2G Possible Intake Restriction?

[AntmanAndLittleDi]

We just went through nearly a whole electrical rebuild on our 1999 Eclipse GST. Replaced turbo, motor mounts, spark plugs & wires, ecu, broadband O2 sensor, fuel pump, throttle position sensor, coolant temp sensor, fuel injectors, flex pipe on exhaust, harmonic balancer, radiator hose, .... thinking there's more, but can't remember. Anyway, long story short, we still can't get the car to stop running rich even after fixing all of these problems. Our neighbor has a scanner that he gladly brings over and runs codes for us which is finally showing no more electrical/sensor problems. While driving it around, we noticed suddenly the O2 sensor was reading about 12.5 when typically it would run 9.5 - 10.5. Rather than assuming it fixed itself, we took it back home, opened the hood and found a cap on the air intake had blown off... seriously blown off, ripped the threads out of the cap. For a temporary fix we put the cap back on and wrapped it with gorilla tape. We couldn't leave the cap off because it is located after the air filters and after the mass air flow sensor, which any dirt would go straight to the motor. After putting the cap back on, the O2 sensor went back to 10.1 at an idle. The air filters are fairly new, put in a couple months before we bought it in July this year and still look very clean. Is there something we are overlooking? As is the car only gets 9 - 10 mpg and it doesn't matter if it's in town or highway miles. Eager to get this baby running like a champ so we can give her a much needed paint job. Any help is much appreciated!

 

[thejollyrancher]

I doubt an intake restriction is your problem. It only ran leaner as a result of unmetered air. Do you have and sort of tuning software? Could this be a tuning issue? How does the car run aside from the rich condition?

 

[synthetek]

There shouldn't be any threaded cap on your intake. It sounds like your bov is not recirculated and some one tried to put some kind cap to plug the intake. Can you post a pic?

 

[jimsgsx]

There shouldn't be any threaded cap on your intake. It sounds like your bov is not recirculated and some one tried to put some kind cap the plug the intake. Can you post a pic?

Exactly what i was thinking!

 

[AntmanAndLittleDi]

To thejollyrancher: I don't have tuning software handy, but I have a cousin who's a certified technician at a shop nearby and a genuine dsm nut. If I need it tuned, it will be all his. Aside from running rich it runs great. To synthetek: Wouldn't surprise me if something was missing or altered on this poor thing. It was being used as a guinea pig to figure out what worked or didn't work before doing the real job on a secondary Eclipse. If it's missing a part, then there should be another port somewhere else? Or another missing bolt-on piece of equipment? I'm borrowing computer time at the moment and left the car at home or I would post a pic of the whole situation, tape and all . See what I can do for you tomorrow.

I think I picked the worst car on the market (being a guinea pig project) to start my beginnings into the dsm world, but I'm a sucker for a car in distress. Thanks for the ideas to look at!

 

[synthetek]

There should be a hose that goes from the bov to the intake, see if that is missing.

 

[AntmanAndLittleDi]

There should be a hose that goes from the bov to the intake, see if that is missing.

Will do when I get home. Going to pick up Antman and probably pop the hood while supper is cooking.

 

[jimsgsx]

Its this hose i drew a arrow pointing to it.

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[mercaholik]

Yea that's your bov recirculation hose, that for sure needs to be connected and leak free. By the way 10:1 on fully warm engine is too rich for idle/light cruise. If your injectors are larger than stock and aren't compensated for will do it. So will too high of base fuel pressure setting, or fpr over run. You should target around stoic (14.7:1) for idle. Be careful here cause cold start air fuel ratios are way richer and it can wash the oil off the cylinder wall (bad). If your running way too rich all the time. You can also check your short and long term fuel trims, how's your ect, narrow band o2?

 

[AntmanAndLittleDi]

Sorry for not reposting for a while, been busy at work. Found out why the car wasn't running correctly, and the more we drove it he worse it got. My dad took it out for a drive to better understand what we were talking about and brought it back running on one and not quite a half cylinder. Pulled the spark plugs and found all except one had burned out and dropped metal and porcelain into the motor. We have it in pieces in the garage at the moment. Block is good, honed the cylinders. Have a whole new head assembly on the way, should be here tomorrow. Plus new pistons with rings and bearings should be here tomorrow or the day after. Buyers be WISE not Warry of cheap parts. We bought those spark plugs because we saw the cheap price and the parts house said they would work in an eclipse turbo. After this mayhem I had my brainy cousin look up the numbers off of the plugs. All of the porcelain numbers said they were for an eclipse turbo but all of the metal numbers said they were industrial, not meant for automotive. Everyone makes mistakes at work so I'm refusing to say what brand name of spark plugs we bought. Just a harsh reminder of "You get what you pay for" Now we have new plugs with matching numbers, lesson learned ! I will post again after we get the poor thing back together. Oh, and we don't have the hose that goes back into the intake, it was just into atmosphere. It will be changed to go into the intake when we are done with the rebuild. Thanks guys!

 

[97 eclenger]

next time, run the ngk copper spark plugs. those are pretty much the best plug to put in the 4g63

 

[AntmanAndLittleDi]

next time, run the ngk copper spark plugs. those are pretty much the best plug to put in the 4g63

That's exactly what we bought, three days after motor melt-down. After my cousin looked up the numbers on the burnt plugs he ordered the ngk for us and highly recommended them. I have pics of the busted up head assembly that I'll post another time, probably just start a journal on the whole thing since we have pictures of the open block and such. Rather than making this into a mile long thread.

 

[pmillerlite]

Like everyone's been saying, make sure you have the bov recirculated and leak-free! Any air lost in the system after the maf is unaccounted for and you will end up with a rich mixture. This topic has been beaten to death a thousand times, my ignorant self vented my bov awhile ago and I was wondering why the car would bog down/stall after shifts so I looked into it as well. Hopefully that does the trick along with your rebuild and tuning

 

[AntmanAndLittleDi]

How do I mark this thread as Resolved? Seeing as we found out what the real problem was. After being rebuilt the afr averages 14.7:1 at an idle and 12.2-12.5:1 under boost.

 

[lasershark]

How do I mark this thread as Resolved? Seeing as we found out what the real problem was. After being rebuilt the afr averages 14.7:1 at an idle and 12.2-12.5:1 under boost.

Above post number 1 there is a tab that says thread tools, click on that then you can edit the title and mark it as resolved.

 

[AntmanAndLittleDi]

Above post number 1 there is a tab that says thread tools, click on that then you can edit the title and mark it as resolved.

Amazingly, I don't see that tab. I thought it was because I was on my phone earlier and waited until I got back home to log onto the laptop, but it looks the same as on my phone. I moused over all the tabs available and tried looking for the Thread Tools section, but it's simply not here. Wonder if Windows 7 has anything to do with it.

 

[lasershark]

Amazingly, I don't see that tab. I thought it was because I was on my phone earlier and waited until I got back home to log onto the laptop, but it looks the same as on my phone. I moused over all the tabs available and tried looking for the Thread Tools section, but it's simply not here. Wonder if Windows 7 has anything to do with it.

It's normally by where it says "watch thread" at least it is on all the threads I have ever marked as resolved. I even went back to an old thread of mine and sure enough it is there on mine... Sorry, I don't know what the deal is

 

[AntmanAndLittleDi]

I don't know either. My new ones have it, but some of the old ones don't. I just posted it into the Problems/Feedback section, see if they have an idea.