 AM, robbo_rb180 said:

1. Get a consult cable and scan for codes.
2. Leak down test to check if valves & rings are sealing.
 3. If no error codes, get wideband and check AFR/Lambda

That 5th plug looks to have oil on it so either rings or valve stem seal could be the issue

These cars are 30 years old and probably have not had all scheduled maintenance done and been flogged over their many owners.
From failing optical sensors in CAS to blocked fuel filters. So many issues with them these days hard to diagnose with out seeing car in person.
 

Thank you for the reply! I will be doing the 3 things you listed as soon as possible if my igniter and fuel injectors won't do!

[TakeoSkyline]

I forgot to mention my car has a valve cover leak so rubber gaskets might have been old and sucky now but it doesn't look too bad so not enough to leak in the ground but I did get my replacements already and will be doing them soon 😀

[GTSBoy]

On 9/1/2022 at 3:58 PM, TakeoSkyline said:

104,000 kilometer

Being essentially the same as 64000 miles does not change my opinion of the mileage on that car. They were all wound back in Japan, then usually wound back again before sale in their destination country.

On 9/1/2022 at 3:58 PM, TakeoSkyline said:

I will be ordering my igniter but did order a few things to replace because might as well right?

Better off abandoning that old fashioned crap. Buy an R35 (or similar) pencil coil conversion kit. Rewire with a loom kit to get rid of the igniter. Nistune the ECU so you can tweak the dwell and boost off into the sunset.

[TakeoSkyline]

On 9/1/2022 at 1:03 AM, GTSBoy said:

Better off abandoning that old fashioned crap. Buy an R35 (or similar) pencil coil conversion kit. Rewire with a loom kit to get rid of the igniter. Nistune the ECU so you can tweak the dwell and boost off into the sunset.

Yeah for sure, I've watched someone do it on YouTube gonna be doing that this year. The igniter will just be for temporary so won't be using it for anytime soon when I get the r35 coil conversion kit on 😁 Thank you for the suggestion!

[niZmO_Man]

Did you try the solder fix for your AFM?

[ACTIVE-LSD]

Is the ECU stock? Alot of skylines came with Japanese chipped ECUs like mines, impul etc which runs on 100 RON. You could be pinging under load and not even realise.