modified 3.0 w/ carbs way down on power/ any help/ideas appreciated (kind of long)
 

OK,

I just had the gearbox rebuilt and got the car back together so I took it out to an SCCA auto-x practice day. Everything started out fine considering that it had been at least 5-6 years since I drove through the cones

I started having carb issues. You know the ones where you end up with the white crusty stuff in your idle jets. I clean them out from time to time and continue to run. Eventually I decide it's time to head home.

When home I blew out the jets again and drive it and it's just way down on power.

It feels like a 2.0 T instead of a beefy 3.0 w/ Mod S cams etc. etc.

I pull the carbs off take out all the jets, e-tubes, air adjusting screws - everything except the the chokes and mixture adjusting screws. -scared to mess the mixture screws since my weber tuning skills aren't the best.

I cleaned out the float bowls (lot's of white junk) blow carb cleaner through all the passage ways and then blow through with compressed air.

The car seem to run well when I rev it up. It sounds like all 6 are firing, sounds good and runs decent but when driving it and you get up in to the power band there's nothing! It's like the cams aren't coming on.

It feels like a 2.0T instead of a Built 3.0 w/ Mod S cams etc. etc.

I didn't check the float level but I don't why that could suddenly change. The accelerator pumps seem to be working right. I did a valve adjustment while the engine and trans was out a couple months ago.

What should I check? Where should I look?

What can suddenly change that affects the cars power so much?

I think the first thing I plan on doing is to check the float level but again, I'm not sure why this would change all of a sudden.

bump to the top for the Monday morning West Coasters.

Nothing was changed on the motor? It was just in for the gearbox? Did you change any gears?

no nothing changed in the motor. I shortened 4th and 5th and that jus made it more lively. LIke I said it was running well and now it isn't. It just seems to kind of bog down at the upper RPM levels while under load. It sounds great just revving it up in the garage...

Sounds to me like you need have your AFRs checked. If they check out, then it has to be tranny related.

hmmm, I'm not sure how it could be trans related. The gearbox shifts well and doesn't make any noise.

I hope it is AFR that is the culprit and that nothing internal failed or changed. I'm just now sure how the AFR changed on me...

The ways it might be tranny related:

Bigger diff put in by accident
Taller gears put in by accident

OK, So I'm clear I didn't just drive it after the trans rebuild and say the car feels slow. In fact the new gears livened up the car. The car could grab second gear rubber and pulled hard all the way up to 135. ...new synchros etc. etc. etc.

It was running good unit I started picking up the debris in the idle jets. After clearing them out it is still way down on power. I am hopeful that nothing internal was damaged and curious as to how the AFR could change without really touching anything. I checked the floats and they don't seem to be leaking or anything.

I guess I'll double check the float bowl measurements. -that's all I can come up with. I'm just unclear how that suddenly changes after driving at an auto-x after being set correctly.

I suspect clogged passageways within the carbs. not just the jets themselves.

Hey Jamie,

I tore them down and sprayed carb cleaner and compressed air through them. Everything seemed clear.

When I tore them down the only things that didn't come out were the chokes, the air mixture screws and the accelerator pumps. ...well I left the throttle shafts in too.

I couldn't easily get one of the covers off to inspect the progression circuit for one hole but the rest looked clear.

It screams like a banshee while reving it in the garage at high RPM. I need to mess with the idle air screws to tune and balance them. It is running a bit rich. -smelly and some black smoke.

.

Rich = Less power. Counterintuitive? Yes. How vigorously did you clean your jets? Know anyone with a LM-1?

Just took it for another ride. It's running close to right at the low RPMs but it really bogs on the high RPMS.

I thought I cleaned the jets well. I couldn't see any debris in any of them and I'm about 100% certain it's not in the idle circuit since it's running well down there.

The main jets didn't seem to have anything in them. - I'm at a loss. I don't know anyone with an LM-1. -are they easy to use?

JZ

Just took it for another ride. It's running close to right at the low RPMs but it really bogs on the high RPMS.

I thought I cleaned the jets well. I couldn't see any debris in any of them and I'm about 100% certain it's not in the idle circuit since it's running well down there.

The main jets didn't seem to have anything in them. - I'm at a loss. I don't know anyone with an LM-1. -are they easy to use?

JZ

LM1 is pretty easy to use.

Just thinking - maybe your fuel filter is clogged up. Have you checked it?

Jay, I have an LM1 if you would like to use it. Do you have a bung in your exhaust for the WBO2 to mount? I do not have the tail pipe clamp.

Are you sure the secondary venturies are installed correctly?

Secondary venturi's. Are they all installed properly?

Hehe, I was being facetious. I'm asking if it's possible you augured out the jets and accidentally made things too rich. It's easy to do. If anything were clogged and you were going so lean as to lose power I would think you'd have detonation.

good fuel pressure and the guage is downstream of the filters. Accelerator pumps are putting out good volume.

I double checked the secondary venturis and they were installed properly and re-installed properly.

the ssi's do have a bung and Thanks for the offer, I'd love to give it a try. I'll send you a p.m.

---ahh got it. Guess I am a bit slow. I didn't use any reamers to clean the jets so I don't think I opened them up. I simply sprayed some carb cleaner through them and some air.