Ok i own a 97' honda prelude, and i have ran into a couple little problems, well i hope their little. So ill just be driving down the road and then all of the sudden the car like jolts, the speedometer hits 0 and tach hits 0 rpm for a split second and then is right back to normal. It has happened 3 times, i'm not sure what it is. Also there is a little misfire i have detected. So to combat the misfire i thought it may have been old wires, cap and rotor, etc. I replaced the cap and rotor with a msd cap and rotor kit, and the wires with 8.5mm super conductor msd wires. And it didn't fix the issue, what should i check next? What about the grounds for the car? If someone could provide me with information where all the grounds were located i will check those and make sure something didn't come lose.
Thanks in advance,
Ian

 

Also its not constantly misfiring, it just misfires about 10 times and then it idles fine again, for a couple minutes or so then starts misfiring again. I've been running 93 octane v-power from shell im going to start running 91 since i read up on how 93 can effect your gas milage, i don't think it has anything to do with it misfiring though.

 

a misfire WILL affect mileage, in a bad way. you mentioned that you changed some things...dumb question, did you change the PLUGS?????

 

i changed the plugs when i got the car, they are ngk plugs, and may have like 10k miles on them.

 

bump please

 

If the tach and the speedo both go to 0 and you have having a misfire problem I would check the ecu. I would also check the grounds both for the car and the ecu.

Does the problem with the tach and speedo happen at the same time you feel the misfire?

 

no only time it ever misfires is when it is idling, that's the only time i notice, but i have been running 93 octane v-power, and i just read that these car's need 91 only so i just ran out of 93 and put 91 in it, maybe that may help with the misfire, im not sure, just a thought. For the tach and speedometer going crazy i'm not sure. It hasn't happened in a while, where are the ground locations?

 

anyone?

 

93 gas will not cause a misfire. Did you check the main grounds on the car? As for the ecu ground I have no idea where it would be in your car I only have 3rd gen preludes.

 

Next is the ignition module & coil

 

anyone have a ground diagram?

 

Checked for vaccuum leaks?