The never ending R31 fixup

[Winnie256]

So i bought an R31 with a mate, it was a bargain, $500. Paint is questionable, interior is liveable, and the NA auto 30 has been swapped and plated for a manual RB20.

Good bits:

RB20 Silvertop
Manual
lowered springs
LSD
Zero shaft play on turbo

Bad bits:

Rb20 Silvertop
roly poly suspension
"custom" interior (door cards feature 3mm thick checkerplate)

when we got the car, there were infinite exhaust leaks, coolant leaks and assorted small issues. One weekend we replaced all gaskets and fluids, the car was now driveable. the only issue being that it was power less. Makes 10psi and comes on boost like a stock turbo should, but it doesn't accelerate any faster after about 2000rpm. It would take a solid 20-30 seconds to prime, so we replaced the fuel pump, someone suggested the cat was blocked so we knocked it out. The thing still makes no power.

The only things that come to mind to check is timing and a compression check. has anyone had a similar problem or have a fair idea of what it is?

also, pics to follow when i get some that aren't blurry phone pics.

EDIT: powerless, meaning it loses badly to a stock auto focus. starts to build power then just plateaus (sp?)

[Mr Ed]

Do you have an overly restrictive exhaust and/or intercooler setup on it?

[Winnie256]

The intercooler is a front mount, the kit looks like one of those "no holes" kits, the manifold runs to the passenger side as normal, then the piping goes along the front to the drivers side and into the cooler, back across to the passenger side and into the turbo. The exhaust looks like a 2.5" job, with a non-straight through muffler.

the previous owner said that in its current setup the car used to be decently quick. but lack of maintenance on his part has led to its falling apart.

[Mr Ed]

Sounds decent enough. Reason I asked is because I had a similar problem on my 2JZ-GTE converted GA70. I originally had it hooked up using stock GA70 exhaust/intercooler, which would be smaller than stock for the 2J. After those systems were replaced the problem disappeared.

[fat910]

I'd offer to look at the issue for you but that takes effort. A few little things you can check though. Put a fuel pressure guage on it, just so know your pressure is right. Check the timing, maybe someone had a few too many cones when timing the thing up.

[WildZero]

Silly thing that you've no doubt already checked, but no boost leaks?

[Winnie256]

Silly thing that you've no doubt already checked, but no boost leaks?

well the gauge goes up to 10psi, so we haven't really looked into boost leaks. almost sounds like there is a slight leak somewhere, as there's a bit of high pitched noise under boost, but we really haven't wanted to touch the cooler piping, as it uses about 10 different silicon joiners and a combination of factory plastic and steel pipes.

I'd offer to look at the issue for you but that takes effort. A few little things you can check though. Put a fuel pressure guage on it, just so know your pressure is right. Check the timing, maybe someone had a few too many cones when timing the thing up.

running it without the cat it reeked of fuel at idle. don't really know anyone with handy access to a fuel gauge, but like you said, that takes effort. its getting harder and harder to care when we are getting nowhere.

Timing i definitely want to and am able to check, just need to look up the info on locking it to timing mode and whatnot.

[Winnie256]

What do you mean it takes 29-30 seconds to fully prime? What happens when it is hard to start?

The pump would just whirr and whirr loudly for a bit before startup. its quiet and quick now with the s15 pump

This is what RB20s go like

Most important bit of info...has it ever run ok? When did it start playing up? Anything happen or change around that time?

You mentioned flames, what happened there?

Apparently it has, but after that it developed an exhaust leak (manifold studs were snapped and turbo>manifold gasket was blown out). the previous owner was clueless about cars, and it probably only did about 10000ks in the year he had it, never serviced it either.

On gear changes with the exhaust leak there used to be a bit of a pop then it spit a tiny flame out the tail. didn't do it all the time, but now that we've knocked the cat out there is a distinctive bang sound when changes gears at high revs. haven't driven the car too much so i'm not sure if it still spits flames. (i'd take a punt and say it does).

It's running an atmo vent bov, so that would semi explain the richness between gears.

I pulled the afm out last night, gave it a bit of a blast with some brake cleaner, i have a question about the hot wire, is it the same thickness all the way through? because my wire bulges out a little across the middle (exposed) section. didn't really have the time to pull it apart and try and clean it properly without breaking it.

after the clean it felt like it did go a bit better, but i don't drive the car that often so its hard to tell.

the only other thing to note is that while rolling to a stop i clutched in and the revs dropped down and it ended up stalling as i rolled to a stop. when i started the car again it smelt a bit fuely. almost smelt like an outboard motor.



my skyline is the one with the chev badge on the side. i wanted to swap afm's with a mate but he's running a Z32 unit.

EDIT: re reading this my typing is shithouse. everyone just pretend that english is my second language.

[niggerjewz]

Wow Winnie, your skyline is a beatiful example ! Does it have a LS1 or something?

That coupe looks like it could be quite nice with a bit of work though. You seriously don't get hassled by cops with the cooler handing out and your car looking like it just rolled out of the wreckers?

I think i need to move back to tville and get my bogan on!

[Winnie256]

Can barely see the cooler on mine? so i'm not sure what you are on about there. I never get pulled over because i never drive it.

unless you are talking about PrivateAlphas car, and no, i don't think he gets hassled much. both cars are modplated and reasonably tidy in the engine bay. mine just has ghetto paint. Two owners back it got its current paint job and hektic interior. i guess the owner never got round to finishing it.

EDIT: also, mine has venetians so its obviously an old folks car

Also has GTR sprayed on the front too. HTH

[Privatealpha]

The better car is that corolla just sticking out on the right.

[fat910]

The pump would just whirr and whirr loudly for a bit before startup. its quiet and quick now with the s15 pump

That is the only thing good about the whole car now.

[Sketchy]

Check all your vacumn hoses. My TD navara did the same thing recently, made all the right noise but no go. Turned out to be a manifold vacumn hose had popped off. Fixed it, car is stronger than ever.

[Bren]

Also what kind of intake pipe is it running from the air filter to the turbo? The factory rubber ones on RB20's can have a habit of getting "sucked" closed when they come on boost.

[Winnie256]

Also what kind of intake pipe is it running from the air filter to the turbo? The factory rubber ones on RB20's can have a habit of getting "sucked" closed when they come on boost.

just the factory one, and yeah it feels a bit soft... there's also a bit of a whistle when on boost, which i had assumed to be boost leak, but in either of those cases it wouldn't hold a steady 10psi? and that wouldn't explain sluggishness from idle.

took me ~20-30 seconds to get from 80 to 100 in third. pretty sure we are just gonna get rid of this car, but we'll see.