I just bought a immaculate 1989 Honda Accord DX with 415,000 for $200! It's a one family owned car with service records going back as far as 2010 with 295,000 Miles when the engine was rebuilt. It has a carburetor and no code light on the ecu.

The car start and runs great when the engine is cold with plenty of power in all RPMs. The issue only starts when its warmed up. For example, when I drive to the store and come back out, It has a bit of trouble starting but I can always get it started. Once it starts, it idles fine. If I give it some gas in park it will start to bog around 2500 rpm like it has antilag! When I'm driving and give it some gas to maintain my speed, It will accelerate for about .25 seconds and then bog down like I'm running out of gas. However, I can Pulse the throttle by stomping on the accelerator petal several times a second(see video) and each time I step on it, It won't bog for each .25 press, letting me slowly speed back up. I though it might have been fuel issue but, soon as my rpm is at about 2600 rpm, I can full throttle it and "power though" the bog to a strong motor all the way through the RPMs. And sometimes after the car has been bogging, It will magically disappear only to resurface minutes later.

I know the fuel pump and fuel filters have been replace by the last owner to attempt to fix this issue. The service history shows the rotor, cap, spark plugs pcv valve being replaced 85k ago. I just changed the spark plugs but that didn't change anything. Given that it is a issue and can show up and then disappear minutes later, makes me think its some sort of solenoid sticking. I almost think it reappears after coming to a stop.

Being able to pull code on BMWs has always pointed me to the the issue on my personal car or clients cars. This is something I have taken for granted. I have not idea what to test. Any help would be appreciated because I don't know where else to look for.

Link to Videos

 

I think the 89 DX accord has a carburetor. Does your car have a carb?

 

Yes it has a carb. No code light on the ECU either.

 

IIRC, the ECU on the 89 accords was under the driver's or passenger seat and had a window on the ECU, where a light would flash a code. I'm not sure if the carb version had this option.

Regardless, I'd start with the easier stuff. There should be a sticker under the hood showing the routing of the vacuum hoses. If the vacuum hoses are original to the car, the hose should have a number printed on the hose. I'd check the routing of the vacuum hoses and inspect all hoses for deterioration/rotting that would cause a vacuum leak.

 

I checked that the vacuum lines have been replaced before. Also replaced the spark plugs and coil. What should I test?

 

Were the spark plugs black on the ends of them? If they weren't then you need to put focus on the carburetor. Have you check the accelerator pump and or made adjustments? Have you had a look at the FI pressure regulator also?

 

The spark plugs were a mixture of black and white when I had swapped them out out for new ones. As far as the accelerater pump goes, isn't that just used in the breif moment of idling and full throttle because for about half a second of stomping on the peddle it works fine then dies down. I'll check into the fuel regulator