Won't run

[dgriff1]

have 89 wrangler 2.5 with tbi thought ihad fuel pump problems would run fine for a while then wouldn't start, then would start. Took it to be smoged ofcourse it ran great passed no prob. now nothing no spark I only have hayes repair book but they don't have much eletrical info,replaced ing coil because of the no spark issue. I'am old school check points ect. but this is A computer car seamsto have a relay on bottom of fuse box that says ing. don't know what tells coil to fire any help would be apprecated thanks Dave

[yjdave]

CPS.."crank position sensor" on the bellhousing and controls spark/timing.

	Crank position sensor A crank sensor is a component used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a timing mark on the engine.

[dgriff1]

thanks for info noticed theres no wires coming out or in to distributor

[dgriff1]

Thanks yj Dave,seems to run ok now tapped on old cps before I removed it and it started. Replaced with new one seems to run ok now,hope it stays this way the problem was intermitten some times it would start other times it wouldn't Thanks again

	Crank position sensor A crank sensor is a component used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a timing mark on the engine.

[shvlhd666]

Can a faulty CPS cause intermittent rough idle?

	Crank position sensor A crank sensor is a component used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a timing mark on the engine.

[dgriff1]

I really don't know I just replaced my cps and hoped it would work seems to have. If the thing quits again don't know whats next. I started with the coil that wasn't it but have new coil now! Just hope I don't have to replace the computer , will post how she does Dave

	Crank position sensor A crank sensor is a component used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a timing mark on the engine.

[Bounty__Hunter]

Originally Posted by shvlhd666

Can a faulty CPS cause intermittent rough idle?

That's usually caused by one or a combination of the following:
Bad IAS (idle air sensor)
Bad TPS (throttle position sensor)
Dirty throttle body

	Throttle position sensor A throttle position sensor (TPS) is a sensor used to monitor the position of the throttle in an internal combustion engine. The sensor is usually located on the butterfly spindle so that it can directly monitor the position of the butterfly throttle valve. The sensor is usually a potentiometer and therefore provides a variable resistance dependent upon the position of the butterfly valve (and hence throttle position). The sensor signal is used by the Engine Control Unit (ECU) as an input to its control system. The ignition timing and fuel injection timing (and potentially other parameters) are altered depending upon the position of the throttle, and also depending on the rate of change of that position. For example, in fuel injected engines, in order to avoid stalling, extra fuel may be injected if the throttle is opened rapidly (mimicking the accelerator pump of carburetor systems).