hondacivic121

my 91 civic hatch back fires when it gets to 5 rpm and i replaced the dizzy checked the timing new wires and spark plugs what else could it be

VeeL_B20

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondacivic121 &raquo;</TD></TR><TR><TD CLASS="quote">my 91 civic hatch back fires when it gets to 5 rpm and i replaced the dizzy checked the timing new wires and spark plugs what else could it be</TD></TR></TABLE>

I've had that happen to me a couple of times. Do you have a fuel pressure regulator? The most common problem with backfiring is too much fuel gets into the motor and not all of it is burned, the fuel then leaks to the exhaust and BOOM it detonates in the exhaust pipes. If you have a FPR, try lowering the psi, but not too much otherwise you have absolutely no power. lol. GOOD LUCK!!!

hondacivic121

nah i dont got a FPR but i did the ECU codes and my ECU is giving me code 74 which is cylinder 4 misfire....so i think it might be a bad fuel injector or cam shaft, i got 3 new injectors today and ima put them on tomorrow and see what happens and it it still does it ill throw a new head on it and hope it works

Darrell Bs 10SecEG

If its not your injectors,Try another ecu out and change your spark plugs cause one might be fouled and cant spark to ignite the fuel.That happened to me awhile ago.Good Luck

hondacivic121

ive tried a different ECU and my plugs and wires are new i changed them when it started to do this

Darrell Bs 10SecEG

Try changing the Fuel pressure regulator on your fuel rail and see what happens.Also pull out your injectors and see if any of them might be cracked and throwing in extra fuel in the cylinders bro.

hondacivic121

wheres the fuel pressure regulator located at