the other day my rpm gauge on my cluster started cutting out and bouncing all over and so did my monster tach.. then 1 min later the car started spuddering and bogging out, then it would stop and take off like rocket.. it keeps doing that so i swapped dizzys, put in a walbro 255, new fuel filter, new plugs and wires, new ignition control module and its still doing it... i have a vafc thats hard wired to the ecu and the rpms work perfect through it so i dont think its my ecu... i took out the monster tach and its still doing it.. should i replace my harness.. it think its electrical because the monster tach is only hooked up through the rpm signal wire by the dizzy and the rpm signal wire at the ecu where the vafc is connected is working good.. dont know what to do.. please help me.. when its not cutting out it runs great and pulls hard in between time

 

Just a low level shot in the dark but maybe change the cap and rotor? Otherwise check voltages to the dizzy and fuel pump. Throwing any codes?

 

no its not throwing any codes im assuming because there is no check engine light and i have swapped dizzy and its still doing it so its not the cap and rotor.. i really need help... its like its only cutting out under a big load but the tach jumps all over regardless and then sometimes its doesnt for just a lil bit and then it goes crazy agian

 

could i have a bad relay and when it gets under to much of a load its shutting down or cutting off and then remaking contact agian and working fine

 

You might want to check the YEL/GRN wire that runs from the igniter unit to the ECU for an intermittent short or open.

 

i was originally thinking tps. but if there's no cel and it only does it under load it sounds like it's probably electrical. yea id have to say i agree with the above response.

 

so do i need to check the yellow/green wire from the harness at the distributor back to the ecu.. cuz ive changed distributor.. also i bypassed the blue signal wire and it still didnt change anything.. the car acts lke the fuel is getting shut off so the car just boggs out and then its like it kicks back on and the car runs great.. does anyone know where the fuel pump relay is at.. i looked under the dash and ill i could find is the starter relay and the turn signal relay

 

Correct. Check for intermittent loss of continuity between both ends and also for a short (continuity to ground from either end).

 

in your opinion if it has a short or anything then it would make my car run like this and would it have anything to do with the tach...

 

As you logically did when you first noticed the tach jumping, I too focused on the igniter unit as a possible source of your problem. Given that you have already replaced igniter unit (correct?) and the igniter unit controls ignition timing by receiving signals from the ECU through the YEL/GRN ECU wire, I thought that a bad signal on the YEL/GRN wire might also cause the tach to jump around. So, yes I think a bad YEL/GRN wire might explain your problem.

 

ok thank you.. yes i replaced the ignition module inside the distributor.. its a flat piece where all the connections are at.. thanks for your input.. does that wire control the mph gauge as well.. is the igniter unit something different than the ignition module inside the distributor

 

Igniter unit and ICM (ignition control module) are basically the same but different from the coil. The igniter unit/ICM also produces the signal for the tach.

The speedometer, on the other hand, gets its signal from the VSS or vehicle speed sensor that sits atop the transmission.

 

i only have 1 red/grn wire on the plugs at the ecu... the wire schematic your gave me show the yel/grn wire splitting into 2 diff red/grn wires... do you have any input on this.. it would be greatly appreciated

 

The igniter wires pin to A21 and A22 of the ECU. I believe that each ECU pin for the igniter is responsible for the ignition timing of two cylinders each.

 

thats the same for a p28.. the wiring print out i have shows the red/grn in #21 but nothing in #22.. and when i check the harness i only have that 1 thats why i said that.. why do you think that is

 

also if you dont mind me asking then where are you getting your wiring diagram from

 

For stock 6th generation Civics (96-00), which have OBDII ECUs, only one ICM wire pins to the ECU. Maybe your ECU is like 6th generation Civic ECUs?

 

i dont think so but im not sure.. but for sure it only has 1 red/grn in pin 21 and there is nothing in pin 22.. thank you for your help.. you obvisiously know alot so im sure your familiar w p28 computers? the swap is using a stock civic ex wiring harness w a p28 computer

 

Your P28 should be pinned like this. Note ICM/igniter terminals at A21 and A22.

What year Civic EX wire harness? So, as you were suggesting, there could be a mismatch between your wire harness and ECU?

 

i know this is a pretty old post. but im having the exact same problem. was wondering if you ever figured it out