I have a 1999 Honda accord ex v6 that surges intermittently when it warms up but does not have any fault light. Any ideas?harold

When you say surges I take it you mean that the RPM's are going up then down? Try cleaning your Idle Air Control Valve. Here's a short "how to" video: http://www.youtube.com/watch?v=gOECtpdfqyk

Thanks for the suggestion. I replaced the entire throttle body, cleaned the IAC, replaced the distributer and the roto, the fuel pump relay and the ignition electrical body. The car runs good idling. The problem surfaces when the engine is warm, that is, it loses power like it is not getting any gas. I press the gas but nothing happen then suddenly it kicked in and run good then it happen again. the RPM drops when this happens. It acts like when it gets hot something closes off and when it cools off it reopens. This usually happens when on the highway. I let my foot off the gas and the car coasts with no problem. as soon as I put my foot back on the gas it reoccurs. Could it be after the fuel pump been stressed for a while it becomes intermittent? This is very difficult to diagnose. What makes this so difficult is there is no CEL. I took it to a Honda garage and they don't know what's causing it and they want to keep it to try different things. That would cost me for every item tried even it did not fix the problem. HELP!, HELP!

Sounds like a bad TPS. Throttle Position Sensor. I was checking out some sites and I ran across one where people were having a similar problem as you. Apparently, when doing some major repairs, the MAP sensor and the TPS sensor where accidently plugged into the wrong connectors. They are very close to one another, and they are identical connections. Very easy to plug one into the other. Here is the site: http://autotechdiagnostics.com/?p=344 If you didn't mistakenly swap the plugs, you may just have a bad TPS.

Thanks, I changed out the entire throttle body and no fix. The connector to the MAP and The TPS are the same but the location would be intentional to swap them. Could a O2 sensor cause this? How about the CAT? Thanks, Harold

A bad O2 sensor shouldn't affect your power. I have a bad O2 sensor on my Camry right now. No loss of power. Your Cat may have started to plug up. You could just unbolt it and let it hang down a bit and give it a test drive to see if you have full power again. A quick change of the O2 sensor wouldn't hurt. Since you have no CEL, it's pretty much anyone's guess. When you changed out the throttle body did it come with a new TPS?

Yes. The TPS on the throttle body is put on with non removable fasteners and the iac sensor with 5 point torx tool. They were put on to not be serviced by owners.

The only other thing I can think of is the VSS. Vehicle Speed Sensor. Have you changed that out also?

No. Is that part of the transmission? thanks, Harold

It fits into the transmission. You can go to Youtube or Google and type in Accord VSS location. Most models you can reach it from the engine compartment. Here is a site that lists the symptoms of a bad VSS: http://www.ehow.com/facts_6779778_symptoms-bad-speed-sensor.html

Reelin68, Thanks for your reply. I disconnected the o2 sensor before the CAT and ran the car for about 30 miles and the problem seems to have gone away. I will replace the sensor later and let you know what expired. I now am getting a P0135 code but that is because of the disconnected o2 sensor. Thanks, Harold

Well that's a relief! What an easy fix!

i have 99 honda accord an its running rough no power an it shakes when idling can you help an tell me how to fix it

If your check engine light is on, I would have the codes scanned first. That should pin point your issue. If no check engine light, it could be numerous things. For starters, I would buy some throttle body spray cleaner. Spray the cleaner into your intake and see if there's any improvement. You may want to do a basic tune up as well. Plugs, wires, fuel filter, air filter, cap, rotor. Spray some cleaner into your EGR valve also. If plugged, that will cause performance issues as well. Post back with results.....

I'm having the exact same trouble with my 2001 accord v6. I've taken the intake manifold off and cleaned the EGR valves and it allowed me to stretch the RPM to about 3,000 Then, I replaced my Vtec solenoid and it allows me to stretch to about 3,500 RPM BUT.. I still get the power surge if I try to open her up on the highway And. If I'm in park and try to allow the RPM to stretch.. the pop and surge are there at 3,500RPM has anyone locked down a solution to this?? Is it a computer issue?? Fuel pressure issue?

Tatdrews, Have you tried replacing the MAP sensor?

I haven't done that yet... it was one of my first ideas to do as a fix Figured with it not getting to vtec mode I'd clean out the EGR and replace the vtec solenoid .... I was thinking fuel filter and fuel pump possibly as well? Think the MAP sensor would fix it?

One of the signs of a bad MAP sensor is the surge issue. Have you checked for error codes yet?

I have checked for codes, but only the 02sensor comes up (test pipe from headers)

1999 Accord 3.0 with really bad throttle control and idol once fans start up. I chased the problem by installing IAC valve and replacing the Throttle position sensor. also replaced the throttle body hose as it was cracking. All that did nothing. Then I tested and burped the radiator/coolant system. Did nothing. Called auto parts shop that sells to mechanics almost exclusively. The salesman asked me to come in and he would show me what he thought it was from his experience selling tons of and it fixing the problem. Ignition Relay. he even put it in as it was a 3 min job. fixed the problem. $50. part 3 min to install. after chasing a problem with lots of parts and time the real solution was a parts counter salesman who knows what he is talking about. I hope this helps others.

Main fuel relay. Had the same problem, pulled and opened the relay, resoldered and wala, no more probs.

My car has this same issue also a 99 Honda accord ex v6. Did ya ever figure out the issue if so please email me kasijanna06@gmail.com

After tinkering and replacing everything for nearly 2 years, I Finally found the problem...there was a corroded wire...of all things a very easy fix. After I replaced the entire computer and ignition,intake manifold,throttlebody,map sensor,intake,fuel pump,fuel pressure reg..... the list goes on and on and on. At least it's a honda and easy to work on...and now everything but internals is brand new hahahaha

What wire was corroded? Please email me kasijanna06@gmail.com

Same question: what wire? BTW the problem stopped when the weather got cooler. So it is still there waiting for the summer to come back.

Ot was the power word running to the vtec solenoid

Horrible type hahahaaa power wire..running I to the vtec solenoid...its probably commonly corroded seeing there was nothing protecting the wires

Did the car ever have the issue again after the wire was fixed??

Mine is only seeming to do it right after first started acts like it's not getting gas then all the sudden flus like it got all the gas suddenly then no problem after that until I start it again

I never had the issue again after replacing az conv that wire

I've been having the same issue as Kasijanna06 ...seems to only happen when I'm first getting going on the road (I usually let her warm up a bit before taking off) then it's fine... UNLESS I stop somewhere and turn it off, say pop in somewhere to grab something, then starting it again when it's already warm. Doesn't like to pick up speed will kind of lag then kick in and be fine again. Intermittent issue. Doesn't act up as long as the car stays running. It's only after being off and seems more likely if it had already been running and is being started warm.