Mad Tachometer
New User
Joined: Sep 2001
Posts: 1
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Mad Tachometer
I own a 89 Ranger Supercab...2.9efi..86k miles...Problem is the Tach has started to start and stay high w/o the engine acting or sounding different. On cold mornings it reads normal but after the day gets hot it reads high (3000-5000)and its very sensitive to throttle in that it will rise in reported rpm with minimal throtle. A Tranny shop said it has plenty of power and look at exhaust ie. Cat. converter(s). I did that, next was throttle body cleaning..next was check codes..did those...w/o a tack you would not know the diff..what gives??? Seems like some sensor related to heat or expansion.(layman guess, sorry).
Senior User
Joined: Jan 2001
Posts: 416
Likes: 0
Mad Tachometer
I had a 2.3 fourbanger with a tach that did the same thing as yours. It first started when it got real cold out (-20F) but was good otherwise. It would read 6,000 rpm even at idle but after the truck warmed up inside it was ok. Months later it starteed acting up reading all kinds of weird rpms when driving at a constant speed, like 0 rpm then 5,500 then 1,000 then 3,500 etc. It was all over the place. I asked the local Ford dealer what gives and he said I needed a new tach but then it quit doing it for a while so I never replaced it even though it was doing it again when sold the truck. They quoted me a price of $140.00cdn for a new tach.
