JasonST

I've been having a problem with my tach bouncing up and down alot, and now my speedo is sometimes bouncing along with it, anywhere it wants, tach goes everywhere and speedo bounces everywhere too. While this is happening car runs ok, not misfiring, but it will cut out at 6500 rpm, I had it datalogged and the cut said that the ecu was reading 0 rpms when it was bouncing. I replaced everything in the dizzy, and all the ignition stuff, still have the problem. Anyone got any ideas? O and no cels eather.

NirVTEC

I had a similar issue last year with my MSD igntion while it was retarding timing. It was just the Tach though. Once I hooked the tach lead direct to the MSD it was fine.
(I was using an MSD Dig6 to retard timing hooked up to a Nitrous solenoid)

JasonST

Thanks for the help, I'm not sure if it helps me though, I got stock ignition. Anyone else have some advice?

Duane_in_Japan

the two are not related, change the entire speedo / tach cluster assy.

accord-lude

Check all your grounds and make sure they're not loose.

SKDRCR

Does the check engine light even flicker when the sppedo/rpms drop?

JasonST

I don't think so, though I don't remember that well cause I was paying attention to the tach and speedo, I'll try looking for more things today. Thanks. And the tach and speedo doesn't really drop, it just bounced everywhere, like from left to right all over till it finally stops and reads correctly after 10 seconds.

JasonST

Actually SKDRCR, I don't know if this helps, but everytime it redlines itself early cause of the tach problem, the check engine light turns off, then turns back on when I resume cruising cause of my EGR, and Vtec won't work in next gear if I stay on it, I was told this is because the ecu wouldn't let Vtec engage cause it though the rpms were at 0 when he was datalogging it, hope this helps describe my problem better.

phateless

one of the techs at my dealer told me the dizzy itself has to be replaced to solve this problem. something about loose contacts somewhere. this is one of the master techs. try swapping with a known good dizzy to see if it helps?

JasonST

Ok thanks, I ordered a new dizzy 3 weeks ago, it's backordered so i'm stuck waiting for it, the guy said it should come tomorrow, Monday though, but not a 100% guarentee. I'll let u know. Thanks.

phateless

no problem. i hope we get somewhere with this. my buddy's lude has a similar problem, just not as bad yet.

JasonST

Ok, so my new dizzy finally came today, I was hoping it would fix the problem, but I took my car for a test drive, and the tachometer still bounces and still cuts out at 6500 rpm and drops out of vtec, and still no cels. Plz somone help!

ricoMugenlude97

I had a similar problem with the speedo. I had to clean the VSS and its been fine ever since.

JasonST

Ok bump, problem is getting much worse. I don't think it's an ignition problem anymore. It's misfireing pretty bad, and the tach bounced whenver it feels like it, I tried to engage vtec with it bouncing, and it sounded like it wanted to die, wasn't the proud, BWAHHHH sound, sounded terrible! And I was going on a bumpy stretch of road, and the tach went to 0, random guage lights blinked on and off, like the e brake light, and the battery light and other ones, and the CEL blinked on and off, till bout 15 seconds later everything worked ok again, I'm so completely out of ideas, the only thing I'm kinda thinking is maybe a bad ground somewhere? Plz help!

soundbomber

your alternator ok?

JasonST

Yeah my alternator seams to be fine, it's still charging the battery to 14.5 volts and have been running it for months like this now, unles the alternator is only charging the battery at like a constant 1%, but cranks fine everytime.

JasonST

Edit: K this morning I just tried starting it, and it worked well for a couple seconds but then I went down the road and back and it had a whole mess of problems. Every time I push the clutch out or take it out of gear while I'm moving, the idle goes to like 2500-3000 rpms, then as soon as I'm stopped, it will come back down to 750. So then I got back to my house and it started to feel that it wanted to die, the idle started surging really fast from 1000 on down then back up again, I quickly got out of the car to look at things, I noticed the exhaust was pulsing, every second or so black smoke was coming out of the exhaust like it was running rich. I feel like the ignitor on the NEW dizzy is going out and I haven't even had it a day. Maybe it's something else? Anyone have any help? Thanks.

civic27

good afternoon Jason,
The vehicle speed sensor is defective. replace it and your problems will be gone. have a wonderful day

JasonST

K a little update with some important info here. Just took a look at all my spark plugs, and they're all EXTRELMELY rich. And one has a bunch of oil on it, but other than that they're all 4 extremely black coated, and plus theres black smoke coming out the exhaust, car's running bad, etc.... My question is, what could make my car ALL of a sudden run really rich? I'm not throwing any cels, and my car was working fine up until yesterday. Anyone with some insight?

Duane_in_Japan

OK, you are going to have to watch the engine coolant temp sensor (ECT or TW), this may be near 5 volts and get lower as the car warms up (I THINK), signal back to the computer and the MAP voltage back to the computer, it should be less than ONE volt at idle.

I believe that your TW sensor has taken a dump and is saying the engine is like 40 degrees below zero at times and making the engine go very rich, a regular volt meter should do the trick (back probing the connector).

Also take off your main computer ground off of the thermostat housing and clean it and put everything back together there, the terminal and bolt and aluminum tstat housing, clean all these with a small wire brush. Do you think that when the check engine light comes on with initial key on, that the bulb is full bright like the other idiot lights.

I am still leaning towards a bad head assy with the speedo and tach though.

Is the oil on the one plug inside the cylinder or out where the plug wire meets the spark plug.

mgags7

While I think the vss is definitely worth looking at, the rpm issue is completely separate...

OP: if it makes you feel any better right now we're having the same problem on jd3jdm's car (250whp h22) and its killing him, today I'm going to try to figure it out, and I will let you know if I succeed. The both of you hit vtec then rev limit at 6500 rpm, then have to go back to idle before it will run right again....

He has a secondary tach in line with the stock one, do you have anything like that?? I'm trying to see possible problems with that setup....either way its coming off until I fix this....

The post about random **** blinking all over the place when you hit bumps makes me think this is a ground problem, did you put the motor in?? Check all the following grounds: Ecu ground like Duane said, on the t-stat housing ; Transmission to battery/chassis ; valve cover to chassis, should either connect the the radiator support or to the driver side engine mount, i know your car is a 'teg and its gonna be slightly different but definitely check all of those, make sure theyre there, and then make sure the wires look ok.....

Duane, or anyone else here, I'm having problems getting a clear idea of this from my schematics, but does the tach wire run straight from the distributor to the ecu or does it go elsewhere first??


Modified by mgags7 at 9:00 AM 8/21/2006

mgags7

****I'm double posting instead of editing to bump this post, we need an answer here urgently, this is getting super annoying********

OP: What ecu setup are you using, is it just a p13 or hondata or what (if an ems what ecu are you using, your p72 or a p28 or what???)

Thanks guys

prelittlelude

let me just start by saying i hate troublehooting stuff when there is a pre existing problem. your plugs are all black and **** because of your egr code. if you throw an egr code the ecu is def not going to be happy.

when your driving the car, and the tach starts to bounce does the car still drive smooth? if it driving smooth then your losing the tack signal somewhere on its way to the gauge. if the car gets real choppy then your losing th tach signal before the ecu.

it sound slike you have so many things going on. from egr , to a power or ground issue, to ignition problems.

first things first is i would put a tachometer rigth at the pin on the ecu where it gets its rpm signal. don't forget that honda computers look up fuel and ignition on a RPM vs load table. if the ecu rpm signal is getting interrupted then of course its going to get jumpy. additionally it does seem that this is the case because after this jumpiness occurs you can hit vtec but the ecu caps you off at 6500. this may be the ecu safe gaurding the motor because it knows the rpm signal feed is incosistent.

i find it odd that both the speedo and rpm gauge jump. when they jump do they go higher than they were or just drop and then come back up?

ill do my best to help you both out.

edit: i know the OP doesn't want to hear this but. if you were able to fix your egr code and replace the plugs , it helps eliminate SO many varaibles.

JasonST

wow thanks for all the posts. Anyways, to answer a few questions. Mgags7 I'm using a stock p13, but i tried a friends chipped p28 and still same problem. Also, the speedo doesn't bounce anymore, it only did like once or twice ever. It's the tach i'm worried about. Also, it's not running rich at all anymore. Somehow the tps was way off, and finally it three a code, it was 1.2V at idle, which is way off. Also, I fixed the oil leaking into the spark plug, it was a bad tube seal, now it's fine. Also, the EGR code only comes on when it's fully warmed up and cruising at less than 3k rpms. After fixing the tps and I also changed out my plugs cause they looked pretty fouled, the car revs past 6500k rpm FINALLY! I don't have a clue what I did, but so far 4 times it's revved past 6500 rpms *but* the tach goes from 7000 rpms straight down to 9000 rpms, even though the engine isn't. So I'm afraid the problem will still come back.
To answer the grounds questions. I've checked em all a million times, the ones I have though are the valve cover---> chassy one. The one that goes onto the throttle body. One that's on the thermostat, and one that's on the starter. I didn't know about a tranny---> battery ground? Do u need this?
O and to answere ur question about the tach, no I just got a stock one, from an LS integra. And the speedo doesn't bounce really, it just did once or twice, I'm more worried about the tach cause it does it everytime. When it bounces it goes straight up, to like 9.5k rpms. I had it datalogged and the guy said when it did that the ecu read 0 rpms so it cut it out early at 6500 rpms. Thanks for the help guys! And I hope this helps.

prelittlelude

yeah i was wondering where he was dataloging from? there are many spots to tap into the tach signal, and the only one at this point that matters is if he dataloged right at the ecu pin with a aftermarket tachometer .. all we care about is what the ecu sees