Thread: TPS and MAF

Hi all, just trying to get my head around how the tps and maf settings relate to each other and the ecu. If the tps setting is high and the maf setting is low how does it affect the running of the engine and vice-versa if the tps is low and the maf is high. How do the individual settings of the tps and maf relate to each other and the computer to give good performance/good economy??? Thanks Bob

Originally Posted by PhilipA

Bob, there are lots of posts on this so I suggest a search.
There are also quite a few thorough descriptions of 14CUX on the net.
I assume you are talking 14CUX?
If you are stuck after a search then I have Pdfs of most of the papers on 14CUX I can send you.

However to be brief, the 14CUX does not care what the TPS value is as long as it is within 2 parameters on idle AFAIR .03 and .49 volts. over .49 and the injection cutoff does not work. Some recommend .33 volts but in my experience and IMHO it doesn't matter.

The MAF should be adjusted with a HC tailpipe meter to whatever HC value you want but the usual value is around 1.2 volts ign on, engine off.

If the MAF is high and the TPS low it will be rich at all throttle settings in a steady state.
If the TPS is High( immaterial as the 14CUX is self learning) and the MAF is low it will be lean at steady state .

As the TPS is predictive there may be some advantage on initial fast opening of the throttle if the TPS is high but I personally have found no difference and I have experimented with low/high and middle (.33volts.)
Regards Philip A

Thanks Phillip, that is exactly the info that I was after. All searches that I have done have not explained things as clear as you did. Bob