[curvy95honda]

Blew the engine in my 95 coupe and headed to get a replacement. The most inexpensive option is the JDM version which is right around $600 just for the parts. The wrench who I consulted about the swap, pretty much took care of the entire swap. Drove the car home a few days later.

After driving the car for a few days I noticed there wasn't as much power as there used to be. When I step on the gas, my car kinda slugs along then kicks in and delivers the goods at around 4000 r's. I don't really notice it using normal driving but, when I am in a hurry, I really notice it because my car just doesn't move like it used to. Nothing mechanically wrong, in other words, this problem is not stopping the car, it just doesn't act right.

All of this was a year ago, at this point, the car has been getting progressively worse and is now shuttering and shaking so bad, I can't even take it on the freeway. Accelerating for that matter makes the car stammer and shutter; just really, really bad on the freeway.

Now, I am frustrated. I have taken the car to Honda, local mechanics, transmission shops and close family friends, including the wrench who did the transplant. No Help! I have got everything from replace the o2 sensor to the battery is bad. I have replaced tons of parts on this car and am now exhausted from this fiasco.

I have narrowed the problems down to two possibilities.

1. The original engine that came with the car was swapped and the new engine doesn't carry the same code as the previous engine. A D16Z6 is the apparent choice for this car (at least the 1.6l option is the only one Honda will give me when I enter my vin# to search for parts) however, the transplanted engine is now a D15B. The ECU doesn't seem to be replaced as the dust on the unit looks about 20 years old… Does this even matter? If the wrench swapped out my D16Z6 with the JDM D15B, would I even need to use the JDM ECU, to accompany the new engine? Would this be the cause of my problem?

2. So, in researching other problems that are happening with the car, one of them being the fact that my cruise control suddenly stopped working, one of the troubleshooting tips in the Chilton book was the possibility of a vacuum leak. Since my car is totally incapacitated now, I am adamantly researching this problem and I run across a generic online troubleshooter for car problems. After I told the troubleshooter what was going on with my car (as I stated above), it said "have a mechanic check for vacuum leaks". Could this be the source of my problem?

My question is: Which one is it or is it even any of these options? I've been at this for two days straight now and can't seem to find anything on the subject. Any help or insight would be appreciated.