Heads on but running real Bad?

[Cfmotorsports]

Hear is waht I have its a 90 civic dx 1.5 the head was trashed so i had a good 1.6 head off my old si motor i had asked on here before and was told it would work. well i swapped it on to the 1.5 motor no problems bolt straight on put timming belt set everything up like it should be fired it up started on on the 1st role nice and smooth no missing rough idle or anything so i let it warm up fill the anti freeze up. cap it off still nice and smooth now i procede to give it throtle. if you give it throtle fast it bogs out real bad almost cuts off kinda sounds like it backfires threw the intake if you ease on the gas it will rev up to about 3500 rpm and then start messing up what could the problem be.

thanks for any help
chris

[alexdog69]

Did you set your ignition timing?

Are you still using DPFI?

This is a Si head on a D15B2?

[91civicDXdude]

it sounds like a timing issue to me. double check the cam timing, make sure its properly set, then recheck the ignition timing.

which cam gear did you use on the si head? I've heard the Si cam and DX cam have different timing..

Are you certain the head itself is good? Does the car maintain bubbles in the coolant, if so the head and/or head gasket is bad..

[stealthZCcivic]

i did the same thing on my old car, i ended up having to swap the old dx cam into the si head and it was fine after that.

[Cfmotorsports]

Yes i am still using the DPFI, i played with the ignition timming did not make any real differance
The head was good on the last motor no signs of a bad head gasket as far as coolant goes>
I am not real sure wich cam gear i used i think i used the one off the 1.5 If the cam timming is differant then what should i do or were would i go for the information to fix the problem i know people have done this before so not sure what the problem is, it is not throwing any codes eather.

as far as changing the cams out and intalling the one out of the 1.5 in the 1.6 head what al would be required to do that just a cam swap and and readjust the valves.

thanks chris