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Rb20det Afr Issues

nicksamaniac

By nicksamaniac,
in Engines & Forced Induction

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nicksamaniac Collaborator

nicksamaniac

Posted
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Hopefully going in next week for a few hrs with dvs-jez, hopefully he can work it put.

Im at a complete loss on what to do?

Ive been right over it, methodically tested and inspected everything from scratch.

No results thus far, still running like a 2bob watch.

Spoke to a few tuners, decided a fresh set of eyes is next on the to do list.

If I cant get this engine to run as it should, then im not going to waste any more time or money on it, seeing its nothing special anyways, (especially after driving my rb26 or 30det, the 20 is very average) ill drop either an rb25det in or neo 25det in it, then develop from there.

nicksamaniac Collaborator

nicksamaniac

Posted
  • Author
Posted

So I think I may have fixed it?

Between both sets of injectors, my old set from my 25de and the set out of it, ive found 3 dead injectors in total.

So I measured them all for impedance, basket cleanliness, and set them up and ran them with the old cas spin method to trick the ecu into cycling them, 2 would do nothing and 1 would only work 50% of the time, and 2 of the 3 had high resistance,

So I picked 6 that tested up and functioned ok.

Put them in and it started and idled perfect straight away.

Set the base idle and then base timing to 20',

Took for a drive and feels like stock standard again, happy days!

Afrs are not as tidy as id expect for a factory tune, but good enough to drive properly.

They're atleast steady, close to what id target and not crazy rich/lean like it was.

  • Like 1
r33 dylan Apprentice

r33 dylan

Posted
Posted

So I think I may have fixed it?

Between both sets of injectors, my old set from my 25de and the set out of it, ive found 3 dead injectors in total.

So I measured them all for impedance, basket cleanliness, and set them up and ran them with the old cas spin method to trick the ecu into cycling them, 2 would do nothing and 1 would only work 50% of the time, and 2 of the 3 had high resistance,

So I picked 6 that tested up and functioned ok.

Put them in and it started and idled perfect straight away.

Set the base idle and then base timing to 20',

Took for a drive and feels like stock standard again, happy days!

Afrs are not as tidy as id expect for a factory tune, but good enough to drive properly.

They're atleast steady, close to what id target and not crazy rich/lean like it was.

Good to see you got it sorted man! Time for a nistune and a mild tune to get the rest of it running perfect ?
  • 2 weeks later...
nicksamaniac Collaborator

nicksamaniac

Posted
  • Author
Posted

Running issues are intermittently happening still.

So.....

Changed out my fuel rail, reg and injectors from my rb30det (hardware i know works) along with the power fc, loaded an rb20det tune along with all the injector corrections to suit.

Drove around all good, drove it work for night shift (27km trip) and it was perfect, afrs where imo spot on the money, drove really nice, crispy performance.

Then drove home at around 2am, nice cool air about 22' and got about 2 min up the road, solid off scale rich, coughing and sputtering its so rich, all the way home.

So i think, only hardware left is the harness, the rest i know works perfectly in my other car, so i strip the harness looking for a short in the injector signal wires

(thinking they're being held open via a ground short circuit, rub through wire)

And i found nothing but a surprisingly good cond harness.

Fml!

Separately wrapped up the inj signal wires, tapped the harness back up, no change obviously!

So put all the stock hardware back in.

Still rich af at idle, (it stalls/fouls plugs if left idling to long)

Ran a new afm harness back to the ecu today, along with different afm.

Ill test drive tomorrow.

Thing has me stumped......

nicksamaniac Collaborator

nicksamaniac

Posted
  • Author
Posted

Also to mention, i monitored the map watch and afm voltage at cruise speed,

On flat road, afm voltage and load points where solid and holding steady but afrs where rich off scale 10:1 to 13:1 back and forth while holding steady a load point.

This led me to the short in the harness theory, but to no avail.

r33 dylan Apprentice

r33 dylan

Posted
Posted

Running issues are intermittently happening still.

So.....

Changed out my fuel rail, reg and injectors from my rb30det (hardware i know works) along with the power fc, loaded an rb20det tune along with all the injector corrections to suit.

Drove around all good, drove it work for night shift (27km trip) and it was perfect, afrs where imo spot on the money, drove really nice, crispy performance.

Then drove home at around 2am, nice cool air about 22' and got about 2 min up the road, solid off scale rich, coughing and sputtering its so rich, all the way home.

So i think, only hardware left is the harness, the rest i know works perfectly in my other car, so i strip the harness looking for a short in the injector signal wires

(thinking they're being held open via a ground short circuit, rub through wire)

And i found nothing but a surprisingly good cond harness.

Fml!

Separately wrapped up the inj signal wires, tapped the harness back up, no change obviously!

So put all the stock hardware back in.

Still rich af at idle, (it stalls/fouls plugs if left idling to long)

Ran a new afm harness back to the ecu today, along with different afm.

Ill test drive tomorrow.

Thing has me stumped......

As much as I love the rb20dets maybe it's time to just pull the old girl out and source another one or even upgrade to a 25 while your at it? Gotta remember these motors are getting old now a days and could just be old age that's gotten to the inside maybe ?
r33 dylan Apprentice

r33 dylan

Posted
Posted

Running issues are intermittently happening still.

So.....

Changed out my fuel rail, reg and injectors from my rb30det (hardware i know works) along with the power fc, loaded an rb20det tune along with all the injector corrections to suit.

Drove around all good, drove it work for night shift (27km trip) and it was perfect, afrs where imo spot on the money, drove really nice, crispy performance.

Then drove home at around 2am, nice cool air about 22' and got about 2 min up the road, solid off scale rich, coughing and sputtering its so rich, all the way home.

So i think, only hardware left is the harness, the rest i know works perfectly in my other car, so i strip the harness looking for a short in the injector signal wires

(thinking they're being held open via a ground short circuit, rub through wire)

And i found nothing but a surprisingly good cond harness.

Fml!

Separately wrapped up the inj signal wires, tapped the harness back up, no change obviously!

So put all the stock hardware back in.

Still rich af at idle, (it stalls/fouls plugs if left idling to long)

Ran a new afm harness back to the ecu today, along with different afm.

Ill test drive tomorrow.

Thing has me stumped......

As much as I love the rb20dets maybe it's time to just pull the old girl out and source another one or even upgrade to a 25 while your at it? Gotta remember these motors are getting old now a days and could just be old age that's gotten to the inside maybe ?
nicksamaniac Collaborator

nicksamaniac

Posted
  • Author
Posted

Im already getting quotes from a few places, trying to get a halfcut to upgrade the box as well.

Possibly a neo with r33 gb combo i think would work well.

ive completely lost faith in this engine, have even spoke to a few rb tuners, they agree to just upgrade it.

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