Running probs please help

[houghy_1]

Hi guys,my R's been back on the road for a couple of months now after being off it for 18 months.
The problem ive got is its running really badly when i put load on it to accelerate when its off boost and its also not boosting past standard.
Also when i dip the clutch when coming to a stop the revs can sometimes drop to 6 or 700rpm
I know its hard to explain but i think thats the best i can come up with.

My set up is pretty standard: R33GTR FMIC,Dawes Device(yeah i know it will go eventually),Walbro fuel pump,Denso IK24 plugs,Mongoose.

So far ive replaced the HT leads,Dizzy Cap and Rotor Arm and Lambda Sensor.
Ive also had the timing checked and reset as i was told it was waay too far advanced.
Ive also been told by another garage on a basic code check the the Lambda wasnt switching or something(so i cahnged it,no real improvement) and he closed the gap on my plugs,probably to make himself feel like he'd done something,as he said the spark can be blown out at high revs. Not at 1 bar it cant lol.
Also tried a different ECU nad not much difference.

I havent got a lot of money to throw it at a garage and say fix it atm so im trying it myself.

The next things i can think of are fuel filter,plugs,dizzy and injectors.
Could i also have a problem on the tubo side of things in the actuator???

Any help is greatly appreciated as im planning on rewarding my R with a trip round Silverstone at Trax.

 

[Fast Guy]

Have you done a fault code check?

What was it off the road for?

What gap has he set the plugs too?

New plugs and fuel filter would be one of the first things to try changing.

Try sticking some injector cleaner through it as well.

 

[GTiR-Aholic]

Have you checked your vacuum pipes? also the fuel lines for any leaks?... my fuel line goin to the FPR was leaking causing my R to splutter on full throttle.. had to drive like a grandad everywhere and wouldn't clear it's throat even if I tried to force it.

Did you replace leads with Magnecors? Original OE leads or copy?... I had a customer come in with a polo with a bad missfire.. changed her leads and it was the same but she had bad compression on 1 cylinder too so i rebuilt her head changed a few valves etc.. put it back together and her compression was perfect but still random missfire.. so i put 1 of her old leads back on and hey presto it worked - turned out the copy leads were just as bad as the broken ones!!!

 

[GTiR-Aholic]

Also worth maybe taking your injector rail out and turning it over to see if they are spraying well or if any are clogged up. and agreed change fuel filter

 

[houghy_1]

Fault code check was my 1st job- 55 all clear so that rules out the MAF

It was off the road due to changing fortunes

Dont know what the gaps been set to.

Im probably gonna put another set of plugs in and change the fuel filter.

As for Injector cleaner,it wont hurt.

Everything replaced with genuine Nissan parts,no crap copies for my baby

 

[Fast Guy]

Fault code check was my 1st job- 55 all clear so that rules out the MAF

its running really badly when i put load on it to accelerate when its off boost and its also not boosting past standard

No it doesn't. The maf can still have problems that don't show up on the code check. Bad earth springs to mind.


Is your problem on boost or off boost? You might have a small air leak somewhere.

 

[GTiR-Aholic]

Is your problem on boost or off boost? You might have a small air leak somewhere.

Maybe get a can of easy start and whilst the car is started.. spray it around ur intake manifold, throttle and the pipes.. if your revs sky rocket then you've got an air-leak :doh:

...Although you would have an unstable idle with such an issue..

 

[red reading]

dump valve?

 

[nismoboy]

dump valve?

ditto

 

[houghy_1]

No it doesn't. The maf can still have problems that don't show up on the code check. Bad earth springs to mind.


Is your problem on boost or off boost? You might have a small air leak somewhere.

Oh ok fair enough ill check earths, it happens off boost and on boost.
It can run ok but not hold any sort of boost,then it can really bog down and not come on boost and run like crap after that,even struggle to keep moving unless its on light throttle!!???

dump valve?

I never would have thought about that one,i have thought about air/fuel leaks also so thats another part to check through.

Ill be getting some more parts (plugs,fuel filter and injector cleaner) over the next couple of days and ill concentrate on looking for leaks.

Thanks...for now

 

[houghy_1]

Small update...
Well a new Fuel filter has been fitted and i also renewed the fuel feed pipes as the pipe to the filter was perishing and weeping very slighty.
Injector cleaner tried also.
Still having the same sort of running probs,also doesnt boost past an indicated 9psi on the aftermarket boost gauge i have.
Ive got another couple of R's local so i can swap parts to eliminate things where possible,if they let me

Different dizzy(2nd hand off here) and new Denso IK24 plugs are on the way this week.
I'll also try blocking off the BOV pipe as soon as i find something to block it off with,or make something at work.

I'll probably be back asking for more help this week

 

[campbellju]

The problem ive got is its running really badly when i put load on it to accelerate when its off boost and its also not boosting past standard.
Also when i dip the clutch when coming to a stop the revs can sometimes drop to 6 or 700rpm.

All 3 point towards an air rather than fuel issue. This could be a physical leak or as Carl suggested it might be bad earths or an electronics funny. Grind/rub down your contact on the ECU earth and MAF earth so you get a nice clean contact.

I would also remove your Dawes device to eliminate that culprit from the off boost situation.

Check all your inlet pipes again for leaks. Check you inlet manifold for leaks.

Good luck,
Jim

 

[d2wul]

I have had the same prob for over a year the only thing av got left 2 change is the loom from the ecu

 

[houghy_1]

I have had the same prob for over a year the only thing av got left 2 change is the loom from the ecu

Gutted for you fella,i need to get mine done before Trax!good luck with it

All 3 point towards an air rather than fuel issue. This could be a physical leak or as Carl suggested it might be bad earths or an electronics funny. Grind/rub down your contact on the ECU earth and MAF earth so you get a nice clean contact.

I would also remove your Dawes device to eliminate that culprit from the off boost situation.

Check all your inlet pipes again for leaks. Check you inlet manifold for leaks.

Good luck,
Jim

Hi jim,what would your suggestion be to replace the dawes device as ive not got a proper boost controller yet???

I'll have a look at the earths situation,wheres the ECU earth though?
I know the ecu is in the cabin cos ive tried a replacement ecu.

 

[campbellju]

Just remove the Dawes device completely as a test. The car will obviously only boost to 0.7bar but it will rule out whether its causing you any problems off boost. and idle

The ECU earths are the two attached to the front/top of the inlet manifold (Not obvious). One of my mates thought he would copper slip those to improve their conductivity not realising it is an insulator and the car wouldn't even start! Check the Earth link from the engine to the body shell (At the front of your engine near oil seperator). Also do the MAF earth too. There are other earths on the car but those are the main ones.

 

[Mr GTiR]

Have you checked all your rubber hoses on the inetcooler?

 

[houghy_1]

Have you checked all your rubber hoses on the inetcooler?

Yeah,well the ones that join the hard pipe run inside the engine bay,a few of the mikalor's were not very tight at all so i retightened them all.

I'll have a look at other things that have been suggested friday afternoon as my R is now at my mums house a few miles away for protection,there tar spraying the road outside the house.

Thanks again.

 

[darkyGTI-R]

Good luck with it mate does your head in when they don't run sweet!

 

[Mr GTiR]

I would suggest checking the houses that connect to the intercooler as well. What I mean is physically take them of the car and inspect them inside out and check for cracks and splits.

Did you bypass the bleed valve to see if it would hit stock boost / psi?

 

[houghy_1]

I would suggest checking the houses that connect to the intercooler as well. What I mean is physically take them of the car and inspect them inside out and check for cracks and splits.

Did you bypass the bleed valve to see if it would hit stock boost / psi?

Will do mate,as much as i can be bothered anyway before i just say "sod it!" ands throw at my local garage.