TFI shielding.

[SLow5.0]

Hey guys wanted to get some opinions on an issue I'm dealing with. Roughly 2 years ago I replaced the TFI module plug, cause it broke apart. Spliced in the new plug from Blue Oval industries, and did fine. Last summer, I was having an occasional cutout that lasted half a second, and would happened just randomly. Feels like the engine just tuned off and on very quickly.
This got worse later on and parts had to be replaced.
Fast forward to now about a month ago, after replacing a distributor, ECU, module and coil. The half a second cut out is happening again. Noticed yesterday, it happens when I punch it. But goes away when I back off. I've done some research on this trying to something that will help and one thing crossed my path was the RF shielding that is on PIP, SPOUT, and neg, going to the TFI module. I never replaced the wire looping around those wires, and the foil. I spliced in a copper wire to the existing wire and wrapped it around those, close to the Module plug and wrapped it back up with tin foil.

It helped some, but still randomly with the quick cut out. I'm able to punch it and once at a high enough rpm like 4K in 5th. I'll get a single blip. I think I'm on the right path, but need to correct this. I've code scanned the car, KOEO got me a 15, 96, and 11. Not worried about the 15, since that is due to the Moates QH chip in the ECU port. KOER, got me a 20 cause my idle is a little high. The parts that were replaced as stated above were bad. ECU had two leaking capacitors with one broken connection, the distributor had a broken plastic connection connection inside, and the old MSD TFI coil finally bit the dust. I have checked my grounds, they are tight and clean.

Is there anything else to check before I start breaking out the volt meter?




Sent from my iPhone using Tapatalk

[JACook]

Make sure that the TFI shielding is not grounded anywhere but at the ECU ground. Unspecified grounds
on a shield can create ground loops that can induce noise into the wires that the shield is supposed to be
shielding.

That said, the first thing I would do is inspect the ignition switch - Make sure it's not separating.

I'm curious about the 'This got worse later on and parts had to be replaced' comment. What parts had to be
replaced? And what, specifically, were those parts replaced with? I'm presuming that this cured the problem
with the engine cutting out?

I'm also curious about the replaced distributor, ECU, module, and coil. had the cutting out started happening
again before you replaced these? Or it started happening after? And what, specifically, were these replaced
with?

It would also be useful to know what the tach is doing when the engine cuts out.

[erratic50]

Fusible links age and go bad - monitor current through the links. If if wildly fluctuates it suggests a problem. I'd replace with blowandglow fuses and waterproof fuse holders. Solder and shrink tube them in.

Consider replacing the ground strap or adding a hard wire ground between your block at the negative lead attachment point and your k member. The factory grounding strap between the body and the head goes bad. This creates a weird ground loop between the ECU grounds and the ECU case ground. And boom - motor cuts out momentarily. Engine shakes, ground is restored - for now.

Ask me how I know......

BTW - I would also cut out the factory 4 grounds to one splice connector that grounds to the fender. It may pass visual inspection and even ohm tests - ours did - but the moment current was there the amperage was all over the place. They fill with moisture then corrode in ways you don't see. Ground it to the battery.

We were blowing the fusible link then fuses. Started blowing fuses at the ECU relay once we added one in there. But that's not the only way this problem manifests. I'm pretty sure the 1 F stiffening cap compensating for the bad ground is the reason we were popping fuses or links looking back.

[SLow5.0]

Make sure that the TFI shielding is not grounded anywhere but at the ECU ground. Unspecified grounds
on a shield can create ground loops that can induce noise into the wires that the shield is supposed to be
shielding.

That said, the first thing I would do is inspect the ignition switch - Make sure it's not separating.

I'm curious about the 'This got worse later on and parts had to be replaced' comment. What parts had to be
replaced? And what, specifically, were those parts replaced with? I'm presuming that this cured the problem
with the engine cutting out?

I'm also curious about the replaced distributor, ECU, module, and coil. had the cutting out started happening
again before you replaced these? Or it started happening after? And what, specifically, were these replaced
with?

It would also be useful to know what the tach is doing when the engine cuts out.

Ok the parts that were replaced was the ECU, two outta the three capacitors were leaking with one of the leaking caps broke a lead, the distributor got replaced ( reman) due to a piece of the Hall effect switch broke off. Replace the module( motorcraft ), the peritronix one the metal back came off.

The car acts like it is cutting out like a blip. When this happens, the tach bounces with the blip like a shut off, down to zero.

Since then I have done some more work, I have ohm'd the wires from the ECU to the module, everything comes back good, nothing grounded. I checked voltage as well and that has came back good. I started looking at the ignition switch. Low and behold, the switch is starting to separate( plastic from the aluminum mount. I replaced that. So far I don't have the cutting out. I ran another code scan KOEO and have only 96 and 11, KOER gives me a 11.

One issue hopefully is gone, to fix this.

BTW in case I fine something else do know where I can find replacement fusible links?


Sent from my iPhone using Tapatalk

[qikgts]

BTW in case I fine something else do know where I can find replacement fusible links?

I've found them at NAPA before.

Good info and fusible links are available for purchase at the link below too.

http://www.madelectrical.com/catalog/fusible-link.shtml

[Haystack]

Sounds like ya got it licked hopefully.

One trick i use when looking for bad connections/shorts with a digital meter, test all the positive leads against ground in the smallest voltage scale avaliable. Usually it shows up better in ohms, but its really quick and easy if ya got all the positives and negetives mapped out.

[gr79]

Hay thanks. May try the switch replace.

My 93 Ranger 2.3 DIS dual plug does has been doing that for years.
Started with the tach blip.
Escalated to multiple blips and afterfire (blows out regular muffler baffles but not a straight thru cherrybomb).

Runs fine when tach works until tach starts twitching.
When the tach works, i know its a matter of miles before engine timing will act up.
If a work day, i take the car.

i learned to pull over and let it go thru its fits for 5-10 minutes.
Cannot drive it when it bucks so bad.

No way am i driving on the eway until tach zeros and stays dead.
Usually between 40-50 degrees out, cold start after sitting over nite.
The crappy weather days i do not want to drive the Mustang.

Once tach drops to zero, all is well the rest of the day, including after work startup.
Rarely does the tach work again until ???.

Also found out the HVAC blower fan speed affects the ign timing when tach is acting up. WTF?

When ign starts acting up, i switch back and forth from high to low blower speed.
Kind of like switching from A to B ign module like in a race car.
This usually works while driving until the timing settles down and tach reads zero.
Can confidently be started and driven normally rest of day.
Sometimes need multiple start trys until the PCM comes up with a default? timing strategy.

Kind of a consistent malfunction pattern. No solution on the internet.

Drove it to work today. Temp 50+. Zero rpm on tach from first start, no blips. Ran fine.

Figure its the CK sensor assy and maybe something else like a temp sensor.
The CK sensor wire had a abrasion wear spot which i temp fixed a long time ago.
Any ambient temp lower than 40 or higher than 50, tach is zero and truck drives fine.

Any loose fuel pump, PCM, relay or fuses will also cause havoc.

so i go on
until i let the dealer at it and my wallet.
the 3 digit OBD I code i get is too vague to pinpoint anything.

[SLow5.0]

Hay thanks. May try the switch replace.

My 93 Ranger 2.3 DIS dual plug does has been doing that for years.
Started with the tach blip.
Escalated to multiple blips and afterfire (blows out regular muffler baffles but not a straight thru cherrybomb).

Runs fine when tach works until tach starts twitching.
When the tach works, i know its a matter of miles before engine timing will act up.
If a work day, i take the car.

i learned to pull over and let it go thru its fits for 5-10 minutes.
Cannot drive it when it bucks so bad.

No way am i driving on the eway until tach zeros and stays dead.
Usually between 40-50 degrees out, cold start after sitting over nite.
The crappy weather days i do not want to drive the Mustang.

Once tach drops to zero, all is well the rest of the day, including after work startup.
Rarely does the tach work again until ???.

Also found out the HVAC blower fan speed affects the ign timing when tach is acting up. WTF?

When ign starts acting up, i switch back and forth from high to low blower speed.
Kind of like switching from A to B ign module like in a race car.
This usually works while driving until the timing settles down and tach reads zero.
Can confidently be started and driven normally rest of day.
Sometimes need multiple start trys until the PCM comes up with a default? timing strategy.

Kind of a consistent malfunction pattern. No solution on the internet.

Drove it to work today. Temp 50+. Zero rpm on tach from first start, no blips. Ran fine.

Figure its the CK sensor assy and maybe something else like a temp sensor.
The CK sensor wire had a abrasion wear spot which i temp fixed a long time ago.
Any ambient temp lower than 40 or higher than 50, tach is zero and truck drives fine.

Any loose fuel pump, PCM, relay or fuses will also cause havoc.

so i go on
until i let the dealer at it and my wallet.
the 3 digit OBD I code i get is too vague to pinpoint anything.

I'd check your ignition wiring. Ohm check first for any breaks then voltage check. What codes did you get from the scan?


Sent from my iPhone using Tapatalk

[Haystack]

X2.

My 88xr7 tach didnt work at all. Would move a bit close to redline. Ended up being a spark plug boot. New wires and it works good and idles good again.

[erratic50]

I've burned off the coil wire multiple times on mine.

I am a fan of waterproof fuse holders and blow n glow fuses and shrink tubes and solder rather than fusible links. Link material decays over time, fuse setups are a long term fix.

Double check your relays. The ECU relay just hangs there a lot of times so if some bone head did a bad antenna swap where they didn't do the drip loop rightvand didn't seal it up the ECU takes a bath and the relay can fill up with water. (Ask me how I know - F)

[gr79]

no intent to hijack thread. food for thought info only
New Motorcraft wires for the Ranger now on the to-do list.
Cant hurt. Nor can new coil packs and plugs. icm fine and double grounded.
the screws were a real treat to remove. Now have ss hex there.
all relays seated and tight

dealer gets the honors on plugs. although Motorcraft platinum, they snap easily.
the long life plugs that like to seize in head

Code is 224. a common one.
i suspect secondary coil pack and or connectors
possible failing temp sensor connector. need to check further
temp related problem does not rule out air temp sensor in air box but no code.
other forums have different solutions for 224
wires, plugs, coil packs icm
CEL light is always on when tach is dead, off when tach works

This Mustang did have a problem with the dist sensor pickup wires back in the 80's
they fatigue where they exit the housing
prob from the advance plate movement or bad design
causes intermittent engine cut out
new cardone reman dist installed in 2000 no problems to date
prior fix was new Motorcraft pickup assy. Have new spare collecting dust but thats ok.