tui

So, I am new here hoping to get some help.
I bought a used 92 civic and replaced the motor in it. I know for sure the new motor has no issues. But the problem that I am having is it starts and idles perfact. Revs up in neutral no problem, but once you put it in gear and start driving there seem to be a bit of power loss and especially going uphill is the worst.
The power loss and also there is this sound when the throttle fully opens up and there is that air sucking noise.
It failed emmision on hight HC and High CO.
It has a new dizzy, new cables, new fuel filter and pump, air filter and spark plugs.
I have checked the following for porper operation, throttle body, MAP sensor and TPS sensor.
Any thought anyone. any help would be greatly appreciated.

joeshmo

Could be running lean, or bad timing. Have you checked your timing? Looked for vac leaks? Also- what motor did you put in it? What are you used to driving? Whenever I drive my truck (ford ranger 4 cyl), I feel like I have power loss but it is just the weaker engine not living up to my other cars. If you are used to driving some 300hp monster, your civic could feel slow.

tui

I replace with the same motor D15B7 and the timing is good. My other car is a 91 civic hatchback 5 speed and no power issues there.
I forgot to mention that there is no CEL at all.
I do agree with you on having been driven a bigger vehicle and noticing a power loss on a smaller could be normal, but this does not feel normal to me.
One thing that I notice is when I have it parked and press down on gas the engine seem to gasp initially and then ravs up. not sure if that is normal.

joeshmo

That doesn't sound normal to me. I've heard of bad EGRs causing gasps, but I'm not sure if that engine even has an EGR. I would at least check inches or pounds of vaccuum if you are able to.

You say timing is good, but how did you verify this? Did you check idle timing and WOT timing?

Also- did you replace your fuel pump with an OEM pump or an aftermarket? I know that the engine starving for fuel can cause problems such as this. Check your fuel pressure. You might have a blockage or kink in the fuel line.

tui

You are right, there is no EGR. I checked the idle timing but not timing at WOT. used a timing light.
Do you think the power loss would be due to timing at WOT.
I am confused.
I do keep thinking about the cat converter as well. Could it be that. The exhaust pipes do look fairly new though.
The fuel pump that I replaced is an OEM pump. I even switched the throttle body to see if made a difference. no luck

joeshmo

I would still check fuel pressure, most definitely. I had similar problems in an older car of mine and found that one of my fuel hoses had become kinked and starved the engine of fuel whenever placed under load. As I'm sure you know, engines under load require much more fuel than they do when not under load, so an engine with a fuel problem could idle and rev as high as red-line in neutral but stutter and stall or at least bog down on fast take offs and when going up hills.

As your RPMs increase, your timing should advance slightly. But unless you are running an aftermarket dizzy, I think you are probably fine. If your timing is perfect at idle, you shouldn't have any problems.

virgineg6

The engine sucking air doesnt sound normal!? Id ask if you have a stock intake but my d15z1 is completely stock, stock intake, manifold absolutely stock and i get an initial intake sound. So how is it not normal?

joeshmo

The point that the OP had to point it out makes it seem abnormal to me, even when he drives another car with a similar engine. If it were of normal proportions, I doubt it would have been mentioned. Of course engines "gulp" air when the throttle is opened suddenly, but if the gulp is prolonged, like the engine continues to gulp air but fails to use it properly, then it indicates a problem (in my opinion, a fuel problem.)

tui

Appreciate all the input here guys. I am not a qualified machenic but this is my 4th engin swap and the past 3 had been very successful.
I do agree with the air intake sound and please trust me it is not normal.
This morning I drove to work and noticed the following. When on flat surface acceleration seems normal, but as soon as I go uphill, quite a significant power loss and I have to floor it to keep going and it is at that point I hear this loud air sound.

I will definitly check the fuel pressure, but might be difficult since it will not be under any load.
Secondly, if there was not sufficient fuel delivery under load then why did I fail emmision on high CO and HC.
Both are indication of running rich, Right?