Honda Civic 2001 won't accelerate after 20 mpg
 

Hey guys,

I just recently bought a Honda Civic Coupe 2001. It's a 4 cylinder: automatic.
I changed the spark plugs and did a tune up and now the car vibrates a lot, it feels/sounds like it will stall soon, and no matter how much I accelerate.. it will not go over 20 mpgs. I installed a new idle control valve but the problem persists.

It would be great to have some feedback of what I can do!

Thanks!

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

So.....exactly when did this problem start?

Did it start happening right after you did this

What are you calling a "tune up"?
What all parts did you touch?

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

I put in new spark plugs, did a oil and transmission changed, added new spark plug seals, and that was about it. I made sure to label all the ignition coil just in case I stuck it in the wrong place so that shouldn't be the problem. Thanks for you reply!

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

So....when did this problem start?


Got CEL codes?

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

Is there any chance that your car overheats? have you had a full fledge drain/fill with ATF. when was the last fuel filter change? it comes with a strainer that also needs replacement. Also, Fuel Pressure Regulator needs a very thorough cleaning. I hve a 03 civic ex and its got exactly the same problem. (the car vibrates a lot, it feels/sounds like it will stall soon, and no matter how much I accelerate.. it will not go over 20 mpgs. Mine on freeways does not exceeed 40mph). I push down the pedal and pull back and push back again the pedal and it does go beyond 40mph sometimes. It depends if i have driven over 50+ mi on a very hot afternoon.
I had IAC valve cleaned but not replaced, spark plugs changed map sensor cleaned & replaced needs a thorough throttle body cleanup with EGR valve as well.
If all this doesn't change anything i then move to change both upstream & downstream Oxygen sensors.

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

My car 03 civic ex does not accelerate anymore even after all the work on fuel filter, o2 sensors and cleaning on IAC valve/throttlebody/egr valve/map sensors is done.

What would stop acceleration?? spark plugs, head gasket transmission issues???? overheating.

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

Do you have a CEL?

If your car is an EX, as you mentioned, VTEC not working properly will put the car in a governing mode to prevent damage to the engine. This means only allowing the car to accelerate up to 3,000 RPM I believe. I'm not a 100% on that.

Have you done proper oil changes on the car over the years?

Passages in the VTEC solenoid could be restricted or blocked all together. VTEC also has it's own oil pressure switch as well. It also has a small screen filter assembly as well.

Below is a drawing of the VTEC cylinder head. Piece 9 is the VTEC assembly and 10 and 12 are the filter and pressure switch.

http://www.hondaautomotiveparts.com/...EAD+%28VTEC%29

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

I am getting the following CEL Codes on my 2003 Honda Civic EX Sedan
P1129 (Map Higher than Expected)
P0730 (Faulty Shift Control Problem)
P0505 (IAC circuit condition higher/lower than expected)
(Vaccum Leak On Engine, Dirtry Throttle Body, IAC motor defective, Poor Electrical connection to the IAC valve)
P0141 (HO2S12 heater condition Bank1 Sensor 2).

Very regular & particular about getting oil changes every 2500 mi. Never to exceed 3000mi.

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

Hey guys!

Thanks for responding. I couldn't figure out the issue so I had a mechanic come over and look at it. It turns out that the "Top Dead Center" aka camshaft position sensor was the problem. The car doesn't vibrate anymore and it drives like normal again.

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

We are seeing exactly the same behavior on our 2002 Honda Civic LX coupe. On hot days, after 50+ miles, it seems like the engine can't get enough power to accelerate past 20 mph or so.

We had the timing belt (+water pump + tensioner + blah) replaced, and that obviously didn't fix anything...

I saw the OP replaced the camshaft position sensor -- is that the same resolution for the above poster?

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

How did the routine tune up messed with the TDC sensor? Did the OP had the car running while the sensor was out? Replaced it after the ECU was on the limp mode?

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

My car 03 civic ex does not accelerate anymore. WIRING TO MAP SENSOR, VALVE COVER GASKET & BROKEN MOTOR-MOUNT REPLACED.

What would stop acceleration?? spark plugs, head gasket transmission issues???? overheating.

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

sounds like a bad spark plug to me
or bad gap

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

...
if all you can get is 20 MPG, you accelerating too much...
...

Re: Honda Civic 2001 won't accelerate after 20 mpg
 

Have an 2001 Honda civic ex on hot days car will out of the blue start not wanting to accelerate over 40 mph let it cool down and runs fine