hey i have a 91 civic with a 91 ls swap. lately its been fuckin up. when i start it up it barely stays running. but then sometimes it doesnt even start. when i drive it it studders really bad like its not getting enough fuel or something. i put a new fuel pump in it and changed the filter and its still doing it. it sometimes stauls top if i just let it idle. what do you think it could be. the ecu isnt trowing any codes at all either.

 

I've had 88-91's at my shop have main relays start to fail and cause a similar problem.

 

i had p brand new one from honda put in about a yera and a half ago. do they go out that quickly? do u think it could be the ecu itself?

 

have you altered the timing at all, maybe replaced a intake maifold gasket and have a bad leak, or did anyone replace the timing belt and maybe not get it back to spec????

 

maybe a dead cylinder? Do a compression test, check you plugs etc..

 

it only does it after you run it for about 10 mins. its not the main relay cause i just tried my brothers on mine and it still did it. the ecu isnt throwing any codes? i just put on msd ignition but it started to run like this after i ran at the track. i had msd a month before that!

 

Go over all the wires in your ignition system, I know how on the Msd ignition systems that you have to cut the stock connectors off. Try soldering them if they're not already. It sounds to me like an ignition problem. Good luck -Ben

 

Get the right plug wires and check your connections sounds like a combustion problem for sure. I would start by checking my plugs see if your running rich or lean. Would help to figure out if its spark or fuel then go from there.