Tach jumps at idle!!!?!

[newtuner]

i got a 88 lxi with a bt motor and auto trans my tach keeps jumpin between 1500 - 3500 at idle and when i give it gas it jumps really bad!??! anyone kno what it might be??!?

[A20A1]

how'd your 88 get a BT?
musta been left overs.

poor electrical connection... Distributor.

Somehting could be arching...

[newtuner]

do you kno to find out what it could be?? i took my cap off and the points have white crosion?!?? if thats how u spell it. and theres some oild leakin out of my valve cover on that side could that be it?

[X-Lr8]

check the connections from the Distributor to the Coil there should be a plug with a couple of wires and then one single wire right next to it that goes to the radio condenser (little black square on the coil bracket) they should be snug and free of corrosion.

Also on the top of the distributor near the vacuum advance there will be another plug check that as well.

[AccordEpicenter]

when the engine is running at idle... does it sound like a small rock is kicking around in the distributor cap? If it is the dizzy is bad and thats what i would put money on at this point as the problem

[newtuner]

well thx for all of ur help ill chech the dizzy and get back to you guys.

[bluecar5556]

It is the fast idle valve. If the idle is slowing jumping up and quickly dropping down it is the fast idle valve. It is located on the back of the intake manifold and if you take off the 2 screws holding the little plate on the top (its ok to do this). Remove it while its running and take a screwdriver and push the little diaphram down and it will idle perfectly! I am a genius when it comes to 3rd gen accords. Hope this helps. ps. if you dont want fast idle, simply remove the valve and plug up both holes and it will idle when its cold regardless. All the valve does is allow a vacuum leak to idle the car up when its cold so it can warm up faster and there is 2 heater lines going to it that warm up the bimetal spring inside making the spring heat up and shut the valve when the car is hot. If its idling erratically the bimetal spring is bad and the entire valve should be replaced.

[newtuner]

ok thx ill check that but for now i have changed my spark plug wires and cleaned my spark plugs. and when it drops down in idle it sits at about 1000 1250 and dosen't jump untill i turn on my lights, windsheld wipers, heater, rear defrost, hit my brakes, and use my windows!!?? so0o0 i dunno!

[Strugglebucket]

When you say "when it drops down in idle" do you mean after it warms up? And by jump do you mean surging up and down? It's normal for your idle to go down a little bit and then come back up when you put more of a load on the alternator ( defroster, etc.) That's the eacv adjusting the idle. 1000-1250 is kind of high for your car to be idling at. Sometimes if the idle is set too high it will make the eacv act funky and make the idle surge up and down. Try adjusting the idle screw on the throttle body so it's at 750-800 and see if that helps.

[newtuner]

no i mean it bounces up and down and when it warms up it dosent BOUNCE and i mean bounce untill i use a accessory. but also when i drive it it lags and backfires + the tach jumps bad. Could ignition timeing do it? if my dizzys goin out i should hear what sounds like a prbble in the cap right or could that be it?? i know that the tach gets its reading from the coil so if my tach is goin nutz it would have to be my coil right?? well ill have to check everything!!! but if anyone kan help i would greatly appreciate it!

[Strugglebucket]

it lags and backfires? :ugh:
double-check that your plug wires are hooked up correctly. if you have a timing light check the timing. also hook the light up to each plug wire to see if/how well they are firing. have you checked your ecu for codes?

[newtuner]

just changed the plug wires and im getin a timing light tomorrow and im sure the plug wires are hooked up right. i think, its the right hand side of the motor from the front of the car thats the no.1 spark plug right??!? at least thats what the booklet i have said.

[maka_RTH]

yes, the right hand one is the #1 cyl. facing the engine from the front, it looks like this:
4 - 3 - 2 - 1