nitenshinarmor

Engine sounding normal like always. I had taken the 2000 WS6 to CC about 3 wks ago. I felt I should have went faster than 12.6 in the 1/4 with the new nitto 555r's. After 3 tries, I went home after my best time was a 12.75. The car hooked up like a ****. Unlike the kuhmos I had. The kuhmos, I had to baby the throttle to get the 12.6. If I didn't, I would spin through 2nd into 3rd. Now with the Nittos, I just stomped on the gas and they hooked w/o spinning. I got a 12.75....WTF??? So, I haven't really done anything except change out the plug wires. Still no change and having really big loss in hp. So, today, I took the WS6 to SRracing to see what is going on with the dyno. I loss approximately 70hp. The car isn't missing. The A/F was running around 16 to 17. Way to lean. After discussing this for approximately 15 to 20 minutes, we decide to play with the fuel enrichment tables. I gained most of my hp back within 12 hp and running around 13.8 A/F ratio. I thought we was onto something until the last 2 pulls. The car went back to running lean and 70 hp loss. It didn't really matter what we did, it did almost the same as it did on the first pull. The only difference was the car had a slight bit better A/F ratio. I just don't think it could be mechanically related. If it were, I don't think we would have been able to tune it out and go havic like it did. It seems as it maybe something electrical. I called a friend of mine, and he felt that it could be the fuel beginning to start vaporizing because of the fuel lines not having the heat shield tape on the fuel lines like it came from the factory. But not for sure. So, my question would be, does anyone here have any suggestions or ideals what I may need to look at to resolve my problem/s?

Thanks,
Doug

nitenshinarmor

Anybody? I really need to find this problem before it turns into something really big.

JMBLOWNWS6

iTrader: (17)

1.Check your fuel pressure.
2. What are your O2's reading?

nitenshinarmor

Fuel pressure reading was 60 psi. I had asked about the O2's while I was at the dyno shop and he did not feel like the O2's was the problem. He had stated if you lost that kind of hp and it being your O2's, you would have probally got a SES light to come on. The whole time, the SES light never came on.

JMBLOWNWS6

iTrader: (17)

Wow maybe your MAF is on its way out. Hell man thats a tuff one.

nitenshinarmor

Hopefully, someone has encounter this problem before and can help me. I am glad I kept all of my stock stuff for a just in-case need. However, I have never tuned w/o a wideband O2 at a dyno shop. I wouldn't even know how to with just my HPTuner. Therefore, me trying my stock MAF won't do me much good to troubleshoot, I wouldn't think.

JMBLOWNWS6

iTrader: (17)

I would put the stock maf back on if you allready havent tried. JMO

nitenshinarmor

Will try that. However, I won't be able to tell if that fix the problem until I place the car on the dyno or take it to the track.

nitenshinarmor

to the top

nitenshinarmor

Just got done spraying water all around the intake and intake components. Found nothing with the intake system. However, I did find the intake bolts less than hand tight. Don't think this is a problem but could lead to a problem. However, I took an air hose and listen through it and found everyone on the egr block off plates leaking. Probally, the problem. I believe this allowed a ton of air getting into the exhaust system and leading the O2's on the car and the sniffer at SRracing to believe the car to be running lean. However, while the car ran in the garage, the smell of gas and my eyes watering like a s.o.b.....the car is indeed running extremely rich. I ordered block off plates and gaskets to go with them. Will put these on and run the car again to see if my eyes start to water. Also, will torque the intake tomorrow to spec of 86 inch pounds....and we'll see if this fixes the problem. If anyone has anymore suggestions, please, please let me know.

Thanks,
Doug

Chevluvr

hey one of my mates over here is having the same problem...he put a decent set of tyres on and his car started leaning out...it was because of the lake of fuel pressure on launch when all the force is going back wards...I dont know why you are having problems on the dyno though???

nitenshinarmor

After talking with the dyno shop, I don't think I found my true problem. I just pulled the plugs on the driver's side and found all of those plugs to show a very lean condition. I also performed a compression test and found nothing yet on the driver's side. Tommorrow, I will be doing the passenger side and posting my findings.

What's odd to all of this, almost everyone I speak to tells me something different to look at. NO-ONE knows why my car is doing what it is doing. This is very very strange to me. However, it is not getting enough fuel to the combustion chambers as it should. Well, at least on the driver's side head. Will continue my investigation and hopefully I will find the answer to this and it looks like I'll have to find the answer by myself. Wish me luck.

Viper

iTrader: (6)

Good luck man, my car on the dyno lost power after 5K and we are in the middle of finding out why. It's tough to diagnose over the net.

nitenshinarmor

So far, this is what I have found. I know what some of the following means to me. But really need some input here. So, without assuming I found the problem of the car running rich/lean, I took my diagnostics up one more level and checked a few more things and would love some feedback on what would be causing my car to run lean.

What's agravating to this whole thing, is that my car does not have anymore than 1500 miles on it since I got it back from getting heads, cam, intake, and e-water pump upgrade. I just said 1500 miles to be safe, however I really don't think I have 500 miles on it since I got it back. The car just sits in the garage and rarely comes out.

OK, here goes....I had performed compression testing of each of my cylinder head gaskets to see what I got. In addition, I check to see what exhaust runners are running hot at idle. Also, I checked the LS6 intake to see if it was torqued down properly. I have found many interesting numbers and need some input from you guys.

Without assuming everyone will know what I am talking about when speaking cylinder location, I will try to explain. Cylinders 2,4,6, and 8 are on the passenger's side with cylinder 2 being closest to the nose of the car and 8 being next to the firewall. Cylinder's 1,3,5, and 7 are on the driver' side with cylinder 1 being closest to the nose of the car and 7 being next to the firewall.

Compression results of cold engine at 72`F

8 = 210 psi / 7 = 197 psi
6 = 240 psi / 5 = 210 psi
4 = 240 psi / 3 = 190 psi
2 = 212 psi / 1 = 210 psi

As I pulled each spark plug out, I inspected them. I found everyone of the sparkplug electrodes to have a white look to them. To me, these mean the car has indeed been running lean.


Infrared temperature readings of car running at idle.

8 = 420`F / 7 = 260`F
6 = 320`F / 5 = 260`F
4 = 300`F / 3 = 265`F
2 = 231`F / 1 = 285`F

Note: emmistivity and angle of infrared gun can affect actual readings. Cylinder 6 and 8 could not be read at the same angles as the rest. Hence, temperature readings on these 2 cylinders may not be correct but close to actual temp.

In addition to the above testing, I found the LS6 intake to be torque down incorrectly based upon GM specs. GM recommends the intakes for these cars to be torqued to 44 in/lbs on 1rst pass sequence and 89 in/lbs on final pass sequence. I found my intake to be varing in torque specifications. There are 10 bolts that torque this intake down. I found 1 bolt to be torqued down to 20 in/lbs, 1 torqued to 25 in/lbs., 5 to be torqued to 30 in/lbs, 1 to be torqued to 40 in/lbs, and 2 to be torqued to 90 in/lbs. I did not torque any of those bolts down yet to spec until I speak with the company who done my heads, cam, intake, and e-water pump upgrade.

Again, anyone with any suggestions please shoot me a line.

Thanks,
Doug

nitenshinarmor

to the top. Somebody...Anybody???

V6 Bird

iTrader: (15)

It sounds to me like there is possible a vacuum leak somewhere...

nitenshinarmor

I believe you are right. The intake is definitely not torqued down correctly.