chuck8313BTSDS

Need help with tuning the new motor and turbo. went from a 86 n/a motor with a T3 60-1 turbo to a small bridge ported turboII motor with a T70 turbo and had to adjust the fuel lean at 1500rpm's and lower and above 1500rpm went rich. Does this sound right? Idle is around 1250rpm's with vacuum at -8 to -7. When the rpm is going from above 2000rpm back to 1250rpm the motor sound and runs like it has a bad spark plug or stuck apex seal. Now going from 1250rpm to 2000rpm or high the motor sound and feels good. Tried to adjust the fuel in the 1250rpm - 2000rpm range but end up with the same problem. Tried adjusting the timeing both ways with no luck. Checked for a vacuum leak, all ok.
Also the air/fuel is running at .89 volts (4 wire O2) now and the egt gauge is going to 1575F at wide open throttle. With the old set up the air/fuel volts were around .92 and the egt would only go to 1450F. I have tried to go richer on the fuel with out any real changes in both gauges. Does the bridge have something to do with my readings? With the overlap of the rotor timing how much unburned air and fuel is going strait out the exhuast port. Is this the reason I am getting the readings I am getting?
Thanks in advance and I did do a search on this.
If a picture or the ports will help there is a link to some pictures on my profile page. the pictures are on page two, picture 19-20.
chuck

Scalliwag

First things first if you think you have a stuck apex seal check your compression. What would help me is to know more about your fuel and ignition systems. Are you running an aftermarket system?

teachermechanic

iTrader: (4)

Hi, i bridge my secondary also on my 93 this winter and have the same problem when i start. After make adjustement - 32 on idle fuel and put 4 BUR9 plug the idle is good. Check the color of your plug. But not to hope good idle under 1500.
For the vacuum on my motor is at 8 to 10 at 1500 and when i start in the first week ( new Apex ) is at 4 to 5. If your Apex seal is new the problem for idle and vacuum is normal, make more Km for match your Apex seal.
The bridge need a lot of setting if you want to make good car for run everyday.

chuck8313BTSDS

scalliwag
The apex seals and plugs are fine, both are new ( april 30 ). the motor just feels like a bad seal or plug at 1250-2000rpm. Under 1250rpm and above 2000rpm the motor runs fine. Did some more runs on the highway and leaned the fuel in the upper rpm range and the egt came down to 1500f. Motor seems to run better also.
Teachermechanic
You'r right about the vacuum, I put some hard miles on it today and the motor seems more drivable. Leaning it out and putting some miles on it helped. the motor feels stronge at 15psi of boost. by friday it will be at 20psi.
Begining to think everything is OK, I am just being paranoid. First time experimenting with any type of bridge port.
chuck