Rb25 Wont Idle

[grothie]

My r32 with rb25 conversion won't idle after doing a highmount conversion. It will rev fine and pull great. Light throttle coasting it will miss and carry on and it won't idle at all, just dies. I tried different afm. Cleaned aac. Checked all cooler pipes. Checked vac lines that I can see. Took Bov off and blocked vac lines. it idled before I did highmount swap

[Ben C34]

Ok. I am going to assume you changed the turbo, as swapping manifolds tends to suggest that. And as you didn't mention tune, I will assume that no tune was involved. My diagnosis, based on little info and taking a wild guess.... you killed the engine. (broken rings/ ringlands/ head gasket from pinging)

Unless you have more info to add we can only guess.

Edited November 21, 2013 by superben

[Frosty]

more info required. did you add injectors? Standard ECU? Tune? Z32?

or

did you just throw it on and go it will work?

[SkudR33]

Ok. I am going to assume you changed the turbo, as swapping manifolds tends to suggest that. And as you didn't mention tune, I will assume that no tune was involved. My diagnosis, based on little info and taking a wild guess.... you killed the engine. (broken rings/ ringlands/ head gasket from pinging)

Unless you have more info to add we can only guess.

I've broken one of my rings and I occasionally get some blue smoke coming out the tail pipe... My car occasionally has this issue where if I clutch in at high revs, the revs will fall till it hits 0 and stalls... Do you think the 2 issues are related?

[StevenCJR31]

^^ I wouldnt worry about any other issues until you rebuild/replace engine

[SkudR33]

^^ I wouldnt worry about any other issues until you rebuild/replace engine

Yeh can't wait to be honest - picking up rb30 block this weekend to get the project started

[grothie]

Cars only running 5psi have barely driven it since I did highmount

[ido09s]

That doesnt mean much

Has the turbo been upgraded and was it just thrown on and hope for the best?

is it a stock engine and how many kilometres. It still could have cracked a ring land but hopefully for your sake its probably just not tuned properly

Edited November 22, 2013 by ido09s

[grothie]

Stock engine. Compression is 160 across the board. Upgraded turbo around 140k

[grothie]

Was only replacing to get a tune and now would like to rectify all problems before I go ahead wasting tuners time

[grothie]

Was just idling for about 30 seconds perfectly then starred to die off running low

[ido09s]

soiunds to me like it just needs a tune, though i dont know how it would affect the idle tune that badly

[abr33]

Turbo will have next to zero affect on idle..

[Ben C34]

Check everything you touched, as you must have done something cos you said it was fine before. No one is going to be able to pinpoint your problem for you over the net.

[Ben C34]

Was only replacing to get a tune and now would like to rectify all problems before I go ahead wasting tuners time

This makes no sense.

[Frosty]

Turbo will have next to zero affect on idle..

this isnt entirely true because the AFM will read more air flow on adjust fuel mixture on idle etc etc etc

[abr33]

this isnt entirely true because the AFM will read more air flow on adjust fuel mixture on idle etc etc etc

Ah I forgot about afm. Been running a map to long to remember haha. Still shouldnt be a problem at steady idle though?

[ido09s]

I highly doubt the engine would draw more air at idle just because it has a larger turbo on it..... but stranger things have happened and the inlet could have had some affect on the air flow through the AFM if its running one which has caused it

Edited November 22, 2013 by ido09s

[Frosty]

it can happen as all air is drawn through the AFM even on idle and thus bigger turbo takes more air (idle or not)

im not say this is the issue however food for though as we still do know any further information to help diagnose

[Ben C34]

it can happen as all air is drawn through the AFM even on idle and thus bigger turbo takes more air (idle or not)

im not say this is the issue however food for though as we still do know any further information to help diagnose

I have to disagree with that. I can't see how the turbo that's not bring driven enough by the exhaust would have any effect at idle. If you pulled the afm off a nice running car and took apart turbo system then put afm onto throttle body I bet it would idle fine.