CA18DE question

[McAdam]

hello all, I have a pulsar SE with the CA18DE motor in it. I figure you guys can help me out. The damn thing used to run like a raped ape, but now it seems as though its firing on only 3 cylinders, runs really rough. I have changed the plugs, and they are fine, yet it refuses to run on all four. My freind had a pulsar that did this after some time and I had a 1987 with the ca16DE that met the same fate, although it also blew a head gasket. This problem just started recently on a long road trip. but up until then, it ran fine, what gives? sensor? vaccuum hose? computer?? I am at my wits end!

McAdam

[themadscientist]

which cylinder is bad? does it pass a compression check? even across the cylinders? the A-spec DEs use plug wires right? confirm the dead cylinder is getting spark, it has new plugs but are they getting juice?

[pulsar gtr]

It is either your coil or your power transistor modules, I don't know about you guys, but I've owned 3 pulsars and I usually replace one module per car per year;;go figure.

As themadscientist said , check if you are getting a spark on the spark that you suspect is not firing, if it is not firing, swap the coil with a working one, if it is still miss firing, it is definitely your power transistor module. It is located on the top right hand side of the engine, above the transmission, it is square in size and it has an aluminum heat sink type of shape.It is bolted on with 4 8mm long screws

Good luck,

PULAR GTR

[McAdam]

yeah, problem is I dont think its ignition related. When I pulled the plugs, all looked O.K., as in none of them were wet. would a clogged fuel filter possibly cause this? the problem comes and goes, so I dont think its anything major. any other ideas? thanks for the ignition ideas thats what I thought at first as well.

best regards, McAdam

[S15_silvia]

did you check for spark? and did you check your wires?

[boost_boy]

Did you check the codes on the ECU?