Boost Issues, Where to look first?

[54Rich]

My car has been running great, no issues at all until yesterday. I have the boost set at 22 psi with a RJC controller. All of the sudden 18 psi is the best it will do? I really didn't notice it (Not often I play with 22 psi on the street). I tried to increase the boost with the controller and it will not increase

Scan Master number are good (Nothing has changed from before).

Where should I start?

Thanks

 

[WSLN 6]

Maybe your wastegate actuator diaphram is leaking under higher pressure.

 

[SHADOWII]

Check drivers side header for a crack between #3 & 5.

 

[Ttype6]

My car has been running great, no issues at all until yesterday. I have the boost set at 22 psi with a RJC controller. All of the sudden 18 psi is the best it will do? I really didn't notice it (Not often I play with 22 psi on the street). I tried to increase the boost with the controller and it will not increase

Scan Master number are good (Nothing has changed from before).

Where should I start?

Thanks

You'll need to tighten/shorten your actuator rod.

 

[Fast4Ward]

its better than setting it at 20 and getting 27 to 29# and afr hitting 16:1, 18:1....DOH! ...that's what happend to me the other day. I've now changed the failing pump:redface:

 

[54Rich]

OK, checked the waste gate for leaks, seems good. Checked all connections. Gave the WG two turns, took it for a ride. Tuning these on the street sucks, but what I did see was an imeadiate boost to 19 ish and as I held my foot in it, the boost slowly decreased down to 16 ish?

Everything else is perfect, car still runs strong, I just like what happens above 20 . Maybe a cracked header, it's been welded once?

 

[1fast6]

pull your plugs and check the gap and see how they look.

 

[54Rich]

pull your plugs and check the gap and see how they look.

I pulled one from each side, perfect

 

[theCATman]

You haven't had the WG "Y" hose off for any reason?

If so, coulda put it on backwards??

 

[54Rich]

You haven't had the WG "Y" hose off for any reason?

If so, coulda put it on backwards??

Nope, it's plumbed directly to the RJC Controller, no Y. One day 22 psi, the next this? I'm going to take a good look at the exhaust as soon as I can, to rule that out.

 

[Ttype6]

Nope, it's plumbed directly to the RJC Controller, no Y. One day 22 psi, the next this? I'm going to take a good look at the exhaust as soon as I can, to rule that out.

Disconnect the hose from your compressor housing and plug the fitting on the housing. Carefully give it throttle and see how much boost it makes.

 

[chops]

I had simular problem it was my rjc boost controller I took it and chucked on the roof!!!! Disconnect the boost. Controller and see how it is before. You determine anything good luck!!!

 

[54Rich]

I had simular problem it was my rjc boost controller I took it and chucked on the roof!!!! Disconnect the boost. Controller and see how it is before. You determine anything good luck!!!

That thing is so simple, you wouldn't think it could go bad? I did find that the pass side header bolts were a 1/2 turn from tight, so maybe that's what the issue is? It's sandwiched between the GM gasket, so possibly leaking under high boost. No time to run it last night to see if that took care of it.

I'll run it first then take the controller out of the question. With running just the stock adjustable WG, what would be the max boost I should see?

 

[54Rich]

Well, both sides of the exhaust were a little loose, 1/2 turn or so, maybe I should have left the gasket out? Anyhow, got it tightened went for a little ride. Now it's quite a bit colder today and I'm on my street so I couldn't stay on it long. But instantly to 20-21, that's were the tires want to break loose:biggrin: So I think all is good. At least I got to get under it and go over things, driving it to BG. It's first long trip since I've owned it

Thanks all for your input!

 

[bison]

Well, both sides of the exhaust were a little loose, 1/2 turn or so, maybe I should have left the gasket out? Anyhow, got it tightened went for a little ride. Now it's quite a bit colder today and I'm on my street so I couldn't stay on it long. But instantly to 20-21, that's were the tires want to break loose:biggrin: So I think all is good. At least I got to get under it and go over things, driving it to BG. It's first long trip since I've owned it

Thanks all for your input!

If they werent solid copper gaskets you need to remove them or they will leak or blow out again.

 

[54Rich]

If they werent solid copper gaskets you need to remove them or they will leak or blow out again.

Really? Crap! They are the original GM gaskets, that came in a kit? They have been there for two years now, about 5k of fun miles

Thanks for the heads up