Jerkin, service engine light comes on, dieing

which engine? (asked now 1000 times, only 2 ever answered)

tune up time, spark parts, rotor to plugs. filters. both.

its called a 60k mile tune up solves most.

my guess, is its misfiring or

is this the ASD relay dropping out then back in, as driven.

jerked before and after CKP sensor, did you know its the last thing to fail......

see the list of ASD drops.

misfiring, can be felt, its like a misfiring chain saw, ever here a 2 stoke misfire, ratta, tata ,tat?

some call it jerking, its not, is misfiring. (3reasons ) and 25 causes.

but jerkin real, like if you cut the ignition that is and instant bog.

but if you off the key and back on , fast, that be a jerk

that is total power loss. not misfire. its loss spark and fuel.

and jerks hard.

so does loss of 12vdc to the EFI system.

so the first step is to see if its the ASD relay dropping out.

on all jeeps.. 93 to now.



ASD



http://www.fixkick.com/Jeeps/ASD.html



automatic, shut down. (relay and EFI logic)



key point, the ASD will kill the engine, if fit sees spark is bad.

so its a chicken and egg deal.

here is the logic.

key on , crank , ASD closes, fuel injects and engine starts

then dies in seconds. or runs full time.

note that if the ECU sees spark dead, it cuts spark.

Sounds odd , huh. but is NOT.

this relay stops all car fires. (caused by this protection not in place)

Sounds like a basic cylinder miss-fire. Common issues are spark plugs, wires, coil, and fuel injectors,
is the check engine light on when the engine is running ?

what car? year? engine size? what is the code?

i have a pontic sunfire 2003 and check engin light is on all the time

If your losing compression then I suggest doing a compression test and then following it up with a wet compression test to determine whether the problem is in the valves or pistons.
Wow one tune up in 122k miles jerking not really an ignition thing more like a fuel thing. If Compression test results are good then do a full tune up even replace coil packs or distributor ( which ever is applicable) and replace fuel filter.
These vehicles are not known for major engine problems (blown engines bad valves etc).
Big with transmission problems if its a 6 cylinder not the 4 cylinders.

Have engine wiring harness checked as 1993-1995 MB's were forced by US to use biodegradanle insulation on its wires. If thats not it replace coils and do a tunes up.

What about fuel filter or fuel pump?
Sounds like it is not getting the fuel through or is getting to much fuel
Check choke not sticking and air filter clean etc.
Regards Craig

im lookin forward to jerkin we i approach old age too-about time for a mech chec up huh-the engine lite probly indicates for new O2 sensors or the transmission sensors-$$$-hav car scanned for free at ur friendly discount place-befor u run the marathon

check transmission oil level,or even try changing oil and filter

Sounds like a range sensor problem! It mite be bad and need changed! About $80 for the part, versus $180 for ford to put it on!