[carlstadt]

I took my 94 Jimmy 4.3l cpi to 2 different shops, it surges or lopes and stalls at idle, it also stalled on the road about 45 mph and would not start (had to have it towed). Now it starts but runs bad sounds like it's missing. One mech. changed the iac (no help) he said it might be the eng. harness or the ecm but he is not sure. The other mech. (diff. shop) said it has a rod knock and there is a knock sensor that retards the timing and this might be the trouble. He said the rod knock means I need a new eng. Anyone have any ideas, how do I check the ECM and the harness, anyone know someone in Bergen county N.J. that might be able to help.Sorry for the long post. Thanks BILL

 

[meeh350]

pull a spark plug, if its all fouled out you probably have a injection problem... they have a tendency to leak and or the fuel pressure regulator goes bad... i doubt its the knock sensor retarding the ignition to that point... Ive seen some engines knock pretty good and still run fine even with active knock sensors............. however unthread it from the block and run the motor with it out.... if the problem is fine then you know the knock is causing the knock sensor to go crazy..... if the knock is that bad then there is a possibility that your engine wont last long... ive heard knocking engines go for years if maintained but it might be too late for yours...........like i said though... .if the plugs are fouled out then its probably injection.... going to have to fix what ever is wrong with the injectin system and put new plugs/wire/cap/rotor and probably a new 02 sensor

 

[carlstadt]

Knock sensor

Where is the knock sensor located, and if I take it out should I plug the hole or cap the sensor? Can I just unplug it? Thanks Bill

 

[burb_n_coach]

looking at www.autozone.com under component location.. it could be
UNDER HOOD, DRIVER SIDE, LOWER ENGINE AREA, BELOW EXHAUST MANIFOLD, MOUNTED IN ENGINE BLOCK
or
UNDER HOOD, PASSENGER SIDE, REAR ENGINE AREA, BELOW INTAKE MANIFOLD AIR BANK, MOUNTED IN ENGINE BLOCK

You can plug it if you want, but on my 89 you don't need to because it dosen't lead to any fluids.

for any component locations, you can look them up at www.autozone.com
look up part under shopping and once you find the part click on part location.

 

[BlazerLT]

I think your CPI unit bit the dust.

 

[FULLTHROTTLE74]

Check your fuel pressure with engine running at idle.Do that and post up what it shows.

 

[rlith]

Check the fuel pressure, fuel filter, CPI and nut kit I'm leaning towards the cpi or nut kit thogh a bad fuel pump can cause the same symptoms... Check you pressure at the shrader valve... It should be 56-60 to start it, and 61-65 at running