mjm4jc

Ok I have the S5 intake swap completed with fully functional aux ports and VDI, although I am having problems with the RPM switch. I have a few problems that maybe you guys can help me to figure out. First, the computer is trying to find idle and fluctuates between 800--1000 rpms. After it really warms up the fluctuation in idle increases between 600--1000 and wants to stall. I tried to adjust the timing, but it's hard without a steady idle. If I put the timing where it should be, it runs even worse. If I advance it 5-10 degrees, it runs a little better.

Secondly, the car is running way too rich. I have it leaned out all the way, and it still has blue smoke out the exhaust. When I drive it, the car bucks when I step on the throttle. I has plenty of power, but it's intermittent.

I have a new coolant temp sensor, injectors cleaned and tested, new plugs & air filter, and new gas in the tank. The only thing I haven't changed was the cap and rotor and fuel filter. I also decarbonized the engine. I sprayed around the intakes and vacuum lines and it doesn't appear that I have any leaks. Any help would be greatly appreciated.

Thanks,

Mike

gsl-se addict

iTrader: (3)

Mike,

You might just want to remove/block off the BAC. Did you end up using the S5 BAC? Anyway, you can remove it and set the idle a little high so that it doesn't stall when there is extra load on the engine (alt, A/C, etc).

What prob are you having with the RPM switch?

mjm4jc

Hey Kent,

No, I'm using the S3 BAC, since it was an exact fit. I guess I can swap them out and see if anything changes. For the RMP switch-----well it just doesn't come on when it is supposed to. I followed the directions, but no luck. I don't think I have the pulse set to the proper setting, but then again, I've tried them all.

Mike

mjm4jc

Kent,

I installed the S5 BAC and there was no difference. I think that if I can figure out why it is running so rich at idle, it will lead to the cause of everything else. I have a new coolant temp sensor, but what are the odds that I got a bad one?

Mike

woodonastick

iTrader: (1)

im not sure if this is the problem, but my friend has idle surge similar to that and he says its because of a bad tp sensor:shrug:...s5's are notorious for bad tp's

cptpain

iTrader: (1)

first off before messing with timing, you'll need to check the resistance of the TPS sensor(s) if they cant be put within spec, you'll need new ones.

you can find them at a junk yard for like $20 or so.

then you can reset the timing to stock and see if that doesnt help your idle issues. if it stops bouncing, but idles high or low, use the set screw on the intake manifold

mjm4jc

Actually I'm using the S4 TPS. Me set-up is: S5 upper, middle, and lower intakes, S4 TB (to keep the manual OMP activation), S3 TPS (because it's plug and play with the S4 TB and because the S4 TPS is not compatible with the S3 computer), pineapple racing inserts, stock S3 ECU, S3 fuel rail and injectors, and all S3 emission components except no air pump, and ACV. Exhaust is full RB. I just had the injectors cleaned and tested, and they came back as a perfect match. I have a new coolant temp sensor, plugs, wires, air filter. The only thing I haven't checked/replaced yet is the fuel filter. I also am running the 2GDFIS.

There has to be a correlation between a rough, extremely rich idle, and bucking throughout the RPM range with occasional backfiring.

Mike