1989 240sx sputters and bogs

[lumpy racer]

ok i am having a couple problems. i race a 1989 240sx at a local track by my house. it was about 3 weeks ago i sent my computer out and had a jet chip put in it. that week the car started to spit and sputter on the straightaway. it was the timming. i did a compretion test and it was down in the 4th cyl. so i sent the head out and put new rings and bearings in it. we put it all back together and this week it had no power and it was really spitting and sputtering down the straight away. it was not timming because we checked it. and i even put a stock ecu back in it.another thing is that everything is gutted and there is no extra wires or vacum hoses that don't need to be there or so i hope. i put new plugs in the car and ran it for a while and they look brand new there not even tan. this only happens under load on the gas it won't do it out of gear.

can anyone help??

[lazersgm]

is it doing it under partial or wot?

[180fan]

putting the title of "help??????" won't do anyone any good. I usually will pass those up and let them go away until the poster gets a clue as to how to get some help in a more meaningful way.

so did you check over the tps and mafs connections?

[ricebike]

after those connections are thouroughly checked, along w/ other things ie vaccuum various sensors & what-not...

i'd get some1 w/ a similar ECU & swap it temporarily to see if things clear up. mebbe jet had miscalibrated your ecu...

[lumpy racer]

thanx for the help on the title. i don't have the ecu that was done by jet chips in the car i have an ecu from a 1990 in it ..... are they diff.??????? it is under load at wot. when it does it and it will do it as soon as i step on the gas.

does anybody have a diagram of the vacum hoses and sensors that are needed. it's not street legalm so i don't need any egr or anything. just the ones that make the car run and go fast. i think i may have taken one off that needed to be there.

[nuts510]

I have ran into problems like that being the ignition Coil also I have seen the igniters calls strange running, have you checked for codes? have you checked the fuel pressure? What's the ignition timing at as it help if you advance it? Good luck

[240sxbobbis]

i had that same problem with my car about one week ago acutually one of my spark plug cables had a crak in it and with all the rain in maryland water got into it and it would sputter and the idle would drop and it would sound like i had a v8 in it so check your wires and see how they are change them and try it if that doesnt work return it but thats what i did....