Am having a real problem with that first start in the morning. Have a 88 E150 w/302 EFI. Every morning for the past week it hasent started. But after cranking on and off for an hour or 2 it will finally fire up and then run great. Once it starts that first time will run all day. Shut it off and it fires rite back up. Its just that first time getting it started. First replaced the TFI module, no help. Then removed and tested the TPS with an ohmeter. It tested OK. Cleaned the throttle body and put it(TPS) back, no help. Then began to suspect a fuel problem. I pulled a plug the next morning after some initial cranking and it was dry, no fuel. But theres fuel in the rails and its under pressure and once it finally fires I can relieve all the pressure at the fuel bleeder valve and it will still fire rite back up. Also while cranking for that first start theres a definate fuel oder but no black smoke when it finally does fire and like I said no fuel on the plugs. The external pump is coming on for about 2 seconds every time I turn the key on. Theres spark to all the plugs but is yellowish not blue. Did an ohmeter test on the coil and it tested OK for resistance. Can the coil still be bad? Whatever it is it eventually goes away will a lot of cranking until the next morning then its the same thing all over again. Theres little temperature change between day and nite here mayve 5 or 10 degrees. Would appreciate any help, advise, suggestions. Thanks.

 

There are several ohm meter tests for the coil (primary, secondar, primary to ground, all these when coil is cold and again when coil is hot, a flashing light test is sometimes used in coil tests too--see the manual, either Chilton or Haynes) as well as a spark test (you can buy a spark tester for 10-15 $ at some parts stores (don't know how good they are). Yellowish spark seems bad, but I thought that was from the coil wire not spark plug wire.

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Replaced the coil this morning and also did new cap, rotor and plug wires. All for about $50. It seemed to help. The real test will be tomorrow morning thats when it fails to start. Hope this solves it have other things to do. What was/is hard to figure was that after cranking for an hour or so in the morning it would suddenly fire up and run great immediately. No smoke, and smooth, quiet, strong, ect. And then the next morning the whole problem would start all over again. Did both the primary and secondary resistense tests on the coil when it was cold and it was rite up to specs. Also have spark tester and all plugs tested good though it was kinda week. Anyway since I wasent getting anywhere I decided to go ahead and replace the coil, cap, rotor & wires it needed done anyway. Will see what happens tomorrow morning. Thanks for the help will reply with results.

 

Truck started this morning though not as quick as it use to. Cranked for about 3 or 4 seconds before firing but thats a lot better than cranking for an hour or 2. So the coil apparently was the main culprit. The old coil stilll tests rite up to specs on the ohms resistance test?? Will check the timing and call it a wrap. I never did that after I had the distributer out. For having nearly 200K miles on it I guess its as good as its gonna get without doin some serious wokr on it. Later

 

Well that is pretty good news. I wonder if the parts store has a coil tester? If so see if they will test it. I think their tester may do different tests that could show its weakness. Regardless, now that you only take 2-3 seconds to start you can visit the "Hard Starting" thread at https://www.ford-trucks.com/dcforum/DCForumID39/5508.html where I am trying to figure out my minor problem of 2 second starts.

 

One problem with your coil that a tester will not pick up is and small cracks or damage done to the coil case that will cause the coil to ground out or Condensation to enter and change the value of the coil.

 

I also wonder if the internal structure could break down causing some of the windings in the primary circuit to contact each other, effectively reducing the number of windings and the output, but still showing good resistance on the ohm meter test. This would fit with your weak spark. I bet the old coil was not putting out the full voltage, but maybe only 60 or 70 percent of it.

 

Your probably rite about the coil it was not up to par even thopugh the ohms resistance test was OK. When this whole thing started my first instinct was to replace the coil. Instead I tested it and moved on. Then replaced the TFI module pulled, tested & cleaned the TPS & IAC, ect, ect, began suspecting a fuel problem, ect. Should have gone with my instincts. Lesson is dont overlook the basics. Thanks for the input.