Ok an update after taking in some suggestions I have seen on the forums.

I went and checked all my motor grounds and even tightened them up. Tach is still jumping around at times, . I also notice a decrease in power if the tach starts jumping while im in the gas.

Any other ideas or other non-motor grounds that i can check? VAFC says all is well, no RPM jumping.

Also never seems to jump while at idle seems to jump when i am putting a load in the motor higher RPMS accelerating or highways speeds.


Modified by flatline911 at 5:06 PM 4/23/2007

 

Bad wiring..?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam_J &raquo;</TD></TR><TR><TD CLASS="quote">Bad wiring..?</TD></TR></TABLE>

Thanks!

I never had this problem until recently I have had the swap for over a year. Anyone else have any ideas. VAGC looks great I dont understand why i would be losing power when the tach jumps if the VAFC is showing great.

Stuck. Any help would be appreciated.

 

Has the wiring for the tach become degraded or near something else like your relay box under the hood? Anything that can put out electronic interference could mess with the signal being sent to the tac. I had the same problem with my Ignition until I installed an MSD box and mounted it under my seat. Problem went away after that. Wierd stuff.

 

i have this same problem on my 1989 accord lxi. Im getting lose of power, making it hard to go 45mph and the tachometer is jumping up and down a 1000x or so. But the car idles fine and if it's in park i can rev the engine and everything works just fine, no jumping tachometer and climbs through the RPM's smooth. If you figure it out could you post the fix, and ill do the same.

 

if there are no problems with your wiring, battery power, or grounds. I suggest an ignition upgrade such as wires, sparks, ground kit, and or as said in post above an ignition module. Reason being you may not have enough watts going through the wire at certain points in order to keep consitency in the tach its 746Watts per hp so check into that. Goodluck!

 

I konw the speed sensor can make the tach jump, dont know about the power loss

 

I have same trouble with my B16 engine, tachometer is jumping & power loss, but only when hot, all groundes are ok, i have replaced for test distributor & main relay, but nothing changed

 

Just curious, are you running OBDI or II?

 

I am still battleing this problem. Going to order a coil today

 

Ok so today on the way home from work i was limping. Car stalled twice at two different stop lights but would idle fine at other ones all the while tach jumping around like a fish out of water.

Also i have an air flow meter in my car and i noticed its always pegged rich now as before when i would idle it would bouce between lean and rich. Also stays pegged to rich while driving.

Doesnt the VAFC get the signal for its RPMS from the same place as my tach? THe VAFC reads everything is great. Could it be ECU going bad?

 

If the car was running fine and started doing this then the ignitor is going bad.
Don't get an aftermarket ignitor, go to the dealer and buy a replacement ignitor (inside the distributor)
I have been through that on two hondas so far.

 

no CEL? I would say ignitor or VSS

 

Ordered a JDM distributor today ill update after install.

 

OK, got the JDM distributor and thing is still messed up Same symptoms tach jumping and if i let it idle it will kill itself like engine miss fired. Also this gradually came on it didnt happen overnight. Slowly evolved into being this bad in about 3 months time.

Motor and ecu is OBD1 Chipped P28. Motor is running very rich when it is runnning. Also VAFC RPMs dont budge and show everything is great.

Could my ECU be going bad? Speed sensor do this?

Please help car has been down two weeks and im out of ideas.

Thanks

 

Any Ideas or suggestions? Can i put the old stock ECU in if I unhook the obd2=obd1 harness?

 

Problem Resolved!

I tore the engine apart and found a loose ground on the side of the intake manifold. I had no idea there was a ground there it is very hard to see.

 

I was about to suggest checking the grounds. Glad you found the problem