R34 Gtt Surging After Service?

[skyline_seven]

hey guys i have an r34 gtt completely stock and took it to a mechanic and after he gave it a service it is surging when you give it a boot full, i have no idea why it would be doing this any ideas?

[Hanaldo]

Gonna need more detail... What did he change in the service? Define surging, like a sharp cut of power or?

[skyline_seven]

all he did was changed oil, oil filter and few minor things that dont contribute to motor, when you put your foot into it, it has power until about 3,000rpm then starts losing boost but picks up again and then cuts out again, its constant throughout the rev range

[Hanaldo]

all he did was changed oil, oil filter and few minor things that dont contribute to motor, when you put your foot into it, it has power until about 3,000rpm then starts losing boost but picks up again and then cuts out again, its constant throughout the rev range

Could be any number of things from bad fuel, to coil packs to air flow meter to vacuum leak... Very hard to say based on the information you've provided. E-Mechanic isn't an easy occupation.

Did the mechanic do your fuel filter? Does the car seem like it's running rich at all, any black smoke coming out the exhaust when these surges occur? Does it idle nicely?

[skyline_seven]

idles fine and only run 98oct fuel, no smoke at all and i cant remember if he did fuel filter, its the mrs car and the receipt is in her car. it doesnt seem to run rich whatsoever, what oil is best to run in the neo's?

[Moodles2]

Get that receipt, list everything done. Then we might actually be able to help.

RB oil filter changes are notorious for being a complete pain in the ass, a careless mechanic can easily damage a vacuum hose causing the motor to overboost and hit R&R.

[skyline_seven]

ok heres what was done

-change oil and oil filter

-check brakes

-top up fluids

-check lights steering tyres suspension etc

-inspect underbody, hoses, belts etc

the oil that was put in is 10w-40 semi synthetic mobil formula

[Godzilla34]

I always use Penrite fully synthetic you wouldn't think but oil can make a big difference

[skyline_seven]

10w-40 still?

[Hanaldo]

ok heres what was done

-change oil and oil filter

-check brakes

-top up fluids

-check lights steering tyres suspension etc

-inspect underbody, hoses, belts etc

the oil that was put in is 10w-40 semi synthetic mobil formula

This sounds like your issue. I bet he has played around with some hoses and not noticed has has pulled one off or he has replaced one and not put a clamp back on, etc etc. I would just go over all your hoses, and I mean all of them. Unfortunately it's not a fun job on a Neo

As for oil, I personally always use full synthetic as well but it's not realllllly critical. Semi-synthetic will do the job.

[skyline_seven]

This sounds like your issue. I bet he has played around with some hoses and not noticed has has pulled one off or he has replaced one and not put a clamp back on, etc etc. I would just go over all your hoses, and I mean all of them. Unfortunately it's not a fun job on a Neo

As for oil, I personally always use full synthetic as well but it's not realllllly critical. Semi-synthetic will do the job.

ok will check it all out tomorrow thanks alot guys

[dori34]

did he touch the spark/ignition side of things at all?

[B-Boi34]

Did you find out what the issue was? I have a similar problem except mine surges between 4000 & 5000 RPM & then pulls fine from there to redline. It only happens when my foot is flat not at part throttle.

[rondofj]

I had a similar problem AND much less power AND engine shutting off after rapid deceleration or foot off the throttle- problem was a thin broken vacuum hose, just one bloody hose on intake manifold.

[gotRICE?]

Did you find out what the issue was? I have a similar problem except mine surges between 4000 & 5000 RPM & then pulls fine from there to redline. It only happens when my foot is flat not at part throttle.

That sounds like RnR to me. Cold weather, possibly running a touch more boost and maxxing out your AFM.

[B-Boi34]

I thought it might be R&R. It doesn't have a boost controller on it so should be running stock boost although the boost gauge shows about 0.7 bar.

I reset the ECU & also changed the BOV so it was re-circulating again & it seemed to almost fix the problem, now its just a slight hesitation at 4500rpm only sometimes, other times its fine.

The re-circulating pipe isn't 100% sealed so I will seal it all up & see if that fixes it.

[StevenCJR31]

unless the mechanic is a complete berk then he shouldnt of knocked any vacuum hoses off when changing the oil (at least)engine bay is large and oil filter easy to get to when compared to a 32 anyway