just got 91 explorer and it has a starting problem

[batshiz]

need some advice, put a new batery in our 91explorer 4x4 and it turns over fine but gets sparatic spark what could cause this!! but it pull starts fine! any ideas!!!!!

[batshiz]

thanks for any help and ideas greatly appriciated!!

[Opera House]

How have you determined the spark is erratic? Is it erratic when it runs or just hard starting. This has a DIS ignition system that places two spark plugs in series. Any ingnition hardware problems are magnified. I'd start with new plugs. Lower intake manifold keaks can caus plug problems in less than 4K on new plugs.

[batshiz]

took spark plug out and put it up to the groung and it takes like five seconds of cranking before the spark will hit then it goes away for like two seconds then it will start! What would you do to fix problem got ford code reader for eec and mcu but no trouble codes come up for the motor! changed out coil pack ,starter,edis module ignition module!

[Opera House]

You have to be careful that only one spark plug is removed when you do this test. That said, it could be a problem with resistance in the EEC relay that powers the computer, Ignition module behind the pass headlight and the crank sensor. I would go for a weak crank sensor located on the front of the engine. This has a once per rev spline spacing difference so the computer knows where it is. This might explain the long period between sparking. You could unplug the connector on it and reinsert it to clean possible corrosion. Some have reported that light tapping on it sometimes makes it work in an emergency.

[batshiz]

t/y operah house! but we have two explorers and the manual for it and we changed out the sensor but haven't checked the resistance on the relay but will and then let you know t/y again!!!!!!!!