Hi, i have an 89 Civic LX,the only changes done to the motor is a header and a custom exhaust, short ram intake. The motor (for now) is a D15B2 w/ Dual point injection.
For a while now my car off and on would bogg at high rpm's. Sometimes it would go to the Rev limit and kick back, other times it would get close and hold but loose power. Then 2 weeks ago i noticed the bogging starting earlier closer to like 4800-5000 rpms. This past it starting just bogging anytime it got close to 3000 rpms, maybe even less. If i hold throttle, while car is in neutral, it will continue to weaken to the point of stalling out. It also makes a loud growling noise, and a hissing noise. I also noticed before it got this bad that going up hills the car would begin to loose power also. If i hold my hand near the intake filter while it's under throttle it pulsates, like the air it is being forced away from the filter, or that the suction isn't consistant so the pulse is felt from the air being sucked in on and off again creating a vaccum wave. I've also noticed a strong gas smell, like the gas isn't being burned up, but theres no smoke coming from the exhaust. The computer is throwing no codes at all.

I went ahead and replaced the spark plugs, the cap and rotor. The plug wires where just replaced a month ago. I've checked for spark at all 4 plugs, which there is. When i pulled the plugs they were black, also 2 of them had a brown ring on the porcelin where it meets the metal. The cars tempature gauge never changes stays where it's suppose to be. I then checked the distributor. First i noticed damaged to the cap, also the rotor had bored out it's screw hole causing the rotor to have play damging itself and the cap. Literally chunks of plastic where missing. Replaced those parts and the car idles beautifully. But continues to bogg when throttle is applied.

I'm not sure where to go from here. I'm going to try replacing the plug wires and distributor next.
Could a gasket, such as a rotted TB or Manifold gasket cause this kind of problem. Creating excessive air smothering the motor?
I could use any help I can get . I moving in 2 weeks and this car has to drive almost 1000 miles to get me there. So time is a factor also.

Thanks-Jason

 

fist off, whats the last thing you've changed / modded on the engine ?

i see that you have a short ram, did you maybe bump a vacuum line loose when you put that on ?

if it were me, I would take the distrubutor off the engine, check to see if it spins frely. sounds like the distibutor bearing might be going bad, causing the shaft to heat and melting the rotor , is happened to me before.
It is going to be easier to replace the distributor with used/new than disassemble the whole thing just for the bearing. plus theres sensors inside there that are calibrated and you need to put them back just as they were or it will run like ****.

second, do a compression check, then a leakdown if the compression check is acceptable. check the coolant and the oil. sounds like you might have a dead cylinder, or a bad valve on one of your cylinders.

Third. check/replace the fuel pressure regulator and check static fuel pressure. make sure its not a problem w/ the pump or supply/return.

good luck

 

I've checked all the hoses. All the mods where done w/ in a week of each other and then I took a trip put about 600+ miles on it since. Ran strong then, but w/ in the last 3 weeks is when i began it's steady down ward spiral. It had a noticeable tap or valve chatter before, but now has quieted. Then again since it won't rev much and the noise is overly loud it's hard to tell.

I forgot to mention that the head appears to be heating up alot, the whole inside of the head is a deep gold to light bronze color. Also the valve cover inside top is black, like oil is cooking on it. But my car temp gauge never says that the car is running hot. So is it possible the heads over heating w/ out the car registering it?