Hello, I was wondering if anybody has had this problem and knows how to fix it? I have a 91 ranger 3.0 auto 2wd, at idle the tach is reading about 3000 rpm, engine is not idleing that fast. chilton's does'nt help.hope someone here can.

 

Welcome to FTE!!!

I would start by pulling the codes, the ECU should pick this up. I have the procedure in the tech info thread at the top of this forum, pulling eec-iv codes.

 

Does the tach ever correct itself, for is it always 2500+/- fast? Does it stay at 3 grand all the time, or does it drop when you turn off the truck? If the truck is still running normal, I would suspect the tach for the problem. Could possibly be a resistor going bad, a poor connection, or the tach drive could be failing. Price some local instrument clusters in salvage yards, and if they are cheap and in decent conditon, get one and try it.

 

KenOO, I have pulled codes before but everything checked out ok.
Tiggie, with the key off the tach is at 0 with key on engine off the tach moves to about 200. With engine running it goes to 3000 at idle and only moves up to about 4000 with accelaration. truck is running fine. this started out as an intermediate problem now full time. I have a 92 with a 2.3 auto also could I just switch out instrument clusters straight across and check it that way? Thanks for your alls help.

 

I don't think the 2.3 will read accuratly but it should move through the entire range which your isn't doing, I would give it a try.

 

jrf - i've had the exact same problem with the 91 3.0 auto. when i turn it on, tach reads about 3200 thoughout acceleration until (i assume) it gets to revving higher than that. maybe once every two or three weeks, it would drop back into normal working order for a couple of minutes, then get stuck up again. i don't have a solution for you, as i recently suffered a cracked head and am debating if and how i want to get it running again. if you do get it figured out, post it for me on this thread just in case...thanks

 

btw - all the symptoms are the same, except that my tach continues to work above 4000 rpm

 

update! I switched out tach with one from a 94 4.0 that I have and it works fine now.
CAUTION!!! I first switched out complete gauge cluster, when I turned key on all gauges except tach and speedo went clear off the scale. something must not be interchangeable. just a word of caution for those changing gauge clusters. BTW,the 91 had blue film on back, 94 is pink. I hope I didn't ruin other gauges.

 

Glad to hear it works now and thanks for the tips!!!