lsvtec_teg

i have a b18c1 motor in a 94 civic. scotts machine shop bored the motor 25over and put brand new itr pistons in and the head is milled because the head gasket blew before scotts machine shop. the motor is now in the car. when we crank it, it back fires and spuders, and the sparkplugs are wet with gas. the timing is right and we replaced the distributor, new plug wires, replaced injectors, changed map sensor. allso its runing a skunk2 intake manafold insted of a gsr one, with a p30 ecu. the ecu is only throwing a o2 sensor code, compression test says 125 on all cylnders........... please helpppppppp!

lsvtec_teg

bump

MaxSterling

compression is consistent for all four which is good, but kinda low. I would expect itr pistons to increase compression for gsr engine and be in the neighborhood of 230psi for a healthy engine. back fireing is a sign of too rich fuel mixture or fuel not being ignited. check if you have the spark wires in the correct firing order on the distributer. make use you wired and plugged in o2 sensor...o2 sensor CEL will make the car go into limp mode and could be the cause of running rich.

2lua

compression way too low. recheck for timing, plug wires for firing order.

eg6h8k

omg 120? thats way to low for that motor...it should be between 220-250..i know its a new motor so the rings are prob not seal yet..but still thats way too low..are u sure the spark plugs wires are in the right place on the cap..cuase once i place the wires wrong on the cap..it backfire real loud and sputters like crazy..

lsvtec_teg

help the timming is all right the car sparks the plugs are right and i have no idea what else

degooser

125 psi is really low...throw some oil in the cylinders and see if it fires...

owen_the_soyboy

have a fresh pair of eyes check the timing, it may be WAY off

lsvtec_teg

125 psi is only on the first key revolution then after that it is 235psi the timming is right the only way how you can mess it up if you [are] blind or you are setting it in the dark

rocco

Isnt your bore too big for itr pistons,i figured itr pistons and gsr pistons noth had the same bore

King Tut33

You can get .25 overbore ITR pistons. The compression sounds fine to me. It sounds like a fuel issue. What injectors are you using? Also if you are getting a bad O2 sensor code then your car doesn't know how much fuel to put in, so that is probably also part of the issue. Replace the bad O2 sensor and make sure you have no vaccum leaks from the intake manifold.

ek_type_r99

o2 sensor must be the problem, it might be reading a higher oxygen level(than what it is) so the ecu is putting in more fuel to balance out the reading

also remember that a p30 ecu is for a 1.6L not 1.8L but that shouldn't make a difference

lsvtec_teg

yeah guys i have no clue i just dont think that the 02 sensor will throw it off that much i have ran cars gefore with a 02 code and they will run fine.