Rb20 Running Lean

[aahh32]

hey guys and girls just wondering if anybody has any advice on what to try next

the engine is a silvertop rb20det i recently purchased it from adelaide jap dismantlers and put it into a 93 r32 gtst type m i have.

After getting it all in and hooked up i took it to jaustech automotive to get it started cos im not the most experienced when it comes to timing, and they said they did the timing but when they put it on the dyno it was running really lean and he told me the fuel pum needed to be replaced, so i used an r33 gtst fuel pump from a mate it was in perfect condition of a super low km car and i took it back for another run and this is the result (dyno printout below we couldnt rev it over 3000rpm cos it was leaning out) its the same as the first time.

i have had the injectors and fuel pressure checked and they passed, after these dyno's were done i noticed that the car was running really badly (missing at idle and gutless) a mate said the timing was so far out its not funny and he fixed it but he could only do it by ear, when we took it for a drive it ran like it should do no missing at idle and the power i would expect form a near stock rb20det.

i havent had the time to take it back to a dyno yet but just wondering if bad timing could be the cause of it leaning out on boost?

the only mods this r32 has atm are 3" exhaust, dump and front pipe 3" also, pod filter, fmic and i think thats it off the top of my head??

cheers for the help

[SLED]

looking at those AFR's, I'd be putting around like an old lady until you get it sorted.

Couldn't the tuner advise you?

EDIT: You can play around with ignition timing all day but it won't mean squat if your valve timing is out by even 1 tooth.

[aahh32]

looking at those AFR's, I'd be putting around like an old lady until you get it sorted.

Couldn't the tuner advise you?

atm its just sitting in the back yard but i want it on the road asap cos im sick of driving a high powered car i want a close to stock one for daily driving

[aahh32]

looking at those AFR's, I'd be putting around like an old lady until you get it sorted.

Couldn't the tuner advise you?

EDIT: You can play around with ignition timing all day but it won't mean squat if your valve timing is out by even 1 tooth.

how does the valve timing end up out? and how do you check / fix it?

and no the tuner didnt seem to know what he was doing anyway he just kept saying 1 thing aand when i replace or eliminated it he just said something different got a little repetitive after a while. so now i want to find out what the most likely problem is, fix that then take it back to a dyno

Edited January 19, 2010 by aahh32

[rad100]

take it to another workshop... cough boostworx cough

[RubyRS4]

take it to another workshop... cough boostworx cough

+1 for Boostworx, or Willall, or Southern Hi Tech, or Graham West. They all know their Skylines.

[Damo_R34]

atm its just sitting in the back yard but i want it on the road asap cos im sick of driving a high powered car i want a close to stock one for daily driving

high powered with 84 rwkw?

[aahh32]

high powered with 84 rwkw?

lol nah the 84kw is under 3000rpm and that dyno sheet is for the skyline im trying to get running the other one has 301rwkw

[Damo_R34]

haha fair enough

I use and recommend Boostworks, now conveniently located for Norfies at Cavan

[aahh32]

cheers guys ill give those shops a call when i get some free time ^^^ how did you know i was a norfie lol

Edited January 19, 2010 by aahh32

[D_Stirls]

you do have the FPR hooked up to a boost signal? The fuel pressure is checked at idle generally and if the boost signal isn't hooked up you will be losing the extra pressure that you get with boost. If the Fuel pressure is fine throughout the rev range (i.e. base pressure + 1:1 psi with boost pressure) then it has to be either the wrong sized injectors are fitted or the Fuel mapping is out; timing has a slight effect on AFR's but it is only slight not the 4 point difference that you are looking at as nissan factory AFR's can be as low as 10:1 especially when slightly boosted.

What ECU did you use? the one that was in your car originally or one that came with the engine.

And when you put the engine in did you change the fuel filter?

Edited January 19, 2010 by D_Stirls

[aahh32]

you do have the FPR hooked up to a boost signal? The fuel pressure is checked at idle generally and if the boost signal isn't hooked up you will be losing the extra pressure that you get with boost. If the Fuel pressure is fine throughout the rev range (i.e. base pressure + 1:1 psi with boost pressure) then it has to be either the wrong sized injectors are fitted or the Fuel mapping is out; timing has a slight effect on AFR's but it is only slight not the 4 point difference that you are looking at as nissan factory AFR's can be as low as 10:1 especially when slightly boosted.

What ECU did you use? the one that was in your car originally or one that came with the engine.

And when you put the engine in did you change the fuel filter?

hey mate the fpr is hooked up to the (factory line) well the same line it was connected to on the old engine the injectors are just the standard rb20 injectors and the ecu is the stock one that came with the car not the new engine and no i havent changed the fuel filter?? it looks kinda old was gonna get onto that but didnt know if that could be the problem? also how do you change the fuel mapping?? as jaustech automotive told me that they tuned it and the tune was good?.

thanx heaps for all these suggestions.

[Damo_R34]

also how do you change the fuel mapping?? as jaustech automotive told me that they tuned it and the tune was good?.

thanx heaps for all these suggestions.

every tuner will swear by their tune! and if your not sure how to change your mapping, you definitely shouldn't be touching it, lol. If it comes down to the tune, youll need a good tuner and some dyno time.

[Sinful]

Like the others said...Try another tuner..They should of been able to give you options to fix it...

[Krishy]

haha fair enough

I use and recommend Boostworks, now conveniently located for Norfies at Cavan

i would highly recommend Boostworx....have had my tune done there....awesome guys and know their stuff plus love Shaun's attitude towards tuning and he even was walking me throughout his tune.....only seen the car knock heavily once and that was in the 43 degree weather.....nothing to be worried about at this stage....

[D_Stirls]

hey mate the fpr is hooked up to the (factory line) well the same line it was connected to on the old engine the injectors are just the standard rb20 injectors and the ecu is the stock one that came with the car not the new engine and no i havent changed the fuel filter?? it looks kinda old was gonna get onto that but didnt know if that could be the problem? also how do you change the fuel mapping?? as jaustech automotive told me that they tuned it and the tune was good?.

thanx heaps for all these suggestions.

Unless they chipped the ECU, (which they wouldn't have done if you just went in there it diagnose a fault) they haven't tuned anything. People get confused when they hear "Dyno Tune" because there is no tuning being done all they can do is adjust timing via the CAS. They should call it a "Dyno Check" because in affect that is all they are doing.

Like i said before if the fuel pressure is correct through the rev range then it has to be tune related or injectors.

What effects the amount of fuel is the fuel pressure, injector size and injector timing (fuel maps).

Give my tuner a call; Jeff 0434637357.

He's just a tuner though not a workshop so if it's tune related he'll fix it.

Edited January 20, 2010 by D_Stirls

[aahh32]

Unless they chipped the ECU, (which they wouldn't have done if you just went in there it diagnose a fault) they haven't tuned anything. People get confused when they hear "Dyno Tune" because there is no tuning being done all they can do is adjust timing via the CAS. They should call it a "Dyno Check" because in affect that is all they are doing.

Like i said before if the fuel pressure is correct through the rev range then it has to be tune related or injectors.

What effects the amount of fuel is the fuel pressure, injector size and injector timing (fuel maps).

Give my tuner a call; Jeff 0434637357.

He's just a tuner though not a workshop so if it's tune related he'll fix it.

no they didnt chip the ecu, but he made sure to both say he tuned and dyno'd the car and he also charged me for both aswell as aparently doing the timing but my mate (hes also a qualified mech but he lived to far away to get the car towed to him at the time) said that he could have taken it to a kindergarden and gotten better timing done,

and dont worry there is no way i would try to tune a car myself (repairs and modding etc i can do myself im quite good at it lol)

i just want to get all the little things like the fuel filter replaced before i get it towed back to another workshop for another dyno check.

so lets see if i have this correct unless i have a chipped ecu th fuel mapping should be ok?? and it must be either the fuel pressure above idle or something wrong with the injectors that the workshop must have missed?? maybee i should just replace the injectors, fpr and get it dyno'd??

[Krishy]

just take it to boostworx and have them take a look at it and they will then be able to tell ya whats going wrong and what needs replacing.....as that might be a cheaper option rather replace a whole bunch of parts and finding out that they were all in good working order......

just my 2c

[D_Stirls]

so lets see if i have this correct unless i have a chipped ecu th fuel mapping should be ok?? and it must be either the fuel pressure above idle or something wrong with the injectors that the workshop must have missed?? maybee i should just replace the injectors, fpr and get it dyno'd??

If the ECU isn't chipped then it will be running the factory maps as it is untunable if it hasn't had a cradle soldered in or has a Nistune chip.

If it is running factory maps with factory injectors and running the correct fuel pressure then the mixtures should/have to be correct. If the fuel filter is blocked then it might be letting enough fuel through on idle but as the fuel demand gets higher it won't allow enough flow and the pressure will drop and the AFR's will go through the roof.

Also if i was you i would have paid $165 and bought a new genuine Walbro pump, a R33 pump is at least 12 years old now and could well be as stuffed as the pump that you took out.

[aahh32]

If the ECU isn't chipped then it will be running the factory maps as it is untunable if it hasn't had a cradle soldered in or has a Nistune chip.

If it is running factory maps with factory injectors and running the correct fuel pressure then the mixtures should/have to be correct. If the fuel filter is blocked then it might be letting enough fuel through on idle but as the fuel demand gets higher it won't allow enough flow and the pressure will drop and the AFR's will go through the roof.

Also if i was you i would have paid $165 and bought a new genuine Walbro pump, a R33 pump is at least 12 years old now and could well be as stuffed as the pump that you took out.

i thought about buying the walbro my mate had one of those too, but the 33 pump came out of his 33 and it was in mint condition

and after spending thousands of dollars building this 32 up from the ground ( including buying all new tools, engine crane and stand, mostly all new parts etc) i was running out of cash and i had also just outlaid cash for a ?tune and timing? the shop didnt do, but i reakon going on what i have spoken to people about and the replys on sau im guessing it will be the fuel filter (its the old fuel filter from the old engine) so ill just replace that (with a new one ) and ill book it in for another dyno run to check the afr's.

thanx heaps for all the help guys and girls.

by the way just over the last week i think the modding bug has caught me again , lol so much for having a close to stock daily i will probly end up building another beast as ive already started sourcing some new parts.