swapped intakes, now engine smokes like crazy out the exhaust

[lowthreeohz]

i converted my buggy to tbi and after changing the tb/tbi it smokes like a fucking champ at anything over mid throttle. with no load i can blip the throttle up to maybe half and it pours a cloud out. it smells strongly of oil and some unburnt fuel.

Compression numbers were 180-176-180. stock is 200 and min spec is 150. The PCV was replaced yesterday - the old one was stuck closed.

I'm also getting a lot of smoke out of the breather connected to the valve cover. none of these symptoms happened until after i swapped the intake manifold. any ideas ya'll? stuck oil ring maybe?

[FOKAI]

Vacuum leak?

[ktm300hater]

Intake gasket and sucking oil out of crankcase

[lowthreeohz]

The intake gasket was fine when I swapped the intakes. I understand oil is coming from the crankcase into the combustion chamber, i'm trying to figure out how.

[lowthreeohz]

Vacuum leak?

Everything that's not hooked up is plugged.. no sucking/surging, idle is steady, and using an unlit butane torch around all the gaskets doesn't solicit a response.

Could the bad PCV have caused oil to blowby into the chamber, and now i'm just burning off all the crap atfer changing the pcv?

[lowthreeohz]

Anyone got any ideas? I'm home sick all weekend, may as well work on that shit.

[lowthreeohz]

maybe im giving this thing way too much fuel?

stock TBI FP is 22-32psi @ key on engine off
11psi @ idle

i ran a summit generic 45psi pump that is relatively low volume, but now im wondering if it isn't too much for the factory FPR to regulate? if that were the case - can i put an inline fpr before the TB to dial it down to the 32psi the TB is used to seeing? am i completely missing something?

thanks

[shumpertdavid]

Fuel pressure on a GM TBI is 9-13 PSI. I know the stock tbi pumps won't make enough pressure, even dead headed, to make a multiport engine hardly start usually. If it's running overly rich it should be a black smoke generally. I have seen heavy fueling cause white smoke but it's generally been from something like a stuck open injector.

[lowthreeohz]

Fuel pressure on a GM TBI is 9-13 PSI. I know the stock tbi pumps won't make enough pressure, even dead headed, to make a multiport engine hardly start usually. If it's running overly rich it should be a black smoke generally. I have seen heavy fueling cause white smoke but it's generally been from something like a stuck open injector.

Sorry but what is the dead-heading?

So i guess where im confused -is the high end spec with engine off (32psi).. does this need to be the capacity of the pump? or is the 9-13psi pump building up to 32psi when the engine is not running?

and finally, where can i get a universal inline TBI-friendly pump?

i appreciate the reply

[shumpertdavid]

dead heading is forcing the pump to make it max pressure. Usually we do this by blocking the return line or by clamping off the pressure line behind the gauge. It forces the pump to max pressure and can be used to diagnose a weak pump if it can't maintain it. The tbi setup shouldn't make more than 13-15 psi key on engine off (from what I remember). The regulator should keep it from making more, provided the pump isn't overcoming it which I think in your case it is. I know there is an inline pump available that will give you the correct pressure but I don't know the part number or manufacturer. I did an engine swap where we pulley a tbi setup out of a 70 C10 and put in a GM performance parts crate ls based carb motor. The truck was running a stock behind the seat tank with an inline pump under the passenger side of the cab.

[lowthreeohz]

thanks again for the post.

per the FSM it states key on engine off (deadhead?) - 22-31psi
key on engine running - ~11psi

[shumpertdavid]

dead head is not key on engine off pressure, it is when you physically clamp off the return or pressure hose after the pump in order to force it to make full pressure. It's irrevalant in this particular instance so if you don't understand what i'm explaining it doesn't really matter at this point.

I guess now would be a good time to ask what you're running. I just assumed by tbi you were talking about something gm related. If not then my info may be completely off.

[lowthreeohz]

Makes complete sense now, thanks. got some good info on another thread, ill update when its sorted out.

[Skidonenko]

The intake gasket was fine when I swapped the intakes. I understand oil is coming from the crankcase into the combustion chamber, i'm trying to figure out how.

You reused it/them? If you did I would start there before anything else. Look it over closely upon dissassembly. Have you tried pulling plugs to see if you have oil on all or 1 plug?

[lowthreeohz]

How would the intake manifold gasket allow oil into the chamber? It's a metal gasket BTW. ill pull them tonight and see if one looks different