Pinging w/90 Lx coupe

Other from the ping how does it run? If in fact it is a ping, and noting it has 147k on it, it is possible you have a carbon deposit on a valve or piston that heats up and pre-ignites the fuel/air charge? What is sea foam? Is that a top engine cleaner? You mentioned it pings when cold? Certainly shouldn't, but you knew that or wouldn't be asking.

There is a thing in these distributors called a ping rod or octane rod that some how affects timing. I can't remember their exact purpose maybe some one will chime in. Anyway is this a replacement distributor? I'm still scratching my head....... With the time light on it what does it read if you crack the throttle off idle a bit? Is your damper new? I've seen the outer ring (has the timing scale) migrate away from its original position thus displaying incorrect timing when shot with the light. Try retarding to 6*btdc without spout just for to see what happens.

What plugs do you have in this?

Try swapping the TFI module for a known good one...

Any codes?

There is no ping or octane rod in a 5.0 Mustang. The TFI module has no effect on timing. If the TFI goes bad, you have a miss or no spark condition.

Dump the codes: codes may be present even if the Check Engine Light (CEL) isn't on.

Dumping the computer diagnostic codes on 86-95 Mustangs

Revised 26-July-2011. Added need to make sure the clutch is pressed when dumping codes.

Codes may be present even if the check engine light hasn’t come on, so be sure to check for them.

Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

Post the codes you get and I will post 86-93 model 5.0 Mustang specific code definitions and fixes. I do not have a complete listing for 94-95 model 5.0 Mustangs at this time.

Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes. On a manual transmission car, be sure to press the clutch to the floor.
Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.





If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.



The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.



The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.


WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems. This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and driveablity problems

Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off, and clutch (if present) is pressed to the floor, and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see Equus - Digital Ford Code Reader (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

Mustang distributors don't have octane rods? Mine does. Everyone I have owned does including my current 91 lx. Will post picture when I'm at the PC next. I think there even is a tsb describing why just changing initial timing by twisting distributor is different then installing the proper octane rod. To the OP try retarding then test drive. A -*3 octane rod may help your problem. Maybe not though.

Try plugging the vacuum line to the egr valve if you have one. It could be a bad egr valve or a bad egr position sensor giving advanced timing at idle instead of at cruising speed.

oatburner99 said:

Never, EVER heard of this...worked on the car tonight, did the KOEO steps, only got 11's (system pass) went to KOER, and got 44, 94, thermactor air injection system inoperative. I'm running a short belt bypassing my smog pump. So that leave code 19 that I recieved.which is RPM erratic and too low during test.

Soooooooooooo now what?

Click to expand...

Here is a pic of my dist with an octane rod installed. See the screw I circled, it retains an L shaped piece of flat stock that orients the pickup in relation to the distributor body. Any way its prob not your problem unless you have a heavily modified engine or a distributor from another application.

The guy who mentioned EGR may be on to something. BUt what is your idle speed when checking timing? Have you tried retarding it a little bit or not?

My apologies, I checked the Ford Factory service manual, and there is an "octane rod". The mysterious "octane rod" is just metal bracket that locks the position of the Hall effect sensor so that it does not move and change the base timing. If you were to use a longer or shorter "octane rod", it would change the ignition timing without losening the distributor and moving it. The "octane rod" becomes a non issue once you loosen the distributor and use a timing light to set the timing.



Code 19 - Engine off - No Vehicle Power (pins 37 + 57) or bad PCM VPWR Diagnosis. This is a wiring problem that is from a bad ECC power relay, bad connection, bad fuse link, bad ignition switch or a bad computer. The ECC relay is located on top of the computer under the passenger side kick panel. Pull the connector off any fuel injector and measure the voltage on the red wire: if its 12 volts or better, the ECC relay is OK. If the ECC relay is OK, pull the kick panel off and measure the voltage at pins 37 & 57. If it is 12 volts or more, then the computer's diagnostic firmware has taken a dump and is defective.

Code 19 - Engine running - Erratic idle during test (reset throttle & retest) - Idle Set Procedures .
See http://www.stangnet.com/mustang-forums/698148-help-me-create-surging-idle-checklist.html#post6855020 for the best way to set the mechanical base idle and cleaning procedure for the IAC/IAB.