| Author | Message | ||
     Stuckinoregon |
http://www.flickr.com/photos/47055595@N07/48291966 99/ Here is a picture of my ECMSpy screen with my bike with the key on but not running. It's after a proper reset - everything warmed up etc. This is the throttle percentage, degree open and the voltage that the TPS/ECU generates with the bike idling at about 1000 to 1100 RPM. It has always read this way, as long as I have had ECMSpy - about 2 years now. I have constantly struggled with idle quality and low speed performance - changing everything from intake seals to the engine temp sensor. If you take a look at the fuel map - it starts well below that throttle percentage on the grid (it starts at 4%)and goes up from there. Could it be that my idle performance is so bad because the TPS is giving a voltage below the fuel map's ability to compensate? And could I change the TPS out and get a higher voltage at the same throttle opening? I have heard that the TPS is the same as an 1989 5.0 mustang - is that the case? Thanks for the help, Sam | ||
| Towpro |
Sam, what am I missing in this picture. Why don't any of the gauges show any numbers? AFV of 0, Temp of 0. I would guess that the TPS is also low across the complete range, which means your using the wrong fueling maps across the whole range. Of course your AFV is going to try to adjust it, but the real answer is to get the TPS up where it belongs. Garbage in (bad reading) Garbage out (runs bad). Can't help with the crossover to Ford parts. | ||
| Stuckinoregon |
OK sweet - but how do I get the TPS voltage up? Do I just replace the TPS or does the whole ECM need to be replaced? My AFV has been running about 102-107 BTW Thanks for the help | ||
| Towpro |
The TPS is a variable resister, or potentiometer, this is a schematic diagram of what they look like.  Picture the LS is connected to a fixed voltage output from the ECM (either 12 or 5v dc). the RS is hooked to ground. The arrow is the output of the TPS, which goes to the input to the ECM telling the TPS. As the throttle moves, the arrow moves from one side to the other. Idle is near ground (low voltage output) WOT is near positive (high voltage output). as the arrow moves from idle to WOT, the output voltage goes up. Once you tell the ECM where 0 is, it should be able to track the TPS by the output voltage. But your TPS output seems to be lower then the ECM thinks it should be. I hate to spend somebody else s money. Does the service manual have a diagnostic measurement (in Ohms) across the TPS (from ground to positive side)? that would be a place to start. I don't have a service manual, is there any adjustment to the TPS mounts? Is there any resistance between the output wire of the TPS to the connector on the ECM? | ||
| Towpro |
Just thinking out loud: if it was a ground problem, I would expect to see a higher then expected voltage because resistance in a ground wire will extend the potentiometer to the place of resistance in the ground. And if you have a ground problem, I would hope the ECM would set a code and CEL because it sees more resistance across the TPS then it expects. How hard is it to change a TPS? Got a buddy who will let you try his (or hers)? | ||
| Stuckinoregon |
Its not hard at all - just expensive. They want 78 bux to order one at the dealer. After reading the service manual, I am within spec at .65v for closed throttle. It is on the lower end of the scale at .5v to 1.5v but the manual says it's ok the way it is. It also says to slowly roll the throttle on and see if there are any voltage spikes - and to check that WOT is 5v and no more. I will try that next. The trouble code is number 11 - but I never received a trouble code, just a really awful running motorcycle. Hopefully I will find something out that can help a bit. |
