[cobraGT40]

I have the FFR 2282, everything is stock from the 91 Mustang. The problem is that when I acelerate at normal RPM's, and I want to shift to second or third gear, the engine stay at relative high RPM's. I check the acelerator cable for binds, but it return to the original position immediately.
I check it at idle and it is the same problem.
The engine response very good, but when remove the aceleration, the engine go back to the normal RPM's, but it take about 2 to 3 seconds to go back to normal.
Any help will be apreciated.

Bernardo Aillon

 

[Constant Craving]

Sounds like it could be a bad Vehicle Speed Sensor (VSS) or the Throttle Position Sensor (TPS) is bad or needs adjusted.

 

[Inman Lanier]

2-3 seconds is normal for the return to idle. I assume you are asking this question because you are used to carb motors that snap right back to idle speed when you lift off.
The reason for this is emissions - when you lift off the throttle, if the air flow instantly cuts off, like in a carb, you get a large burst of hydrocarbons (short amount of time of very rich). This belch of HC ruins the emissions quals, so they intentionally program a gradual deceleration so that the air matches the fuel and it will all burn (hence low HC).
Get used to it!

 

[paul burchett]

It's normal.

 

[cobra9268]

if you ever step up with serious performance add ons it will stop...The reason i say this is when its all together no matter how many parts you put together you need to get it all dailed in a past 500 hp it is sooooooo necessary..

 

[Dior55]

TPS. I had a bad one on my commuter stang. It gave an accurate .92 volt reading at idle. But she would go haywire when driving. (My RPMs would go UP when I went to shift -- I'd sound like a new kid just learning how to drive a clutch!) New TPS worked out nicely.

 

[cobraGT40]

Thank you very much to all for the information, I will check the TPS.

Bernardo