Tach Jump/Fuel pump shuts off

[93GrnMnstr]

Having some issues with my 93 Accord EX Manual F22A- no mods/original engine and trans. 303,000 miles

Clutch was replaced Monday (yesterday).
Oil change yesterday.
Main relay replaced today.

While driving, occasionally the tach will start to jump around. If I tap the gas pedal and make the engine jump, the needle goes back to current RPMs, and usually it will start again seconds later.

Now, the bigger issue is that occasionally the tach will jump around too much, and especially if the cruise control is on, it will cause the CC to go off, and occasionally the engine will just die.

Last night, the car completely shut off on the highway. I pulled over, started it up once, then it cut off again. Everything works, lights, radio, etc. The engine will just turn with no fuel being delivered. If I kick the dash (under the steering wheel) enough it will start back- thus, I replaced the main relay (again)- still the same thing happening. I drove 3 hours, mostly highway, but when I had to stop for gas, it wouldn't start again. Kicked the dash for a few minutes, started up and ran fine until I got home.

Also, there's a wiring harness that's in between the intake and the PGM-FI (coil harness I think). If I wiggle it- sometimes you can hear the fuel pump click on or off and hear a faint whirr sound of the fuel pump working.

My dad is a mechanic and we've narrowed the problem to- WE HOPE- a loose ground wire somewhere. Problem is, we don't know where. All of the visible ones are secure. Supposedly, there is a ground wire underneath the intake manifold on the engine block- but we can't find it.

Does anyone know where that ground wire is? We think maybe it got loosened when the trans was getting taken out.

Also, what else is under the dash that would make the fuel pump click on if I kick it enough?

Any light on this would be appreciated.

Bruce- 93 Accord- the Green Monster.

[magicdragon]

could be a bad ground underneath the dash

check the green plug going in to the alternator they can work there way out sometimes, and cause crazy things to happen even with the clusters gauges

you can replace the wiring harness in the engine bay with out replacing the rest of it in the car

i had a bad ground going to main rely and prevented the car from starting time to time and then eventually not at all so i ran a new one and fixed that problem

i know when your battery is really weak your tachometer will act crazy

i dont know if any of these helps or not but good luck

P.S. the best thing you could do is get a Hanes repair manual or a Honda service manual that has all of the trouble shooting, and wire diagrams
they're a big help

[wed3k]

fire the car up and see if it stays running withthe starter engaged. it may sound like an ignition switch.

[93GrnMnstr]

Thanks, I will check those out. My dad can access all of the wiring diagrams, so we looked at them last night, and couldn't find anything that involved both the tach AND the fuel pump.

Do you know where the ground/s is/are under the dash?

[93GrnMnstr]

@wed3k

Would the ignition switch cause the tach needle to go crazy? It doesn't seem like an ignition switch b/c lights are on and the engine turns, but the fuel pump isn't always on. Since the main relay is new, what else is going on that is making the fuel pump shut off? This is why we're thinking it's a ground issue.

Thanks for input. I will ask about the ign switch.

[wed3k]

ignition switch controls power to the gauges

[93GrnMnstr]

TURNS OUT....

The guy that put in my new clutch didn't reattach the thermostat ground wire and it was dangling loose around the trans. $82 to diagnose and tighten ground wire. Super.

I will post in prob/solution thread later.

Thanks for the input guys.

[93GrnMnstr]

Hey anyone want to put this in the Problems/Diagnosis log? I don't have access yet. I used to be a member, but had to change my email and lost my password for my old account.

[wed3k]

it's actually one of the most common thing to forget and is suggested often.