Bad Coil?

[turbo2256b]

I have run a MSD coil for years maybe around 10 or more. One must beware there are MSD knock offs on most all of their products. one reason I dont purchase stuff off fleabay but places like Summit or Jeggs for the most part.

Fairly sure Motorcraft plugs are made by Autolite still. i CURRENTLY RUN aUTOLITE ar-33s AS BF-32s would be best but that heat range in any plug brand has been discontinued.

[turbo2256b]

The coils I HAVE SEEN THE MOST ISSUES WITH ARE COIL ON PLUG ones. Hands are really shot today.

[BigT]

Update...new BWD coil seemed to help a little and so did upping the idle. I adjusted the TPS, but no changes. After a warm up, I ran a code scan. Came up with code 21-Engine Coolant Temperature (ECT) sensor out of rang. I'm also smelling a rich condition.

I think this could be my problem. What say the masses?

[87Topaz]

I have run a MSD coil for years maybe around 10 or more. One must beware there are MSD knock offs on most all of their products. one reason I dont purchase stuff off fleabay but places like Summit or Jeggs for the most part.

Fairly sure Motorcraft plugs are made by Autolite still. i CURRENTLY RUN aUTOLITE ar-33s AS BF-32s would be best but that heat range in any plug brand has been discontinued.

For a while, Autolites were made by Honeywell and now are a division of an investment group but marketed under FRAM. I think Ford "subs" out the manufacturing of Motorcraft parts, in general, so not sure who actually makes the plugs.

[gadget73]

Last batch of Autolite I got came from China, Motorcraft come from Mexico. Don't know if they moved Autolite manufacturing to Mexico but those China ones ran like crap.


Code 21 if the engine is warmed up says the ECT is dead or has a wiring problem to it. If its plugged in, check the resistance. http://www.grandmarq.net/oldfuelinjection/page28.html

If that checks OK, something is up with the wiring.


Did you get the orange ground wire connected back to the lower intake? If not, it will make the sensors lie. It comes out of the harness that feeds to the oxygen sensors and usually grounds to one of the bolts on the back of the lower intake if it doesn't bolt to the cylinder head.

Either way, without temperature input, the fuel mix will be wrong and it will never use the oxygen sensors to trim it.

[BigT]

Last batch of Autolite I got came from China, Motorcraft come from Mexico. Don't know if they moved Autolite manufacturing to Mexico but those China ones ran like crap.


Code 21 if the engine is warmed up says the ECT is dead or has a wiring problem to it. If its plugged in, check the resistance. http://www.grandmarq.net/oldfuelinjection/page28.html

If that checks OK, something is up with the wiring.


Did you get the orange ground wire connected back to the lower intake? If not, it will make the sensors lie. It comes out of the harness that feeds to the oxygen sensors and usually grounds to one of the bolts on the back of the lower intake if it doesn't bolt to the cylinder head.

Either way, without temperature input, the fuel mix will be wrong and it will never use the oxygen sensors to trim it.

On the back of the heads each had a grounding wire (connected) with the O2 sensors, and the passenger side had an extra grounding wire which I don't know where it went. The negative wire from the battery is attached to the front of the block.

I should say, that the car ran fine for a couple of days, then I did some work on it. One of the things I did was flush out the coolant system due to the stop leak I used. I may have not let the sensor cool down enough before I sent cold water from the garden hose through the system to clean out the old water. I'm just using distilled water until I get things completed.

[turbo2256b]

cOOANT TEMp SENSORS and faulty thermostats can have some of the biggest effects on the fuel curve usually causing an overly rich condition. Some after juicing up their engines a bit would pull the plug on the temp sensor at the drags to richin the fuel curve others would install a lower temp thermostat.

One of the things i did which helped me reach the 32.9 MPG was to make sure every sensor was checked for optimum range given in Fords repair manuals including a check of the thermostat opening closing points. Thermostats have about the widest tolerance range about + or - 25% of its marked opening.
I used to pull sensors out of U pull yards every chance I GOT AND CHECK THEIR RANGE as sometimes they were better than new ones I CHECKED.

[BigT]

cOOANT TEMp SENSORS and faulty thermostats can have some of the biggest effects on the fuel curve usually causing an overly rich condition. Some after juicing up their engines a bit would pull the plug on the temp sensor at the drags to richin the fuel curve others would install a lower temp thermostat.

One of the things i did which helped me reach the 32.9 MPG was to make sure every sensor was checked for optimum range given in Fords repair manuals including a check of the thermostat opening closing points. Thermostats have about the widest tolerance range about + or - 25% of its marked opening.
I used to pull sensors out of U pull yards every chance I GOT AND CHECK THEIR RANGE as sometimes they were better than new ones I CHECKED.

I plan on getting a new one from O'Reilly's. How do you check them? With a heat gun? Hot water?

[DerekTheGreat]

I've seen people heat up water in a beaker with a verified thermometer in there to check them.

[BigT]

I've seen people heat up water in a beaker with a verified thermometer in there to check them.

Sorry, I meant how do you test the sensors?

[gadget73]

ohm meter. If you haven't run the car all day, the water will be basically the same temperature as the air. If it reads about where you'd expect, chances are reasonable its not totally shot. If you want to test it beyond that, you'll need to stick it in a pot of water with a thermometer and heat it on the stove. Check the ohm reading against the chart to see if it matches up.

[BigT]

It’s running much better after installing the coolant temp sensor. I bumped up the idle, but may be too much, seemed a little high at stop lights. I also found the PCV hose they gave me expanded at the ends. I replaced them and took off the plastic "L" and connected directly on to the PCV valve. It ran good enough I drove it in to work today.

[DerekTheGreat]

Cool. What I like about GM computers from the same vintage is that our Snap-On MT2500 scanner allows us to "see" what all the sensors are doing and has tips how to manually test them. Ford and their "Advanced EEC-IV" doesn't. Hooking a scanner up to it is useless other than for finding codes. I can force the thing into some self test where sensors and relays click, idle increases but that doesn't really do anything.. On the GMC it's how I found out the IAC valve is wonky, figured that anyway but the scanner showed me it's pretty far off target.

[gadget73]

They added streaming data around 1993 with the 3 digit error code ECM's. What we have doesn't give that info unless you have a tuner. I've been with John in his car with the QuarterHorse and it will tell you what everything is doing at all times. The original FOrd way was to use this "vampire tap" thing that went between the ECM and the harness and came out to this device that could record stuff. I've never used or seen one in person but it looks awkward as all get-out and quite limited as well. I think you can only look at a couple of things at a time. The other way is to use the breakout box and read raw sensor data with a meter and cross that over to a chart that told you what was going on.

[DerekTheGreat]

Ah, the breakout box. We just got this huge black binder shop manual from Ford for 1988 stuff, it mentions that. It's freakin' cool. Has mass air flow stuff too, hell it has everything in it for all kinds of 1988 crap. If anyone needs something I can help out. My lack of functioning CEL bothers me, especially any time I drive Ashley's. Cross referencing a Mark VII EEC-IV pinout diagram with a Town Car one shows no difference between them, it's supposedly wired. But the light seems to be triggered from EEC-IV diagnostic harness, the same one I had to use a jumper wire with to connect terminals in order to read my car, but not so with Ashley's 89, which was simple plug and play with the jumper already integrated. Perhaps if I jumper this wire at all times I will have a CEL. I dunno, the diagram also shows a wire going to the ignition for the "run" position. I did harvest a 89 warning light pod to contrast against my 88 and there was not one difference between them, wires all the same, printed circuit is the same ect. Gotta be a fairly simple way to get the thing to work... I'll have to look into this QuarterHorse thing...