KhanArtisT

iTrader: (2)

I just put an engine in which I was told was a massive street port, I started it about two hours ago and its pulling ~10" of vacuum at a 1000rpm idle. I just did an emissions removal so it may be a vacuum leak. How do rebuilds with used housings run under 1000 miles?

Specs on engine:

S5 NA 13B 6 port
Big streetport (intake/exhaust)
TII housings, used-some chrome peeling
RA (classic seals) "Basic" rebuild kit
Stock turbo/boost setup

The car pulls so little vacuum that the brakes are hard to apply...oil pressure is good, water temp is good (~190 cruise/180 idle). Its somewhat hard to start, as in I have to keep the starter cranking and give it gas once it gets enough fuel/spark. Do I just need to let it run for a while?

arghx

iTrader: (3)

Build yourself a pressure tester to test for vacuum/boost leaks. I bet you have some. You can get one from www.boostpro.net/prodtester.html (universal tester) or easily make the same thing out of hardware store parts. Then you need a reducer coupler and at least a cheap air compressor. That tool was invaluable for me when I did some emissions removal and redid some vacuum routing on my T2.

did you measure the edgewear/chrome flake on your housings? I thought there was a spec for that in the Haynes manual, I can't seem to find it in the FSM, but I remember seeing a spec somewhere. What was your side seal to corner seal clearance? or are you saying got the motor from someone else and that person told you it had chrome peeling?

Aaron Cake

iTrader: (1)

It depends on what "massive street port" means. 10" of vacuum at 1000 RPM is in bridgeport territory, to give you an idea of the porting necessary to pull that little vacuum.

Sounds like you may just have a large leak.

Or something is wrong with the engine.

A port job that big would most certainly create a bridgeport-like idle.

KhanArtisT

iTrader: (2)

Buying an air compressor as much as I'd like to would be unpractical but I'm going to do the carb cleaner test today. I didn't measure the chrome peeling on the housing, I had no idea you could even do so, no idea on the clearance, and I bought the housings used and gave them to my engine builder who did everything.

I'm really starting to think its the oil injection "vacuum" lines...since I tee'd them into the double throttle diaphragm (A/T) line that runs under the TB and before the throttle plates...ALL other nipples (including the one the spider probably connected to) on the TB are vacuum only.

KhanArtisT

iTrader: (2)

So it put out 60psi on every face, F/R cold. Thing won't even start now, its not flooded because theres no oil on the plugs. I checked for fuel leaks with a pressure tester and it holds 36psi after fuel pumps been turned off dropping 2psi every 2 minutes or so. It'll probably start if I keep messing with it but what the hell...

Are those normal compression numbers for a rebuild with used housings and RA classic seals?

cmanns

60 psi dont sound so good..

AlexG13B

iTrader: (7)

how did u check compression exactly?

arghx

iTrader: (3)

don't freak out about the compression just yet. fix the vacuum leaks.

SonicRaT

iTrader: (6)

Push start it and drive it like you stole it?

KhanArtisT

iTrader: (2)

yeah it starts good now, just takes a lot more cranks and I have to give it gas for the first few seconds.

I drove it too it runs good, good drivability, OK idle, still crappy vacuum ~15" @ 1500rpm. I'll drive it for a while and see if it gets better. I used the whole carb cleaner bottle though, theres definitely no vacuum leaks.

Compression check was from the gauge I rented from Autozone, mine had a huge leak in it. For some reason the check valve didn't work and it gave me each reading. Maybe it was leaking, who knows since I let it rest on the alternator and watched it from inside the car.

arghx

iTrader: (3)

how is your idle being adjusted? are you just pulling the throttle cable? turning the throttle stop screw? adjusting the BAC valve screw?

will the car idle if you try to drop it down closer to 750-850?

KhanArtisT

iTrader: (2)

The BAC is disconnected (no port on TID) so its being adjusted through the throttle cable, TPS screw and throttle stop screw. I haven't tried to bring it lower than 1000 since it'll likely pull less than 10" of vacuum which isn't even enough to assist the brakes.

Aaron Cake

iTrader: (1)

There should be a check valve in the brake booster line which will keep the booster under higher vacuum even if the engine is pulling low vacuum. It's so you can brake under positive manifold pressure.

KhanArtisT

iTrader: (2)

There is and you do have that one reserve pump after that they start to get weak. I guess I can live with it for now though. The idle is really moody and low speed drivability really sucks, lots of bucking under 3k. Cold (overnight) starts suck too, a lot of cranking. Thank god for my optima yellow top. Water temp stays at a solid 195*, oil pressure is good so far.

ITSWILL

iTrader: (12)

are you using old spark plugs by chance, if so that could be the problem. Otherwise i would say you have a vacuum leak, although my street ported engine had about 15 pounds of vacuum at idle as well, but I did recently find that my BOV was leaking.

KhanArtisT

iTrader: (2)

Yeah I'm using old plugs...but they probably had less than 100 miles on them. They're BUR9's though maybe thats the problem.

arghx

iTrader: (3)

Your housings are probably barely acceptable and your side seals kind of worn. It may just take a while to break in, and don't be upset if it doesn't make as much power as you would have liked.