KA24E Bogging Issue

[Apex Eight]

Please read this long post in its entirety if you decide to comment in this thread.

The single cam KA in my S13 bogs when started cold. It starts just fine but bounces around at low RPM for about 5 seconds during cold starts. The issue is non-existent when the engine is warm.

The engine recently had its timing chain replaced along with new chain guides, sprockets, a new water pump, oil pump, distributor cap, rotor, and plug wires. I was told by my mechanic that my engine was timed correctly after the timing chain replacement.

When I picked the car up from the shop, my mechanic told me the fan clutch was on its way out and that I needed new plugs. Well, later that same day, the fan clutch went out and I had to replace it in the parking lot of an Autozone. While doing so, I had to disconnect the upper radiator hose to remove the fan shroud to get to the fan clutch. So undoubtedly trapped air within my cooling system.

The next day, the bogging issue occurred.

After a couple of days of doing nothing to solve this problem, I tried starting it one morning and instead of having the RPMs go up after a few seconds of bogging like it usually would, the engine bogged for a few seconds and died. After a few more tries, the engine would keep dying after bogging. I then took my moms car to Autozone and bought some plugs. The old NGKs that I took out looked fine. And while I was replacing them with the new Bosch plugs that I bought, I was thinking that they wouldn't make a difference. Well, after replacing the plugs, the engine started right up and didn't bog one bit. I thought the issue was solved.

The next morning, the issue occurred again. So I took the car back to the shop that replaced the timing chain and explained the situation. He told me that air trapped in the cooling system could give a false reading to the coolant temperature sensor and thus cause the bogging issue. He "burped" the cooling system and got air out of the system. I do not know if he was able to get all of the air out.

The bogging issue persists during cold starts.

One of the "towers" on my distributor cap is scarred up from me trying to over-secure one of the plugs wires to it right after I installed the fan clutch that day. Stupid me, I know. I just decided to add this part in case it could be the culprit.

Also, I can hear one of the engine's lifters ticking. Not sure if that could cause this problem, just trying to be as detailed as possible so I can receive the right advice.

I'm really thinking about using a bottle of Sea Foam... A third of the bottle through a vacuum line, a third in the gas tank, and the final third through the valve cover. I just don't know which vacuum line would yield the best results

Help me out here guys!

[h2v7]

the vacuum line off the brake booster works fine for seafoam.


sounds like timing mayybe />/?

[Apex Eight]

the vacuum line off the brake booster works fine for seafoam.


sounds like timing mayybe />/?

Thanks, that's what I did with my old Integra so if I ever do seafoam it, I'll do that.

The car is actually back at the shop now. I talked to my mechanic and he brought up the possibility that the injectors were leaking. While the car would sit over night, gas would leak into the cylinders and when I would go to start it the next morning, just too much fuel. I'm thinking this is the culprit. Could also explain why the plugs I took out had some liquid on the electrodes which is. Stupid me for not smelling to identify what it was. I immediately assumed it was oil lol. Explains why the new plugs seemed to be the fix.

We'll see how it goes and what the shop says