I have one I haven't run into before.
A 96 Accord VTEC 5 speed, 145K miles,
complaint: Has been progressively losing power & there is a shudder (vibration) at either around 1950 or 2050 rpm. The speed at which the shudder occurs varies depending upon if accelarating or deaccelarating. The shudder occurs with the engine out of gear, but is strong when in gear and loaded.

The loss of power has been getting worse. First noticed about 3 weeks ago.

Recent maintenance performed: (AFTER symptoms started)
Tune-up (at least new plugs & wires) - mechanic 1
Timing belts, water pump, accessory belts replaced. Timing adjusted. (mechanic 2)
Chevron Techron fuel cleaner added to 1/4 tank of fuel. (owner)

The engine idles and runs smooth/quiet except as mentioned above.

The loss of power got much worse after adding the fuel cleaner.

My thoughts:
Replace fuel filter (unknown history, should have been done at 120K miles)
Are these symptoms of a failing catalytic converter? I have never experienced one
fail.

I don't want to jerk the owner around with more trial and error attempts.
Does anyone have a better idea?

Fop


Modified by FOP at 5:29 PM 7/25/2005

 

Try disconnecting the vacuum line to the egr valve to see if the problem goes away.

 

I had originally discounted the EGR because it was an off idle symptom. We'll try that and will let you know how it works out.

Thank you

 

It may be the ports in the EGR distribution block. My 95 did that at 125K.

1. Remove the fuel rail and injectors.
2. You will notice a long plate that reaches from one side of the intake mani to the other, held down with 3-4 bolts. This is the cover for the EGR ports. remove the bolts, and remove the cover.
3. Clean the ports out with a small brush, and a ton of throttle body cleaner (not carb cleaner or brake cleaner). make sure these ports are nice and clean. If you have access to compressed air, blow the cleaner out of the ports. If not, let it evaporate.
4. replace the gasket, I think it's like $30, and bolt on the cover, and the fuel injectors and rail, making sure you have no fuel leaks.
5. Test start, and try it out.

 

Thanks to all for your help and insight.

It turns out that the new autolight sparkplugs were installed finger tight. They leaked, but not enough to hear. The leak-by heat damaged the boots and forced a new set of plug wires. The autolights were replaced with NGK plugs and performance was restored to normal.

The timing & timing belt was inspected. No problems found.

Thanks again!

 

go back to mechanic one and make him pay for his stupidity by showing him what happened.

Rule #1 don't let any one else besides a honda shop work on your car
Rule #2 see rule #1