I'm posting this here because it's getting buried in the General Tech section without much help. Here it is:

Went to the dyno to see how the new computer is doing, but we couldn't get a reading below 3k RPMs. ??? If memory serves me correctly, it did this the last time I was there getting some tuning done. The first few pulls were fine, but then couldn't get a reading below 2200 . . . then 2400 . . . then 2500, etc. But like I said, yesterday we couldn't get a reading below 3k.

I'm think it's my torque converter starting to go. I don't drive the Camaro much anymore because of the Saab, but I still want to use it as my fun car. The TC in there now is like a 1850ish stall.

Is that what it is, or am I looking down the wrong path here?

 

Weird converters can throw off the torque calculations but you should be able to get power numbers, just set the X-axis to vehicle speed and hand calc it back if you need to. Dynos take a ratio of engine speed to tire speed to calculate torque; if that ratio is changing a lot (converter slipping then catching up to speed) the software has trouble locking on to a ratio.

 

Anybody else with any ideas?

 

when you say "didn't get a reading" you mean the graph is all screwy, or the dyno just cut out and didn't print a HP reading? There could be some electronic noise interfering with the RPM pickup, but the dyno operator should be able to tell you instantly if it's a problem on their end or yours.

Since your car runs below 3000 rpm it's a problem on their end, at least to me it is.

 

No other car there seemed to have that same problem I was. He said something like, when he floored it, the tach would spike to 3k rpm's before it moved or something like that.

 

So the inductive pickup that was clamped on a plug wire wasn't picking up the RPM's below 3000 rpm? What plug wires are you running? We have to different clamp setups at the shop I worked at (one big one, one little one, highly technical). One of them was specific for clamping on the plug wires and the other was for coil-on-plug type applications that clamped over the signal wires to a coil. Are you running a stock coil or MSD?

 

Stock coil. I really don't understand what you're talking about though. I really don't this this is an electrical problem. I don't see how it could. Maybe what I'm trying to say is that the guy acted like the converter wasn't locking up until 3k which is why we weren't getting anything lower even though he set the dyno to measure from 2k and up.