Fuel pump went bad changed it now runs rough not drivable

Tiny
COE4669
  • MEMBER
  • 2001 HONDA CIVIC
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 127,000 MILES
Had my 2001 honda civic lx diagnosed at honda dealer with a bad fuel pump and regulator had it changed and now it is not running right it has rough idle and the computer would not pick up any activity at all to do with the sensors. The mechanic seemed to think it was something to do with the ecm. But it seems like fuel pressure any ideas? I had new keys made and programmed to car a while back at honda would the ecm have anything to do with it or is there someway to reset the pump
Sunday, August 14th, 2011 AT 12:43 PM

7 Replies

Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Check for bad fuses and try resetting the ECM by disconnecting the battery negative terminals for a few minutes.
Was this
answer
helpful?
Yes
No
Sunday, August 14th, 2011 AT 12:52 PM
Tiny
COE4669
  • MEMBER
  • 3 POSTS
The car ran fine before the pump and regulator was changed the car surged a little when accelerator was pushed. Now it wont idle good unless he squirts a little gas in then it clears up. Didn't know if I got a bad pump or not. I don't think he has unhooked the battery since the new pump has been put in. Could that cause it to run rough?
Was this
answer
helpful?
Yes
No
+1
Sunday, August 14th, 2011 AT 1:12 PM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Yes, low fuel pressure can cause that. Have the fuel pressure checked. There could be some installation fault resulting in pressure losses.
Was this
answer
helpful?
Yes
No
+1
Sunday, August 14th, 2011 AT 1:17 PM
Tiny
COE4669
  • MEMBER
  • 3 POSTS
I was told that their could be ground problems with the pump also. So if the car starts can you rule out problems with the ecm. What would cause him not to be able to trace any sensors through his computer hookup.
Was this
answer
helpful?
Yes
No
Sunday, August 14th, 2011 AT 1:31 PM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
That is the reason I suggested checking the fuses. If the Data Link Connector is not being powered, ascan tool would not be able to connect. A faulty ECM would cause that as well.

You need to go step by step.
Was this
answer
helpful?
Yes
No
Sunday, August 14th, 2011 AT 1:56 PM
Tiny
INFOSHREDDER
  • MEMBER
  • 1 POST
Wow! I have almost the same problem. 2001 Civic EX. My Fuel pump died. Had it replaced, now the car is really rough at idle after it warms up. CEL came on and the codes indicate misfire on all 4 cylinders. I reset the ECM/ECU whatever and it actually got a little better. Put in a new air filter and the problem came back. I'm not sure if that was just a coincidence or not, so I'm going to reset the ECU again.

I'm not sure what to test next.
Was this
answer
helpful?
Yes
No
-1
Monday, September 19th, 2011 AT 5:26 PM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Test the fuel pressure. It is possible the fuel pump was not installed correctly.
Was this
answer
helpful?
Yes
No
Monday, September 19th, 2011 AT 6:22 PM

Please login or register to post a reply.

Related Fuel System Fuel Pump Not Working Content

VIEW MORE