Jump to content

after 3" maf w/ tranlator I run oober lean!


tpoof100
 Share

Recommended Posts

Well I have completed a build this summer and am wrapping things up. I am adding the GM 3" maf w/ tranlator now and my car is running off the chart on my aem wide band (higher than 17). I tuned the translator as instructed by the manual and ended up with this...

 

The car idles very rough (pulses up and down about 600 rpm variation) until the rpm get up to 2,000. Set the translater to fully rich witch is about 8 clicks clockwise and the a/f came down to 14.5 only. I tried driving it like this to see if that is why it wasnt working right and it would go until boost was 0 and would stumble down to idle rpm.

 

The car runs at 13.5 a/f with the stock mas and runs great. No, stumbling occured up to 5 psi (rebuild got to keep it easy for the break in) and idled a little rough at 800 rpm.

 

The last time I had started it the car shut off right away and the ISC just spun as the car was off???? I turned the car on and off again and the ISC still spun. I un plugged the battery and it stopped. The TB was making a spinning noise and the ISC was hot so that is giving me the impression that is shot. It wont start anymore now. I plan to replace that now, but would that cause my lean problem?

 

I have triple checked the wiring of the new maf and translator. lights in the translator blink correctly to show its working. fuel pressure is set at 38psi. plug wires, plugs, and coil are all under 1,000 miles on them, done spring 08. I put on a aem dry flow filter on the new t3/t4 turbo. could the motor be sucking in more air than it should have? Could it be too big or flow too well?

 

What could be causing me to run so lean? Hope you have some ideas.

 

This is whats been done in the last 2 years and what I have to consider in this problem.

89 Blk Conquest, .040 8:1 JE pistons, non jet head, 3'' Alumi. Griffin radiator, 274 cam, 2.5'' straight exhaust, T3/T4 Garret turbo, T.T. Injectors 650cc prim. & 950cc sec., Walbro Fuel Pump, Mookeeh adj. FPR, Larger intercooler w/ 2.5'' hard pipes and a HKS type H BOV, 3†GM Maf w/ translator, AEM wideband O2, 3 wire O2 for the ECU, Rear battery relocation, GM 110 alternator and removed: coal canister, EGR, balance shaft. I added autometer boost, exhaust temp, oil pressure, and water temp gauges.

Link to comment
Share on other sites

could the stock mas be telling the ISC info that the translator isn't?

 

The intercooler and intake piping couplers were all double checked as well. Vacuum lines are tight too.

 

The turbo is on a turbonetics log type exhaust manifold with a tial 38mm wastgate and a pyrometer between #3and #4 cylinders.

Link to comment
Share on other sites

Well, it definately isn't flowing too much, if it did, my car wouldn't run at all, I have a bigger exhaust and compressor housing and MPI, so that's not the problem.

 

Also Dad, I think the translator isn't even really working. It should work almost perfectly just plugging it in and leaving the settings all stock (at zero). It's worked for me just doing that.

 

Could you maybe have a bad maf translator? Or, maybe you can try plugging it without that extension wire, see if that causes any change. Because with any of those knobs full rich, it should not want to run because it's too rich.

Link to comment
Share on other sites

LazarusTsi, its easy to set up, just match the plugs up stock red wire to the translator pink wire. You will have to trim off part of the plastic on the translator side to make it fit and you are done. there is more detailed instructions if you search in the engine mod area. the white and purple wires on the translator are not used. Otherwise follow the instructions on the translator. its explained very well.

 

Dad, the richest I had it set to was the base knob set at about 6 clicks and the idle at 8 clicks (max rich) it brought the a/f down to around 14.5-15 and the idle kinda smoothed out. I drove once around the block and the car wouldnt accelerate with any boost. the boost gauge would level out to 0 and the car would just loose all power to accelerate only got to about 10-15 mph. And to give you a base to work off of the stock mas doesnt cause this problem and it runs normal. (a/f is good and I could run normal into a little boost)

Link to comment
Share on other sites

There's got to be something wrong with that specific translator or the mass air sensor itself. I can see if a buddy will let me borrow his that he's not using.

 

 

Yea, i'd try a known good unit.

 

( I'm sure you know that you make adjustments with the car and ignition OFF)

 

Dad

Edited by Dad
Link to comment
Share on other sites

The Base switch on the MAT is reverse of what you think. Do not have the directions in front of me but to richen the entire fuel curve you adjust the base for smaller injectors.

 

Hope this helps.

 

RG

Edited by RGAV8R
Link to comment
Share on other sites

 Share

×
×
  • Create New...