hondacrx92

My tachometer jumps about like crazy when im driving, its fine when im stopped though. My distributor is brand new, so i ruled that out. I do get a rattling, metallic noise coming from the alternator area when im driving, its like a raspy noise, but its defo not my exhaust. Also when i start the car from cold, i get a squeeling noise which is intermittent coming from this area, but once the car is run for 5 minutes it disappears, any suggestions would be a great help??

YasRex

If your alternator is messed up enough to cause something like this then a lot of things will be going wrong, not just your tach.

Tach just senses pulses from your ignitor. Your rpms arent actually jumping around all over the place so there obviously isnt anything seriously wrong with the dizzy unit just what is being sent to your guages. Wrong signal via wire or displayed wrong.

I would check the wire going in to your guage cluster. Its a blue wire coming directly from the ignition coil. If your fuel guage and coolant temp guage are messed up too its going to be the ground wire.

And if thats ok test a known working guage cluster. Only things it can possibly be.

Civiclized

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That guy is 100% correct.
My cents is that if you think there may be a problem with your alt. (related or not to the issue at hand), pop the belt off and spinning the pully.
I dunno....

strictlyimport

What motor and what car? The squeaking noise is the alt belt need to be tightened. Is your engine reving when your tach jumps, or is it just the tach.....sounds like there could be a bad ground in your wireing from the dizzy to your tach. Make sure that when you changed the dizzy, you didn't pull any wires loose.

hondacrx92

Its a 1992 crx del sol B16A engine. I will need to have a look at the wires in the distributor, i assume you mean the ones that go into the multi- plug, thanks everyone for there interest anyways, hope i can get this fixed

hondacrx92

the engine ir running absolutely great, it puuls like hell and is very smooth, only problems i have is the annoying rattling type noise from alternator area, and my tach jumping about, the engine revs are not going up and down though, just the needle

strictlyimport

Then I would check the wireing on the plugs. Like one guy said in an earlier post, your ignitor is what sends the signal to the tach. Which dizzy did you get? I had a similar issue on my hatch with a sohc vtec, and it was the ignitor going bad.

hondacrx92

I got the distributor from a company called Distributor King if i remember correctly. Thats what ill do, at the weekend ill check the wires see if they look ok, cheers.