Car dies, then cranks with no spark.
Hi guys, tagging on as a new member.
After doing a lot of reading through these threads, it's obvious that a lot of people have the same issues with these Ford ignitions. However, it doesn't seem like I'm finding the right solution. I've been through the No Spark tests, but not sure about the results.
The problem started a couple weeks ago, when I replaced my Motorcraft (original DY1074) TFI module, due to a problem with bad spark at high RPM. The new Motorcraft DY1284 module (supercedes the DY1074 from what I understand) made the car feel very strong to 6k RPM. I thought the problem was fixed, and all was good. However, 2 days later, my mustang left me stranded on the highway, and wouldn't restart. I had it towed home, and after some research, decided I had another bad TFI.
I replaced the TFI module, and also bought a rebuilt Motorcraft distributor (in case the PIP sensor was the problem).
This new TFI and distributor ran great, for about an hour. Then died again. I could restart and run for a moment at a time, and was able to limp the mile back home.
Rather than throwing more parts at it, I have been running diagnostic tests (Voltage checks, LED test light), and keep coming up with the same test results. So...I replaced the TFI again, and it died within 30 minutes.
Here's what I've found:
- After the car warms up, it dies like it was turned off with a light switch.
- If I try to restart by leaving the key in the run position after it dies (WITHOUT cycling the key off first), it won't spark at all (verified by timing light on coil wire).
- This seems to be an important part of my ignition problem.
- If I try to restart by turning the key all the way off, and then back on, it starts again (but dies again moments later showing no spark).
- Once the engine cools off, it will run for awhile before it dies again.
Tests:
- I have 12v to both sides of the coil, whether spark or no spark condition.
- When the car is in the 'no spark' mode, I have:
- Battery is fully charged, and never a problem cranking
- 12v power to the ICM
- LED signal flashing from the PIP while cranking, which tells me the PIP is okay
- No LED signal from the ICM to the coil while cranking
- I have 12v ground at the ICM
- Will not start w/spout removed (PIP test)
- When I cycle the ignition key off and then on again, I get the LED signal from the ICM to the coil. Car will start, with or without spout connected (just dies again shortly).
I'm on my 4th TFI module, and my 2nd distributor (all Motorcraft), and even switched out a known working coil. Everything I see is pointing to a bad TFI module, but I'm having trouble believing that all these modules are bad.
I've thought about moving the TFI to another location, but I want to make sure of the problem before spending any more on parts.
Any troubleshooting assistance would be appreciated.
A little about the car:
1992 Notchback, newly rebuilt 5.0
10.5:1 forged pistons, Balanced rotating assembly
Motorsport GT40 X303 aluminum heads, professionally ported
F303 Cam w/1.72 roller rockers
Motorcraft distributor & Coil
3G Alternator w/4GA cable/fuse kit
255LPH Fuel pump, 24 lb/hr injectors
BBK 70MM TB, Pro-M 80mm Mass Air Meter
Cobra 13" front/11.65" rear disks, SN95 Master Cylinder & booster
AJE K member, SN95 A-Arms, 5-lug spindles/axles,
2004 Cobra power steering rack, MM Hybrid steering shaft
Tokiko adjustable struts/shocks
T-5, Cobra clutch, 3:73 gears, Motorsport Aluminum drive shaft
320 RWHP / 333 RWTQ