I am trying to figure out my friends car. A little back ground the best I can remember; It's an 82mm lsvtec t60-1 turbo, fully built, hondata s300 version 1.4.2. Car has never gone lean in its life, it has always been too rich or perfect high 11's afr in boost, while driving it on the street gettting on it. We took it to the track over a month ago and on low boost (11-12lbs) it ran really good, running a 12.4, with afr in the high 11's. 11.4 to 11.8's. Went to go on high boost (16psi) and fried the clutch. (act 6puck sprung)

We put in my trans, his third gear was grinding, and my comp. stage 5 4puck clutch. Also put new ngk bkr7e plugs gapped to .028. Went to the track to run again, trying to get ready for ifo. Coming out of the whole it would fall flat on it's face, get it into second, then third and about 6000rpm's the car would just fall flat on it's face. After that I just putted down the track. 2 total runs and the same thing. Nothing looked abnormal on the datalogs. Afr's were good, temps were good, only thing that looked weird was at about 6000rpm's it looks like a ripple, something I'm not used to seeing. Unfortunatly I don't have the data logs from the runs.

During the ifo that sunday someone had their water temp sensor go bad, so they borrowed one from my friends car, so they could continue the race. Whether it was a coincidence or not, after that time when I decided to drive his car on the street to try to figure out the previous problem, it started to go lean in boost (13's a/r). Decided to go to the track, added 20% fuel on the second table in boost (16psi). It would build boost on the 2step in the pit (6-8psi), but when I went up to the water box , no boost. I decided to ease into the start and then gradually increase throttle. The whole way down the track I never got into 100% throttle, and just kept messing up, also not building much boost. Also going extremely lean 13+ a/r. Gave up and went home. Besides adding fuel that day I had never previously gone into the computer to change the tune, just to datalog.

Well today I thought that I would mess with the car. Thinking it might be spark blow out, I replaced the plugs with ngk vpower 7, gapped to .025. Reloaded his original map into computer. Put a good working temp sensor from my car to his car. Went out tonight to see if anything changed and it would go past 6000rpm, up to about 8000, without it breaking up but the afr's were still lean. Pulled over and added 20% fuel in boost, low table and high table, just to be cautious. There was no change at all what so ever, pulled over again. Added a little more fuel and then it started to do what it was previously doing, falling on it's face, breaking up in the upper rpm's. Drove home, pulled the plugs thinking that maybe the aem wideband wasn't reading correctly and washing the cyclinders, but the strap was completely white.

I'm at a complete loss of what it can be. Here's what I've been thinking, with the limited knowledge I have.

O2 sensor going bad, even though owner said it's fairly new.
The new hondata software (1.4.2) is messing it up, because when it was running fine I was on 1.4.1
My computer is messed up
His ecu could be messed up


Any help or legitimate answers would be really appreciated.

 

Fuel pressure is dropping.

 

bad 02 sensor.

 

make sure you dont have an exhaust leak before the sensor giving you a false reading

 

Never thought of that. I'll try and see if I can hook up a gauge to it and find out. I guess it could also be the fuel pump.

I plan on puttin my o2 sensor in and see if that might be it. That was my next step. I'm going to try to do everything one step at a time so I'll know what it was, if things get fixed.

Thanks I'll check all nuts and bolts up to the o2 sensor.

 

Boost leaks? My car wouldnt hold boost up top and the AFRs's were bouncing all around the place when I had a small leak at the turbo. Fixed that and its a brand new car.

 

Well the afr's are lean from part throttle in boost to full throttle in boost, no matter what rpm it's in.

 

Well I put my o2 sensor in it and it would only read 14.7,14.6 to 15.3,15.4 when letting off. Thats it, wouldn't ready anything else. And it was working on my car perfectly when I parked it a couple of weeks ago.

 

You are having fuel pressure dropping off. what fuel pump are you running and what fuel regulator? Had a B18 built on a 35r on the dyno about three months ago doing the same thing. Thought it was the regulator so we threw a new one on with no prevail.That left only one logical answer, fuel pump. It was getting weak and around 20 pounds of boost the pump couldnt keep up and fuel pressure was dropping considerably. Put a new one in and all was golden. Hope this fixes it

 

Like the other guys stated it sounds like fuel pressure. I had a similar issue when i went to get my car tuned. Tuner kept adding fuel and it still was running lean. Pulled the vaccum line to the fpr and no fluctuation on fp. Replaced the regulator and that fixed the problem. Good luck!

 

Are you pulling your plugs and reading them? That right there will tell you what its doing, that way you can rule out the wb being bad or good.

 

When I took out the plugs yesterday they looked really good but from driving around last night, after putting fresh plugs in, once I started to figure out that adding fuel wasn't doing anything. I went home and parked it, pulled the plugs on #1 and #2 and the strap was completely white. I am by no means an expert at reading plugs I'm just trying to learn.

I cleaned up his o2 sensor a little bit and put it back into his car. It still reads like it originally did, sweeping from 12's to 15's really fast. While his car was running I turned off his fan, which is normally on all the time, and I noticed some kind of noise. It's going to be hard to explain but kind of more like a metal rattling/spinning noise. And it kind of sounds like it's coming from the front of the motor (cam gears, water pump, tensioner). That's when I noticed that his timing belt seemed like it was a little loose. So I tried to tighten it up, and it did a little but not as much as I would like. I then checked to see if the cam gears where lined up correctly, and they were, then I checked the crank pully and to me it seemed like top dead center on the pulley was off a tooth on the gear compared to the timing mark. There's no front cover so it has to be eyeballed. I think I'll try to have someone else come over and take a look, for a second opinion. And I'll go from there and also check the fuel pressure.

On top of this I have been tracing unknown wires, burnt up old wires, weird cables, rewiring things, in between trying to figure out the other issues. But I like trouble shooting electrical stuff, so to me it's fun.

Thanks for all the help so far. If i figure it out I'll post it up. Meanwhile if anyone else has any ideas I'm open to hear them.

 

I didn't read through all of what you have done but I just went through the same problem and found I was only getting 6VDC to my pump and causing me to lean out up top no matter what I did. so a new pump later, and a regulator and found a voltage drop to be at fault. my fuel pressure was at 30spi and would go down from there.

 

I had the same problem with my car. It ended up being the fuel pressure dropping off because of a crack in the vacuum line going to the fpr. Basically there was a boost leak which caused no pressure to be applied to the fpr.

 

Sounds like a big concensus for a fuel problem. SMOOVY: where did you measure your voltage to find out the volts were dropping? I would assume at the pump.

I would like to add that before this motor, his car was able to boost up to 20psi. And after a rebuild he could only get 16psi out of his boost controller no matter what he did. There was a crack in his manifold at the wastegate they found later on, which was replaced with a brand new one. With that, the car still had problems not boosting past 16psi. Before we had a chance to try to figure out what was going on with the boost, all these other problems popped up.

Is there a way to find a small boost leak? Can you use soapy water to find a leak, whether it's in a vaccum hose or a coupler? I know I could make shift something to put air into the charge pipes to find a leak there but that doesn't help when it's a small leak.

 

Boost leak test will definitely still help if it's a small leak. That's how I found a 1/8" crack in my vacuum line going to my fpr.

 

Could I ask how you performed you "boost leak test"? so I can try it out. thanks