Slow power loss over one week...

[90 GSX]

I recently installed my full exhaust and the car was running perfect, I mean it was really fast. About 3 or 4 days after I got the exhaust I started to notice the car was getting sluggish. It was moving but it was not pushing me back. Now, a week later, the car is running like crap. I can hear it slightly backfiring when I let off the gas fast or shift under boost. It feels like it's running very rich (smells like it too). The only problem I know of with the car is that the downpipe gasket is slightly blown out (but you can barely hear the leak) but that won't affect 100% throttle anyway. There are no boost leaks, plugs are fine, but I think my plug well gaskets are leaking because there was some oil on the plug boot that comes back even after I clean it. Could that be causing the sluggishness? What else could cause a gradual deterioration in power?

EDIT: I know am confident that the sluggishness and power loss is due to a weak igntion system. After replacing the coil, PT, plugs, and wires, I think that there may be a problem in the wiring or in the cas (could the cas cause a weak spark). When I spark the wire to the stud for the driver's side motor mount I am getting a yellowish spark, when I'm almost positive that I've done the test before in the past and got a crisp blue spark, that made a loud crack when it sparked.

 

[No_Skillz]

No boost leaks, huh?

 

[95blackGsTurbo]

Check for boost leak's then check your o2 sensor to make sure it is fluctuating like normal.

 

[90 GSX]

There are ABSOLUTELY no boost leaks at 20 psi. I used to always blow off this one elbow but I got a 2.5" minimum t-bolt clamp and that sucker ain't never coming off.

Well... it's kind of embarrasing but I'm using a piece of pantyhose over my mas because there is no room for an air filter with the IC pipes and the 2g mas with the hard intake pipe. I've been wanting to make a custom intake that goes down instead of up so I could put on an air filter but I haven't got around to it. Do you think that the mas resistor could actually get dirty enough with only pantyhose to filter the air to cause messed up readings? It never has a problem like this before, and I have been running the mas like that well before I got my exhaust put, for at least 2 months.

The o2 is fluctuating normally on my logger but I'm sure the readings are slightly off because of the exhaust leak, but I ordered the slowboy evo3 dp gasket so it will be fixed when it gets here.

 

[95blackGsTurbo]

Don't see why you can't get a filter in there. probably 90% of tuners run hard intercooler pipe and intake and filer fits fine. Just have to get the right sized one. Take some rubbing alcohol and dip a q-tip in it and clean off the resistor. Running a pantyhose is very bad.

 

[JayRolla]

I know your problem. Your running the xspower long route kit and you cant get the 2gmaf to fit in there with a filter. Im going to have the same problem. Dejon makes a nice intake made for long route kits like this. Here is the part# CIP-1gR www.dejonpowerhouse.com See on the pic that there is way more than enough room for the UICP. Also you are recirculating your BOV right?

 

[90 GSX]

JayRolla you are right on the money. I'm going to try to point the intake down and build a cold air box somewhere near the stock smic. I could make it work if I went to a blow through gm mas, but I'm reluctant to do that because I want to my car as unmodified as possible without sacrificing performance and I don't want to use a translator. My car looks stock, sound fairly quiet, has stock rims, stock height etc, the only giveaway is the front mount which nobody will see since I'll be winning the race... Plus, the 2g mas with my eprom works perfectly with this setup and I've heard that there are no power gains with the gm mas, only a little spool time. If I can't get it to work the way it is, I'll probably get the dejon intake pipe and call it a day.

I converted my supercharged trans am to a blow through setup, and over time I got a light oil film that built up on the mas resistors I'm guessing from the blower seals. Cleaning the mas made a HUGE difference, I'm going to try cleaning the 2g and see if it makes a difference. By the way, CRC makes a specific mas cleaner that you spray on and leave. It evaporates very quickly and leaves the mas sparkling. You can get it at kragen.

I am still reluctant to blame the problem on a dirty mas, although it's quite possible. Does anybody else have suggestions or comments?

 

[JayRolla]

I wouldnt go to a GM maf either. Its way easier to tune the 2g maf. You are recirculating your BOV right?

 

[awdtalontsi1992]

I'm still stuck on the DP exhaust leak. Is the leak before or after the O2 sensor. If it is before the sensor than the leak could be causing your O2 sensor to read a slight false lean. The computer would compensate by richening your fuel trims. Overtime the long term trim could have screwed up the mixture. If it was only a slight leak that is why it could have taken a week.

 

[GVR4592]

Clogged catalytic converter

 

[tearintalon1]

Boost leaks, exhaust leaks, The o2 sensor could be bad. Sometimes when you move and replace it during a exhaust and manifold upgrade if the sensor is old it kicks the bucket.
But any leaks should still be repaired

 

[90 GSX]

The BOV is recirculated. It's a stock 1g so I'm only running 17 psi right now.

The leak is right after the o2 sensor. It's where the o2 housing connects to the downpipe.

It's not a clogged cat, trust me on that one I'm 100% sure.

The o2 sensor is the thin one that came directly from a mitsubishi dealership. It is almost new so I doubt that's the problem. I take care of them when I remove them anyway. But the problem I have occurs at any throttle, meaning that even at 100% when the o2 sensor is not being used for fuel calculations it runs bad. That's why I thought it had something to do with the mas...

 

[MyBeatGSX]

This one was solved in the first post.

I think my plug well gaskets are leaking because there was some oil on the plug boot that comes back even after I clean it. Could that be causing the sluggishness? What else could cause a gradual deterioration in power?

Yes.

Yes.

Problem solved.

 

[JayRolla]

So I see you have a burned ECU and running 17psi. Do you have a logger to see if you knocking and timing is being pulled. Maybe a little lean.

 

[90 GSX]

The car runs perfectly actually. At 17 psi my IDC is around 70%. I am running 19* of timing at 7000 rpm, with an addition 2.5* taken out with the cas and I get zero knock all the way across the board, 24 7 365 no knock. My stock boost gauge is converted to a knock sensor too so I know that it's zero all the time even when I don't have my datalogger out. The car runs, or shall I say ran, damn well. The programmed a/f ratio was bumped up to 10.5:1, still on the rich side but a little leaner than stock. I get 0.85-0.89 o2 voltage on the logger if those numbers can even be trusted...

I see the oil on the plug wells and it accumulates on the wire but the wires looked fine. They are not crusty or corroded or anything. Is that still a problem? They didn't always leak, i know that much. Is it also common for all four gaskets to leak? Because all four of mine are.

I probably should get new wires right...

Actually, it might be the oil filler cap... hmmm can you replace the gasket on the cap or do you need to get a new cap? I kind of like mine.

I think I'll just replace everything, and the pcv just to be sure...

 

[90 GSX]

Fixed the plug well seals, replaced wires, problem is still there. I'm going to take some logger runs right now and see if I missed something before... damn car why can't it just run right.

 

[oldman]

Compression? Jumped timing?

 

[GVR4592]

It's not a clogged cat, trust me on that one I'm 100% sure.

Do you have a catalytic converter?

 

[90 GSX]

Compression is 185 across the board. The motor is strong, and if I skipped timing, which it didn't because I did the timing belt perfectly and its been that way for about 20k miles, the compression wouldn't be where it is.

I didn't want to say it flat out, cats are not something I like to discuss openly.

As I drove it tonight, it had limited power but no knock. I was seeing like 10-14* degrees of timing with no counts of knock... what the hell is up with that? That's the only wacky thing I noticed on my logger other than my low fuel trim but it's always been out of wack, probably because I don't have an aircan on the car.

Also, the car is doing some strange things, almost like a plug wire or ignition problem of some kind causing a weak spark. Randomly as I accelerate the car will stumble for a few seconds. I'll try to personify the sounds, it goes something like this... vvvvvvvvvvvbrrrrrvvvvvvvbrrrrr. vvvvv is the normal exhaust hum, the brrrrr is when the car is missing for a 2 or 3 seconds really bad. Is it possible that it's the power transistor for the ignition? I already tried the coil pack.

 

[90 GSX]

I just ruled out the PT...

If I am under heavy boost and let off the throttle the car pops or backfires. What gives here???

 

[90 GSX]

I edited the original post... anybody know what could cause a weak spark on all 4 cylinders.

 

[90 GSX]

It was the cas for anybody who is interested. PROBLEM SOLVED.