Car Feels Sluggish.

[KezR33]

Hey guys, I own an 1993 R33 GTS that's done just over 100,000ks. Apart from missing a fan shroud when I bought the car, the car has run great, until recently.

About two weeks ago the car started to feel... sluggish, for a lack of a better word. Especially when cold. Sometimes when the car is cold it will perform horribly, not that I'm thrashing it, but when I first start it up, and drive down the street it accelerates far more slowly than it used to.

When warmed up, I only notice the problem when I give the car shit. It's fine till about 4000 revs in 2nd gear then the power starts to cut back. Like, the revs will increase uniformly till about 4000-5000rpm and then it will start cutting back, as in, the revs will drop for a split second then pick back up.

The best way to describe would be it feels like the car has been over filled with oil. I once over filled my parents car with oil and it felt very similar. The oil has not been changed since it was serviced (about a month ago), and it is only about a mm over the F bar on the dipstick. I thought it was close enough to be okay, or is it still too high?

Some additional info incase it helps, the oil pressure sits at around 7 on start up, and drops to 4 when warmed up, and the oil very clean.

Thanks for any help guys, if the problem isn't obvious I'm definitely taking it in to get checked out, and as you can probably tell I am not the most car literate person you'll ever come across, although I am trying to learn, so I appreciate any help.

[UNR33L]

my car does the same thing in cold starts. think we need the 100k service with timing belts n that

[skyla]

What grade oil are you using?

I had a problem after an oil change a few years back, my car didn't like the new oil, I changed the oil as soon as I could and the problem went away, but in my cars case the car was just plan slugish through the rev range.

Has the fuel filter been changed since you've had the car? If the fuel filter is dirty and clogged up that can make the car feel gutless

[R338OY]

Fuel filter is important. Fuel pump might be dying as well.

What spark plugs are you using? Make sure they're set to the correct gap (i'd assume for your car it's 1.1mm gap), consider a new set (get NGK $25)

Any leaks in the intake or exhaust manifolds? Check for broken studs on ex. manifold (you'll have to remove the manifold heat shield, easy)

Intake plenum leaks? Look at the studs.

Otherwise it'll help to do some minor servicing -

new oil (expensive usually = better), get the right grade (prob 10w40 i'd say)

clean your AFM (air flow metre, connects to the air pod/box)

Clean your throttle body with carbie cleaner (will help it to breathe)

Otherwise you'll need to get it inspected if these things don't help (they're regular servicing things anyway).

[KezR33]

As I said, it had a full service about a month ago. I bought the car about 2 weeks before that and then had the car throughly checked out, and had the oil and filters changed, among other things.

The place I took it to looked a little dodgy, but the guy seemed pretty genuine and really new his shit when it came to Skylines, plus he was the only import specific mechanic around the Frankston area. In his mind, he said the Skyline was one of the best looking cars (under the hood) he'd seen in a long time, short of the fan shroud. I don't know what oil he used, but I can't imagine him putting a dodgy stuff in. Plus, the car only started playing up a few weeks after the service, not directly after.

The only other modification I've done since then is replace the pod filter. It had a dodgy looking Apexi one in there that I really didn't like the look of, so I swapped it for a 3A Racing one. My mate who's a machinist and fitter, and owns a Skyline himself, put it in for me. He did a pretty good job of it too, put in brackets to brace it down.

Could the pod be messing up my intake?

Thanks again.

On a side note, can anyone recommend a good mechanic around the Mornington Peninsula? I don't mind driving a bit further for a quality job.

[KezR33]

So I took it in to get it checked out, and apparently the muffler has imploded, and it's shooting the guts of it out. So much for a nice exhaust sound.

[Eug]

muffler or a collapsed cat?

normally excessive fuel is the cause.

[KezR33]

muffler or a collapsed cat?

normally excessive fuel is the cause.

Muffler is dead. It's pretty old, probably nearly as old the car. I don't know what you call it, but the inner casing the keeps the steel mesh nice and tight around the edge has deteriorated and the muffler itself was full of the mesh. He suspects the occasional power loss was due to the mesh bunching up and restricting the flow of air, which could've really messed up my engine.

He's removed it all, and the car has run fine so far, so we're hoping that was it. It's really, really ridiculously loud. At least I have a receipt and an excuse for the cops if they pull me over, I hope they buy it.

I do have a question though, anyone had any experience with those adjustable mufflers? The ones that you can quieten down with a remote inside the car. They'd be costly, but I could easily see the value in one.