I'm new to the site so please excuse the length of my post.
I have a 1994 honda prelude 5 speed. Before I purchased it someone took a h23a3 block and put the h22 vtec top end on it. It has a p13 3 prong computor on it. And it has an external coil on it, and there are a few plugs and wires that aren't hooked to anything. My only dilemma is the fact that when I go to start the engine when it's cold, it gives me a fit, and I meen it will not start...nut once the engine is warmed up, it starts and runs perfectly as it should, I've exhausted every option I could think of, but I am new to Hondas and I cant find absolutely no answers on any forum as to why, or any info on my engine to figure out the problem. Some one please help... Thanks.

 

Obviously you need to find out what is not hooked up. Or you can do nothing and always wonder what the issue is.

 

Possible routes you can take:

1. You could refer to a wiring diagram. There are free prelude service manuals online.

2. Research. Within the past five minutes I was able to find this:

https://honda-tech.com/forums/honda-prelude-4/how-h23vtec-h23-vtec-h23-vtec-search-friendly-510617/

You could possibly reach out to individuals who posted and get help.

Good Luck.

 

main relay

 

 

I appreciate it guys, like you said I need to figure out what's unhooked and get it wired up before I can make any usumptions, and thanks for the wiring diagram

 

As was suggested, hook up all wires.

For what it's worth, I have an '89 Prelude Si that once stopped starting when cold. Over 23 years I never had that problem. It would start but only with much pumping of the accelerator. Once it warmed up, no more problem starting. (ECU using default values, I presume.)

It turned out the lead to the TW sensor was broken so no signal to the ECU to tell it that engine is cold. Fixed the lead, Miller time! I don't know how a '94 is wired but if it's got something like a TW sensor, make sure that's one of the wires that is attached.

 

Not sure that pumping the gas was doing anything except opening and closing your throttle plate. PGM-FI engines dont squirt fuel in the engine when the thing is off.