Turns over but won't start

[clev]

joe, quit confusing the poor guy!!

OK, if you've grounded the STI pin, and did not get a flashing lamp, then you have no trouble codes, = system passes

Yes, this test works on all EFI Festivas, 1990-'93

You stated you do NOT have spark, but DO smell fuel, correct?

If you have a test light, here's an easy check for the next time it fails;

connect the test light clip to battery Negative, and touch the probe to the coil Negative, and have someone crank the engine.

If the test lamp flashes during cranking, then the problem is in the coil itself. If it does not flash, but stays lit all the time, then one of the components responsible for operating the coil is stuck in an 'off' state (module in the distributor, or the one next to the coil). If the test light does not come on at all, that means either the coil has an open circuit, or the power to the coil is absent (comes from ign switch)

Hi FB; I just ran the above checks. To clarify, on my 1990, there are no terminals on the coil; just a plug with a hot and ground wire. I back probed the ground while the plug was still connected to the coil and my wife cranked it. The test light stayed lit; no flashes. Now, how do I get the component to 'unstick'? Also, I have swapped out the module and it makes no difference. Is there some way to test the distributor module? There is a small, square, 2-wired ???resistor??? mounted beside the coil with the same colored wires as the coil and it is hot when the key is on. Can/does that effect coil operation?

Still fishing; I appreciate your help.

[clev]

Hello again, FB; I just re-read the test procedures: if the lamp flashes, I have a problem; if it doesn't flash and stays lit I have a problem; if the lamp does not come on, I have a problem. HMMMMM? What happens if everything works correctly and there is no problem???

[FB71]

ok, I've got the flu, and NyQuil has been clouding my thought s a bit. Soory if some of my statements don't make sense.

Yes, you have a plastic 2-pin connector at the coil. Each one of those pins ends in a terminal... tech speak... sorry. The blk/wht wire should have 12v when the key is on. The yel/grn wire should cause the test lamp to flash when crankoing or running. If it flashes, but you still have no spark, then the coil itself is most likely at fault. If it does not flash, but stays lit, the coil is being held in saturation, either by the ignition module, the distributor or the pcm. the ign module is the small box near the coil with three wires, yel/grn (coil control), blu/org (signal from pcm) and blk (ground). To check the input to the module, you'll need either a digital volt/ohm meter or an oscilliscope. The DVOM doesn't need to be an expensive one. The quick and dirty check is to set the meter to DC volts and probe the blu/org wire cranking. you should see some small voltage, and it should bounce around. DO NOT USE AN ANALOG (NEEDLE TYPE) METER!!! THIS WILL DAMAGE THE PCM. If you get a fluctuating voltage on the bl/or wire, then the module is most likely at fault. If you see no voltage,or a steady voltage, that means the PCM is not getting the correct signal from the distributor. The dizzy (distributor) has three wires; blk (ground), yel/blk (power from the main relay) and yel/blu (signal to the pcm). Make sure the ground is secure and clean, verify 12v on the yel/blk with the key on, and use the DVOM or scope to check for a small, fluctuating DC voltage on the yel/blu during cranking. If the there is no voltage, or constant voltage on the yel/blu during cranking, you need a dizzy.

[jglutz]

Jim...just curious...dosn't the dizzy pick up go thru the ECU....so the problem could be between the dizzy and the coil. Also, on the market today are needle meters with very high input impedance..they respond quicker than DVOM's..and yes they don't have the versitility but some app's just require them...And scopes...most of the digital's on the market today. As an instructer...check out Virtual Bench by National Instruments. Turns any PC into a scope, DAQ, signal genny, and lots more..16 channels min; +/-400$. Will create a post after my drink runs dry or dinner gets delivered.

[FB71]

Joe, yes, taht's what my post describes. The dizzy provides an input to the pcm, the pcm provides an output to the ign module. I know Simpson has a high impedance analog, but I'm not expecting your average DIY'r to have one. I've seen Virtual Bench, our Electronics Dept uses it, very nice. In Auto/Diesel, we use Fluke 97 scope/meters.

As for analog vs digital, I always tell my student to invest in an inexpensive analog meter for tracking intermittent open circuits in wiring harnesses. Nothing better. Learned that from tagging along with my dad, servicing alarm systems in the 70's and early 80's. Ahh, current-sensing relays and dry cells....

[jglutz]

^^ No disagreement...some day if you have the time hang the probe from the Fluke 97 on the +12VDC to the radio while it's on....students will realize just because it digital doesn't mean its better. V'Bench..have at home...use it to record the profiles of cold and warm engines at idel and high RPM....if they mis-behave...i record the profile and compare to previous.

[clev]

Error. I missed your previous reply; sorry.

[FB71]

:laughing3:

I've been doing that for years! The old Ford WDS scan tool has a scope function. I built myself a library of known-good patterns. When a customer would come in with, let's say, a noisy fuel pump, I'd scope it's pattern, then print both it and a good pattern. Present both to the customer, and let them make the descision as to wether or not to replace the pump at this time, or wait for it to just outright fail. I liked to give my customers as much info as possible, and help them make an educated choice. Not to mention all the times those good paterns helped me ID 'mystery' problems...