How痴 it going everyone. So I recently purchased a 1993 civic vx with around 96k mikes on the clock. Original owner. I致e been having an issue with a loss of throttle power. I have already done the cap, rotor, plugs, wires, fuel filter, injectors, timing checked, valves adjusted, new o2 sensor. I知 gonna clean my IACV tomorrow and check the EGR. I also need to check for vacuum leaks as well. Is there anything else that I am missing to check when it comes to a loss of power. I feel a bogging slightly through the gears at different RPMs. Varies. And in 5th gear I値l be going 65 and need to pass or go a little faster and there is zero throttle response. At times if I press more throttle, it begins to go even slower. What else should I check!?

In gears 1-3 I can feel instances of slight tugs which is a little loss of power. 5th I値l be going 65 and want to speed up. I値l press the gas and nothing at all. Say I have my foot on the gas for 30 seconds for example. All of a sudden a burst of power that I assume should be the normal reaction to my foot that far on the gas. Other times I will have the foot on the gas and then I値l press 50% to the floor and it will go from 65 to 50-55? It痴 just really bothersome. Then I have to throw it in 3rd to try to get to speed. And 3rd will be slightly sluggish

Thanks again in advance.

-Ashton

 

Ashton, your fuel pump may be on it's way out. If you have the ability, check the fuel pressure. Replacing the pump is a fairly easy job, and they are relatively inexpensive. You may just want to go ahead and replace the pump with a quality unit. I would recommend trying to clean and re-use the OEM sock on the pump you remove. Most of the aftermarket socks I've seen are oriented incorrectly, and I've personally experienced the pump starting to draw in air due to the aftermarket sock at only 1/2 tank. Thankfully I had kept the old sock and was able to put it back in.

 

Also, your injectors could be partially clogged and the VX is known for a stumble on vtec-e crossover. The VX needs clean free flowing injectors to run well. If they aren't atomizing well it can seriously impact how the engine runs, more so than other motors.

 

Definitely clean the EGR system.

CEL codes?

Have you checked whether the cat is clogged and whether the FPR is working properly?

 

I think you are feeling lean burn. If it is a 49 state VX with the 5 wire wide band oxygen senor it will drop into lean burn at specific engine loads. Feels like loss of power and an unresponsive throttle. And when it kicks out of lean burn you get a rush of power.

I have a VX, I am very familiar with that feeling.

But at the same time the VX is VERY picky about everything being just right. Those EGR ports are a real pain to get to as they are welded shut. I recommend some 1/8" aluminum pipe plugs to cap off the access holes after cleaning to make the next service easier.

Also dirty fuel injectors will cause odd problems. VX had unique 190cc injectors not the common 240cc injectors.

Also make sure it has a factory or NTK oxygen sensor. They are $$$ but they are the only ones that work properly. Old or low quality sensors will be sluggish to respond and aggravate the lean burn condition.

 

I was thinking about this as well. I was hoping that the o2 sensor was the issue. Then it was replaced and still had the issue. It also feels as if it also acts up more if it is really hot outside.

 

I just bought brand new injectors because I also thought this was the issue. They aren稚 oem but they are a proper flow rate and are rated at 190cc as stock.

 

no check engine light codes at the moment. I recently went to a muffler shop that said the cat was still working as it should. I had a minor exhaust leak that was fixed by replacing the 1 1/2 nice piping and resonator.

I am going to take the egr valve off and clean it. Will carb cleaner be good enough for the cleaning process? And I need to check the fuel pressure regulator. I just bought a new coil and igniter because I had a feeling that could be the issue also. Still have some work and research to do. : /

 

yeah I have the California version. So I am using the denso 4 wire o2 sensor. I just replaced it. I have new 190cc injectors as well. Still have to clean the IACV. I知 gonna change the pcv as well. Have an igniter and coil just to finish off the spark just in case that is an issue. Just been a pain trying to figure this out. Really do appreciate all of your help guys!