MSefi.com read only forum (Jan.15,2018)

When driving I'll get a sudden yank, look at my air/fuel and it will be 11:1 or so. This is under normal cruising speeds. It will happen for a split second than go back to regular air/fuel. It happens at random intervals, sometimes not at all. Might happen once out of a 15min drive, may happen 4 times.

Could this be a sign of a bad injector??

Plato2k5

Could be the accel enrich kicking in. This can happen if the Map or TPS threshold is set to low in the accel tuning data. I find it helpful to run a datalog, and set up one of the graphs to read ARF and accel/enrich. Makes it very easy to spot!

Bill

This is how I have the accel enrichment set up:

MAP vs TPS is set to 100%, so I'm not relying on the MAP sensor, just the TPS.

TPSdot threshold % is at 20%.

So your saying that the threshold could be to low? How much should I increase this???

I'll have to look through my data log and see if I can find it happening. Unfortunately when I data log, its usually for around 15mins. So I have a lot of information to sort through.

thanks for the help!

20% is high enough where it should be greater that normal TPS noise. Unless you have a worn/bad TPS, that is causing erratic voltage signals. This could "trick" MS into thinking that your moving the throttle more than you really are.
Should show up in the data log, if its causing the problem though.

Bill

I know of people that rig up a button to ground out the temp sensor for a second in order to "mark" a specific location on a datalog for viewing later. This could help you find your spike faster. Without a datalog of what's happening, it's hard to identify the problem.

Hmm, I like that idea with the grounding idea.

I tried to Upload my datalog on here but it says the file size is to big???