I did a jdm sohc vtec (D16a) swap into a 99 dx coupe. Car is sputtering when u hit the gas and will bog out if you hold it. Changed the harness, distributor, and checked everything I know of. Any suggestions, thanks

 

Check the fuel pressure. You might have a bad fuel pressure regulator.

 

Or an injector problem.

 

The people at the shop said it is holding fuel pressure, just not enough fuel is getting to the injectors. He put fuel through the engine manually and it ran fine. They think it is electrical problem, but no cel are coming up. I need this car by tomorrow afternoon, so any help is great. Thanks

 

try changing the ecu if that does not work try to advance the timing a little

 

Don't expletive with the timing. Are you sure that your fuel pump is healthy? If you think it's an electrical issue, why don't you look into that?

 

If there is adequate fuel pressure at all times, then there is not a regulator or pump problem. IF it were true that not enough fuel was getting to the injectors, then a clogged fuel filter would be the likely cause. Having adequate pressure, but not enough fuel to the injectors is not only unlikely, but pretty much stupid. Injector or PCM problems are possible (and are electrical problems too).

 

We have tried changing the ecu and I dont think that worked. I believe they also messed with the timing and it didnt help any. Ill let them know about looking at the fuel filter and injectors. Whats the PCM? Idk it just seems more complicated than all that, but thats what I thought it would be. Thanks guys

 

PCM is another name (actually the correct name) for an ECU. What do you mean by you don't "think " it worked? Did the code come back? Faulty injector(s) can lean out the system and throw a code. If the ignition or cam timing is off, that could cause the problem too.

 

The last time I checked with the shop there was no code being pulled. I wonder if it could be the cam timing? I just hope this can get fixed fast.

 

what injectors are you using?? The ones from your dx, or the ones that came with the engine? What computer are you using?

 

how do you know its running lean? have you checked spark and fuel? Im sure its getting air, sounds like ignition misfire to me.

 

I am using the injectors that came with the jdm engine. I had this enigne in my hatch and it ran fine, but when I put it in the coupe it started doing this. As long as you pat the gas and get it past a certain rpm it will run fine. I am using a stock p28 with the obd2b-obd1 jumper harness. The reason im saying its running lean is because its like studdering when you hit the gas. But I thought there would be a code for that. Idk, I just need to get this fixed. Thanks for the help