Hard starting

[Black Dog]

I have a 1981 CJ7 I think the motor is 1986. Somtimes it will not start. It cranks and cranks like its not getting fuel or fire. And other times it starts right up. I have changed the fuel pump fuel filter. All tune up parts have been changed. My mechanic has changed the cam sensor I was wondering if any body had any ideas. Could it be in the electronic ignition?

 

[Tommy]

Probably need more information. My '81 has the same problem when it sits more than a week. Once it starts does it run well? The more details you can give us the better.

Tommy

 

[Black Dog]

It does it when it sits and then it does it out of know where., Somtimes its does it once and then its fine. This last week end it did it almost every time I tried to start it it seemed like it would not start and finaly it did. I noticed somtimes the alternator gauge drops like its not charging right before this happens but the battery is always strong.

 

[Torxhead]

A stock AMC 258 i6 / 4.2l six does not have a cam sensor. Could be a lack of fuel problem. More details please.

 

[Black Dog]

The mechanic said he replaced a cam sensor and gave back a used one. This motor is fuel injected if that helps

 

[BusaDave9]

Use a spark tester to see if you are getting a spark.

 

[Torxhead]

So then you must have the Chrysler multi port injection, not quite a stock AMC 258 i6 / 4.2l 6cl. I would keep the used cam sensor, sounds like it is still good. Another possibility would be the crank position sensor. Is the "Check Engine Light" on when it is running? if so then there is a code to be looked at. You should also be able to hear the electric fuel pump come on for a few seconds when you turn the ignition key to the "On" position. Maybe taking it in the a Chrysler dealer if you get desperate, but that is gonna cost.

 

[Sasquach]

They don't have a cam sensor but do have a crank position sensor.

 

[Saddle Tramp]

If it doesn’t die once started (had a crank position sensor issue do that to me once) then I would look at the fuel pump not coming up to pressure when first turned on. Pump could be getting tired and need replacing.

 

[cerrajero]

Fuel injected ??
have you checked your engine code yet to identify ?