Problem with Tach...needle reads 3000Rpm and doing 80 in a 4th gen SI.

It was very cold out and the car had been sitting all day...
all the gear ranges have shifted some because of the cold weather but that should not account for the needle ping ponging around.

80mph @ 3 grand then let off the throtle went to 4000
when the gas was reapplied it dropped back to 3000

it would be nice if preludes were acctually able to produce 80 at 3000 but this is not the case

help if posible

 

not sure why it would do that but it definitely should be at 4 g's at 80 mph in 5th gear. Is it still doing that when the car is warmed up? Also is it just the tach that is messed up or does something fell wrong with the motor?

 

I just noticed that when i started the car it was idleing at 1500

im kinda stumped???

 

The motor feels fine not jumpy and it sounds normal



Modified by DJ Rub-ISH at 9:17 AM 12/14/2003

 

It sounds like your clutch is gone.

Your car will slip the most when in 5th gear, so it sounds like your clutch just went out on ya.

 

but usually when the clutch slips the rpms fly up when you give it gas not go down.<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LudeyKrus &raquo;</TD></TR><TR><TD CLASS="quote">It sounds like your clutch is gone.

Your car will slip the most when in 5th gear, so it sounds like your clutch just went out on ya.</TD></TR></TABLE>

 

bad cluster

 

i know for a fact that the clutch isnt slipping...do you think that the tach could just be going hay wire.

I was in an accident the weekend before thanksgiving the right fender was really fucked up but i don't think that had any effect on the engine bay

 

might have knocked a wire lose?

 

I would guess it's the Ignitor inside the Distributor going. Very common problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sephro &raquo;</TD></TR><TR><TD CLASS="quote">I would guess it's the Ignitor inside the Distributor going. Very common problem. </TD></TR></TABLE>

that gets my vote

 

you can test the wire out.

Find the blue tach test wire, and tap into it. Run the wire into your car, and get a digital multi-meter. (well I guess an analog one would work also).

Put the meter on AC and connect the red to your extended tach wire, and black to ground. Start it up and watch the voltage on the meter. At idle the car should read somewhere around 6-6.5 volts (around 1000-1500 rpms). Rev the car and see how the voltage adjusts to the slow increase in RPM's. Now find the voltage
with the car at 4000 RPM's, and maybe 3500 and 3000. Remember them. Now take the car for a drive and do the same things you did above (in your post). If the voltage on the tach drops when you give it gas at 80 mphs then the circuitry making up the tach signal is bad. If the voltage reads about the same as when you just revved the car to 4000 RPM's, then something with the cluster is more than likely to be the cause.

What you can do at that point is tag into the tach wire behind the insturment cluster and do the same thing, which will let you know if there's a brake or short in the tach wire to the dash. If it reads fine also, then the cluster is definantly at fault.

 

thanks man im gonna try that i also just realized that right before my accident i had installed some Jdm headlights and the syncronization of the headlights i.e. the normal head lights to the highbeams is messed up. this could acount for some of the bad wiring or incorrect wiring.

I have a two way bulb in the headlight slot and the h1 bulbs are always one whichi is a problem because they are wirred like parking lights....

 

Is there any damage i can do to the car bydriving it or should i keep it off the road till the problem is solve

 

if it is going then the car could stall...
I wouldn't be too concered if your basicly stock. But I would fix it ASAP.

 

if it doesn't feel like the engine is cutting out, you'll be fine. Just be careful of revving it way up, the needle might not keep up and you might bounce off of the revv limiter. Other than that, you *should* be fine

 

Cool thanks guys

im gonna get it checked out tomorrow