New Tach Cluster Reading Low Rpms

Hi, Just joined forum and need a little help! I have a 2004 Base Tacoma 2.4 cyl 5 speed 101,000 miles. Did not have a tach cluster, so I bought one off e-bay. Had it programed with my mileage. It was from an SR5 and part number is 83800-04480 (9500-670A). Supposed to be for 4 cyl 5 speed and plug and play. It went in fine and speedometer worked great, but the tach is about 1/3 slow. At 60 mph it reads about 1500 rpms. Idles at 500 or below. It also does not show my ABS light or SRS Airbag light upon start up (which my base cluster did). Do you think the cluster is bad or just something wrong with the hookup? Maybe from an automatic, if that matters. It was simply 3 plugs to clip in, so I don't think I screwed up during installation. I had previously unhooked the key/door chime connection under the dash, and I don't know if that effects tach or lights. Did I get the right cluster or is it bad or not grounded? I'm going to send it back if the tach is wrong. Everything else (alt, oil, gas gauge, temp) appears to work. New bulbs, so should not be that problem. Guess I'll go back to my base cluster If I can't resolve the problem. Any expertise in this matter would be greatly appreciated.
Hope this in in the right place in the forum and sorry for the length of post! Thanks!!!

Terry

 

Sounds like it was from a 6 cylinder and it expects more ignition signals per revolution. It would read 2000RPM when it should say 3000.

Do a search. I remember reading about someone adjusting something to make a 6 cylinder tach work on a 4 cylinder.


...this may have been the post. There may be others that have done this. It involves swapping a small circuit board from your old cluster, although you may not have that board on a non-tach cluster.

https://www.tacomaworld.com/threads...-with-a-tachometer.262145/page-2#post-7792900

 

How did you fixed it @Cotton Hauler ?
My tach shows from idle to 2500max. Is there a module from V4 on my V6 tach?

 

V4 doesn’t exist. You’re thinking of I4.

Nothing you can really do if you’re trying to swap clusters. You just have to have the correct once with the correct displacement.

 

yeah no V4 lol I meant 4 cylinder

I don't really want to go in. I was reading on other posts that sometimes it does that when someone swap it from 4cyl to V6. I noticed today that it does that mainly on 4th gear I even saw 3000RPMs going 70 on 5th

Strange

 

Where did you get your tach?

Is the reading consistent, like always 3/4 or 2/3 of the actual RPM? You can get the actual RPM from the live data using a scanner on the OBD2 port.

 

Thanks DrZ. I just got this car, I wasn't doing anything to tach.

Yes it is consistent, it slowly goes up to 3000RPMs most. Mostly to about 2300RPMs thought! On 4th gear going 60mph reading is 2300RPMs (???). On 5th I measured 3000 at 70MPH. I wasn't trying to go faster to see if I get more RPMs.

I was told at my mechanic that someone was doing something with transmission (red sealer), wonder if that is problem there...or just loose somewhere...

it is not that big deal but bit annoying

 

Are you saying at the same speed the RPMs are lower in 4th gear than they are in 5th gear?

What are your RPMs at 60 MPH in 4th and 5th gear?

You really should hook up an OBD scanner and look at the live data to see what the computer thinks the RPM snd MPH are and compare that to the gauges.

Do you have standard size tires? If not that can make the speedometer be off.

And the tachometer doesn't get it's input from the transmission. It's all from the ignition system as far as I know, so shifting gears shouldn't throw it off other than the normal change in RPM that you'd expect from a different gear ratio.

 

Thanks DrZ!

I have stock tires. I don't have OBD scanner. Is it that regular computer scanner that I can get reading from at auto stores?

I have to try RPMs on 4th and 5th tomorrow. Don't drive it much

Thanks for trying and helping!

 

I would get a scan tool so you can get the live data reset the needle on your tachometer to what the live data is saying then go from there. That is what I did on my 97 that i upgraded. it was spot on in all 5 gears and at any speed after that.

 

You can get a bluetooth OBD reader that connects to a smart phone for $20 or less. Do a search in this forum or other places to learn more about them. It's also handy to carry in the truck in case the CEL comes on and you want to see what the problem is. The live data will show you the rpm, mph, air and coolant temperatures, throttle angle, fuel injector trim, etc.

 

The cluster in its entirety does not matter, what matters is the odometer. You have to have to correct odometer for the engine installed in your truck. The odometer can either be from an automatic or a manual which allows you to get the odometer from a black gauge face cluster and use it in a white faced cluster.

 

No. 4th gear 60MPH I measured today 2750RPM, on 5th 60MPH 2250RPMs
Seems like RPMs on tach showing little more. COuld it be because of spark plugs I changed few weeks ago? That computer is adjusting? Because I've measured about 2300RPMs on 4th when I started writing here

 

That is cool idea DrZ!! Thanks for tip .)

 

My Tachometer on my 99 Tacoma V6 5 speed reads high and the difference gets greater with higher RPMs. One thing i do know is it was originally manufactured as an American truck sold in the USA and has such been imported into Canada and is now in KM's. Is it possible that the wrong tachometer has been put in ? I know it is off because my live engine data says so. Any help would be appreciated thanks

 

Sounds like it's the wrong tach. A tach from a 4-cylinder in a 6-cylnder would read 1.5x higher that it should. So when your live engine data shows 2000 rpm the tach would show 3000. At 3000 the tach would show 4500, etc. Is that what you see?

 

Yes basically what i see thank you.If i get a new tach from a junk yard how would i go about correcting the odometer ?

 

You can swap the old speedometer/odometer to the new cluster, but you may have to change the faceplate then reinstall the needle and calibrate it while driving. Maybe someone else can verify this? It may be hard to find a cluster that matches the year and options, as there were a lot of variations over the 1st gen 96-04.

Or try to find and swap the little circuit board that the tach uses that determines if it's 4 or 6 cylinders.

 

What year cluster will work with my truck i have acces to a 2001 Tacoma V6 4x4 5 speed same as mine but newer ?

 

I'm not sure, but if you could get a tach cluster from a 6 cylinder you may be able to just swap over the little curcuit board that was discussed in the link I posted earlier here.