Mechanics

STARTS, IDLES ROUGH, DIES ON ACCEL

1994 Honda Del Sol

Engine Performance problem
1994 Honda Del Sol 4 cyl Two Wheel Drive Manual 160000 miles

If this car had a carburetor, I'd say the passing/acceleration passages were clogged.

It starts, idles rough (as if the choke is not working) would die if the pedal is not tickled, idles better warm and will not move forward unless the pedal is pumped to get revs up. Absolutely no power.

These symptoms have to point to a very specific part of the Fuel Injection system, No?
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Yazro
September 15, 2009.



Hi yazro,

Possible causes for the problem are: 1. Unequal compression. Valve clearances might need adjustment. Get a compression done if all others checks out ok.
2. Faulty Throttle Position Sensor.
3. Low fuel pressure.
4. Bad spark plugs, wires, distributor cap, rotor, ignition coil.
5. Valve timing out of sync. Was timing belt replaced?
Is the Check engine light showing?
Was anything done prior to this happening?
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KHLow2008
Sep 15, 2009.
1. Unequal compression. Valve clearances might need adjustment. Get a compression done if all others checks out ok.

I agree this would be a last resort since I parked one day and a few days later the problem occured.

2. Faulty Throttle Position Sensor.

That could be the problem. I got 5V for the baseline but I could not get a reading with my Voltmeter with the engine running so will try that again.

3. Low fuel pressure.

Possible but when I took the cap off and turned the key on. Fuel spurted out 6" in the air so there is some pressure.

4. Bad spark plugs, wires, distributor cap, rotor, ignition coil.

I did recently replace the coil when it died on me while driving, but cap, rotor, plugs and wires does not seem to fit the profile.

5. Valve timing out of sync. Was timing belt replaced?

Don't know the history of the belt but again seems unlikely given the suddeness of the issue, which would indicte more of an electrical/electronic issue.

Is the Check engine light showing? Check engine light goes out as it should. No codes when jumpered.

Was anything done prior to this happening? - Just the coil.

You are leaning to the throttle position sensor as opposed to any other fi sensor? Like O2 sensor or MAP? Thanks for your help.

Tiny
Yazro
Sep 15, 2009.
Sorry if I missed this out. You mentioned it starts idling rough when cold. That should not be the case as the fast idle valve should be operating and the idling speed should be at more than 1000 rpm.

If this is the case, the most likely problem is engine compression. Check tha valve clearance, tight valve clearance would cause such problem.

If you have coolant depleting and/or overheating issues, you might have a bad head gasket.

KHLow2008
Sep 16, 2009.

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