OK, so last week my CEL popped on with the dreaded code 43. after seeing numerous replies to replace the O2 sensor that's what I did. the CEL is gone, but now my car is missing badly all the time. I start it up, it sounds like its skipping at idle, even my tach is bouncing. I drive it and it sputters as I am accelerating. I slow down and stop at a red light and it still skips. Normal steps have been taken. Dist. is brand new, so is cap, rotor, plugs, wires. Fuel flow is good, injectors not clogged, no vacuum leaks, no oil/water mixing. I am at a loss.

 

Suggest checking that spark plug leads are correctly routed from distributor to spark plugs. A problem here would result in two cylinders missing. Firing order is 1-3-4-2. Distributor should have some indication for #1 cyliinder. Cylinders are numbered from 1 on driver's side to 4 on pax side.

If wires are correctly routed, then try a balance test. Remove a lead and listen for a change or no change in engine miss. If worse missing, cylinder is performing. If no change, something is wrong w/ the cylinder being tested. Possibilities are leaking valve, blown head gasket, low compression, and bad spark plug/wire.

good luck

 

everything is routed correctly, all plugs and wires are firing, nothing amiss in the cap or dist. if I unplugged each cylinder it ran way worse across the board.

 

If you've checked carefully and all plugs are firing and on time, then suggest to check engine cylinder compressions (135 psi min, 178 psi nominal, max 28 psi variation) and fuel pressure is w/i spec (35-41 psi).

good luck

 

Fuel pressure looks good, havent gotten to the compression due to weather. would a bad IACV cause that sever of a miss at idle? its no longer stumbling accelerating.

 

I've never seen IACV problem cause a miss. It causes low idle speed if stuck closed or high idle speed if stuck open.

A severe intake air leak might cause a miss, particularly if it affected only 1-2 cylinders.

Is miss a "dead miss", misses every time cylinder fires, or random miss?

Tach irregular movement is usually symtomatic of a problem w/ ignition; ignitor, coil, wires, plug. Do you have external or internal coil distributor?

good luck

 

it seems like more of a random miss, but its very pronounced, like you can sit at the exhaustpipe and hear the miss popping out of the exhaust. the tach does bounce when the miss hits. its an external coil which is new, along with distributor, dist. cap, rotor button, and plugs. all less than 6 months old.

 

I asked about my IACV because when I unplugged it to see if the idle would smooth out, the car died, and would not start unless I plugged it back in.

 

When you performed a balance test, the miss got worse on every cylinder?

Compression test should be performed to rule out leaking valves or simply worn engine.

IACV unplugged may not pass enough air to sustain engine. Actually, this is a positive sign in that it means the IACV is working to maintain idle speed. However, stable idle should be possible w/ IACV unplugged. You need to clean IACV, throttle body, throttle plate (both sides), and if idle is still not possible, the idle air bypass screw (TDC of throttle body entrance) should be adjusted to maintain a stable idle of 600 +/- 50 rpm w/ IACV unplugged.

good luck

 

yes, every cylinder I unplugged the car ran way worse. that whole idle procedure I have already performed as well, I had to replace my intake plenum gasket a few months back and I had to re set the idle, the car ran then with IACV unplugged.