The deal is, I removed the intake manifold from my CRX to easier remove the block plug (installed a catchcan) I removed a vacuum box, and reinstalled everything. When I first started the car the 3 bar didn't have a good enought vacuum source, so it ran like crap. I moved the vacuum line, and the car started and ran fine.

On the first test drive I gradually accelerated into boost and the car started breaking up, so I checked the plugs and saw that they were black, I guess from the MAP sensor vacuum not being enough, changed the plugs, test drove again, and it's STILL breaking up. Any ideas? Car was fine before, not one hiccup, what am I missing?

Car is tuned on Ectune, 3 bar, 1000s.

 

plug gap? really rich? possible bad coil?

 

I am thinking a plug issue, it clears up after the initial break-up. I'm gonna mess with the gap, and come to find out, it was tuned with a different plug, I have always ran NGK 3330s, and apparantly the car wasn't tuned with those.

 

if it happened after you re installed the manifold then the problem is something in the manifold. you probably have a vacuum leak. 99.9% chance

 

I was thinking that, but just driving around it drives perfect. I will have to look when I get a chance, WG, BOV, and MAP vacuum is all coming off of the IM ports if that helps. It's a Gen 1 Skunk 2 mani. Both vacuum ports are close together, maybe I need to move the lines around? The MAP vacuum is before the WG and BOV.

 

Do you have a wideband oxygen sensor on the car ?
If so, what are your air fuel ratios ?

If you don't have one, get one.

 

i think you need a better vacum source one my friends had the same problem and he also installed a 3 bar map sensor.

 

As long as the Map has its own dedicated port and not Tee'd off something there should be no issue. I would think if you had a vacumn leak you would notice the car idleing differently, I know my car acts alot different with just the vacumn reference for the FPR disconnected, that leaves plugs, air/fuel or coil IMO

 

MAP has its own port, and the car idles perfect. I'm gonna try the plugs I guess, if not I will have to find a wideband. I didn't do anything the change the A/F is my only issue.

 

Does your tach needle jump around at all?

 

Not at all.

 

did the weather change where you live? if so then that alone can change your tune.

 

Not really. I am convinced it's something that I did, because it was fine before. My money is on the plugs, I guess that will be the next thing I do.

 

Just because the car idles fine does not mean there is a vacuum leak. If the car does not spool fully and starts to pop there is a vacuum leak somewhere.

also, check to make sure all of your injectors are plugged in.., my one plug was not plugged all of the way in on my brothers car and it would boost 1/2 way and break up bad.

 

Thanks. I will look into that.

 

whats the temps around where you live? wat was the temp when the car was tuned? and where is your temp gauge when your doing your pulls.

The only reason i ask is because you said your plugs where black, in the winter time my car runs super rich when its cold, it'll foul a plug pulling out of my driveway if i dont let it get warm up. But once it warms up it runs like a champ