Tuning question

[wrund1]

I just put this carb'd V6 in a Jeep. Now I need some info on how to get it put out some power.

First, I'll tell you what I have:

'79 Turbo 231, not running the knock sensor yet (merely unhooked). 140# + cylinder pressure. 12 degrees initial timing. 14 inches vacuum at idle, idles real smooth. No known vacuum or exhaust leaks (fixed what I found). Temporay exhaust pipe, however, about 24" long, no muffler.

No coolant ran through carb base. No EGR valve. Factory PCV valve. Only one vacuum line. This may be a big part of it. As you look at the carb from the front, the carb base has 3 vacuum ports (besides PCV). I hooked a vacuum line up for the far left port, into the PEVR, then PEVR into the middle vacuum port (right under the primary rods). The far right vacuum port is capped.

I have 14" of vacuum using a manifold port (either one on foot of turbo, or the one in the rear of the manifold). But the far left vacuum port I'm using going into the PEVR reads only about 9-10".

I do not have a boost gauge yet, can't get one locally, need to order one. I rebuilt the carb, I know the primary metering rods go up and down easily, not stuck. Jetted up 2 sizes due to (future) cold air intake and performance exhaust. Secondary air valve has little tension, and secondaries are able to open.

Spark plugs gapped at .060", forget the brand, platinum tip I believe.


Just got it drivable, and this is what is happening- idles fine, but not much power after that. WOT has no more power than 1/4 throttle. No audible knock. Any ideas? It's no more powerful than the gutless 225- 2bbl it replaced.

Thanks in advance.

 

[b4black]

If the Turbo Control Center in place? I bet the distributor is pulling all the timing out because it's not hooked up right.

Do you have a '79 Buick factory shop manual?

 

[wrund1]

I don't have a manual, no. I have the ESC plugged into the distributor, just not connected to the knock sensor. I think I'll hook it up the knock sensor just to see what gives.

With the knock sensor not hooked up, I thought the ESC couldn't retard the timing. Yes / no?

I'm also going to see if the actuator is leaking vacuum, and I see that I have the power valve connect incorrectly.

Any other ideas / suggestions?

Thanks again.

 

[wrund1]

Well I found out that my throttle cable had slipped (custom), thus giving me only 1/3 throttle. I'll post again if the motor still isn't right.

 

[wrund1]

Well, the throttle cable didn't help any, it's still a gutless turd


I hooked up the knock sensor, no difference. It runs fine until about 1/3 throttle, then the motor just doesn't want to pull. In park, it seems like it's leaning out around 2,000 rpms. Seems to fall flat once it hits zero vacuum. It will rev to 4000 rpms in park, but it doesn't want to.

No boost ("0"), either.

 

[wrund1]

Should have said no boost while power braking or driving it.

I'm thinking the primary fuel system isn't working. It's running on the curb idle system, then leans out for some reason.

Feel free to jump in with ideas :wink:

 

[wrund1]

Primary metering rod hanger was stuck down rubbing against the carb gasket. Fixed that, tightened up the bolts from the intake plenum into the turbo.

In gear, still no real power.

In park, revs easily to 3500 - 4000 rpms. BUT the exhaust manifolds glow red hot after a few short minutes (it's dusk right now). Whew! Them suckers are HOT! :redface:


So swap out the turbo and go with a standard carb setup, or is there more to play with?

 

[wrund1]

AHHA!

Bad timing light. My 12 degress initial was really 4 degrees retarded.

Set timing to 15 degress initial (actual), runs sooo much better. 4" more idle vacuum.

It's actually drivable now.

Sadly, still has zero boost. Pops back through the carb when 3/4 or more throttle.

 

[Ttype83]

I would say that your wastegate actuator is not working...no boost, actusator not working..poping thru the carb,,not sure mine just started doing this tonight. check your plugs and the plug gaps.

 

[wrund1]

Actuator has new vacuum hoses, it works when I put pressure to it, did not check to see if would hold that pressure.

With the exhaust finished, and an air cleaner installed, no popping through the carb. Runs great actually, just no boost.

I also have it jetted too rich on the primaries, will go back to original jets.

Plugs are fresh NGK UR5's at .040".

Thanks!

 

[wrund1]

Jetted it back to original. Runs really great. But, still no boost.

Now when I get on it, I hear a vacuum cleaner type of sooner. Not a "turbo whistle" like I'm used to. Sounds like a strange nose, almost like an electric fan turning on.

Exhaust blades spin fine, no play.

Is it possible the turbo impeller (intake side) is bad?