97 explorer 4.0 no spark

[Tastlikechikn]

Hey guys I need some input again As I said 97 4.0 ran fine when parked day before yesterday, now it has no spark. Checked all the fuses and relays I could find and tried a new coil pack but still no spark. Any help would be appreciated. Thanks

 

[97RedXLT]

Is there any codes stored?

 

[Tastlikechikn]

Don't know Red.My son called me last night from college and said it wouldn't start and I drove 70 miles with a handful of tools hoping for a fuel pump relay or a bad fuse. I found that it had fuel and no spark and I couldn't even remember how to check the codes. I think I'm gonna grab a dolly and go drag in. Somebody suggested crank sensor around$16 I might throw that it. but not really up on this stuff I'm still more comfy working on my 68 Torino and my 62 Chevy P.U. How do I check those codes?On/Off x3? then count flashes? Thanks

 

[swetrid]

You can try just unplugging and then rerinstalling the crankshaft position sensor. If it starts clean and ck the wiring at the sensor.

 

[Tastlikechikn]

Thanks swetrid I'll try that before I remove the old one. I probably won't have time to go get it (or check anything) until Tue. Is there a particular fuse or relay inside (under,hood,dash or kickpanel) that I should be looking for? One little "snag" I hit was that in the fuse/relay box under the hood said "refer to owners manual" to I.D. The truck is 97 but the owners manual in the glovebox was for a 99. They are not the same so I was flying blind, plus I have now found out (by looking at 2 97s side by side in a salvage yard one w/o motor) that I probably have a couple more relay boxes to check.
I really need a 97 fuse/relay, I.D./Location chart??? Any Ideas? Thanks
OK I found fuse/relay info at www.motorcraftservice.com

 

[Tastlikechikn]

swetrid you nailed it! I just unplugged CPS put some corrosion block on it plugged it back up and drove it 70 miles to the house. Thanks for the help everyone.

 

[imp]

swetrid you nailed it! I just unplugged CPS put some corrosion block on it plugged it back up and drove it 70 miles to the house. Thanks for the help everyone.

You learned of one of the very few computer inputs which can cause a "dead in the water" condition.

Crankshaft Position is vital to knowing WHEN to produce the spark. In EFI early-on, Ford achieved this via the standard ignition distributor shaft rotating a toothed "cage" which produced an electrical "blip" for each cylinder. One "tooth" was narrower than all the others; it related to cylinder #1, which then allowed computer to follow the others in the proper order (firing-order!). The "signal" was generated within a "Thin-Film" module ("TFI") which was attached directly to the distributor bowl. Experience showed the location was "too hot", and on 5.0L HO engines (and some others, 4.9L, etc.), around 1994 or so, the module was moved to a "heat sink" mounted remotely, on the fender apron. By then, it was obvious that a "toothed-wheel" mounted expernally on the crankshaft somewhere (front vibration damper was a good place), would eliminate lots of problems, and was less expensive to produce. Just a few of my useless thoughts.......imp

 

[swetrid]

swetrid you nailed it! I just unplugged CPS put some corrosion block on it plugged it back up and drove it 70 miles to the house. Thanks for the help everyone.

Glad I could help you out!