1993 bank fire wont run on ether

brian84

Member
May 20, 2021
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new york
Hello all,
I have a 1993 5.0 stopped running. Oil pressure was low on the guage but it turns over and was running a bit rough and rich. It sounds like it wants to run and will run every 2 weeks for a bit but not long enough to get out and set timing. It seems like the ecm is bouncing the timing all over.
When it stopped, I had low fuel pressure. New pump, 50psi. I checked injector wiring. They work. I pulled them and checked outside the vehicle.
New timing chain, dist, map, wires, plugs cap and rotor. Double checked timing.
New ecm, New dist module. Compression 130.
WILL NOT START ON ETHER.
Are my lifters not pumping up except for residual oil?
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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If it does not start with spray than it's ignition related.
start here:
 

brian84

Member
May 20, 2021
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new york
If it does not start with spray than it's ignition related.
start here:
I have lots of spark and the injectors fire 4 time for each time the coil fires. I have changed every electronic part already which is why it has to be something mechanical.
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
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50 psi is way too much. Should be 39 psi with the vacuum off and capped.


Also, is this a original 93 Mustang 5.0 HO? You are describing batch fire injection which was on the standard output 5.0. The HO's are sequential so each injector should only pulse once vs all the injectors firing. What ECU are you using? What is the 3 digit code?
 
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manicmechanic007

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Sep 26, 2017
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2 weeks? What to dry out the plugs? You need to check the processor ground first. If you disconnect the processor ground the system flips to full rich
No lifter worries if the compression is 130
93 5.0 is stock?
You know about the spout plug you have to pull out to check the timing right?
Well there is a second one that when pulled jacks the timing10 degrees and richens the fuel ratio. It is for high mileage
Sometimes if the processor takes a sheet the timing will be all over
Pull that second spout and retest the timing. The run retard function will be disabled and sometimes it will run better and the timing will be back
Processor will be faulty
The second spout looking plug can be hard to find. It is sometimes near the processor in a takeout from the main loom
 

manicmechanic007

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Used to see the un cool disconnect the processor ground at the rear of the front head on Taurus
Makes the car fail I/M bad
Running so rich you could barely drive it
Shop had told them that it needed a ton of work for some big money.
Some were smart enough to come see us at the dealer
I would reconnect the ground and retest the I/M
Everything would be ok
Brian 84, Mustang 5L5 is right about the fuel pressure 50 is too much That is why I asked about it being stock or not
No good answers without all the info
 

brian84

Member
May 20, 2021
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new york
50 psi is way too much. Should be 39 psi with the vacuum off and capped.


Also, is this a original 93 Mustang 5.0 HO? You are describing batch fire injection which was on the standard output 5.0. The HO's are sequential so each injector should only pulse once vs all the injectors firing. What ECU are you using? What is the 3 digit code?
 
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brian84

Member
May 20, 2021
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new york
Thanks, I had 45-50 psi at the rail engine off so there was no vacuum to regulate it. While it may be too high, I have spark fuel and compression. They key here is that it wil start every 2 weeks if I disconnect battery with either ecm.
I still have a bad rear main and low oil pressure so it needs to be opened up. I heard no rod knocks when it ran and have not done a mechanical oil pressure guage yet to verify that but with the age I was going to freshen.
It's not here in front of me now so I will get the numbers later. Again, thanks for the input.
 

manicmechanic007

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Bank a and bank b injector drivers vs sequential which has 8 injector drivers
Uncommon but a driver fails once in a while and makes for some bad days and a tricky diagnosis
They usually only start failing after driving for about 40 minutes
Reminds me of the testing we used to have to do on the old Dura Spark systems
It was to aim a heat lamp at the module and wait for failure or a no spark
 

brian84

Member
May 20, 2021
13
3
13
44
new york
Used to see the un cool disconnect the processor ground at the rear of the front head on Taurus
Makes the car fail I/M bad
Running so rich you could barely drive it
Shop had told them that it needed a ton of work for some big money.
Some were smart enough to come see us at the dealer
I would reconnect the ground and retest the I/M
Everything would be ok
Brian 84, Mustang 5L5 is right about the fuel pressure 50 is too much That is why I asked about it being stock or not
No good answers without all the info
I had a Ford service manager go through this with me from another site where I paid for the service. This is why all the parts got changed. I vacuum tested the map and connected/ disconnected and jumped it to trick the ecm. We did the tests to set base timing bypassing the spouts. I ohmed everything and he couldn't provide any info other than to change things.
The motor turns like it is going to start, I have an inline spark tester and it's flashing but then the motor will slow down like the battery is dying or the timing is too far advanced. So far I have unwrapped the harness, ohmed out wires, grounded everywhere I could find. I think this one needs to come apart and I'm going to learn something.
 
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brian84

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May 20, 2021
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new york
2 weeks? What to dry out the plugs? You need to check the processor ground first. If you disconnect the processor ground the system flips to full rich
No lifter worries if the compression is 130
93 5.0 is stock?
You know about the spout plug you have to pull out to check the timing right?
Well there is a second one that when pulled jacks the timing10 degrees and richens the fuel ratio. It is for high mileage
Sometimes if the processor takes a sheet the timing will be all over
Pull that second spout and retest the timing. The run retard function will be disabled and sometimes it will run better and the timing will be back
Processor will be faulty
The second spout looking plug can be hard to find. It is sometimes near the processor in a takeout from the main loom
 

brian84

Member
May 20, 2021
13
3
13
44
new york
The Ford guy said 130 was low. IMO it should run. The new plugs read rich however they are bone dry. If my fuel pressure is too high they should be wet and compression take a dump. The ether should dry it out. I did do the module bypass to check the ecm as well.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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Some sideline observations, 130 psi cold cranking compression would not be 'too low', you may have a weak spark and/or timing issue, injector should squirt once per timing event, now the computer is suspect,
I'm not going to jump back and forth to see if this is a new purchase for you, these cars get all F'd up because owners don't know how to properly diagnose or get bad advice from a keyboard repair man, and then get frustrated and sell the problem to someone else.I
Try cranking with the gas peddle on the floor, WOT will stop the injector pulse and still light the sparklers.
The computer was mentioned as being suspect, mostly because of the batch fire comment, have you tried to pull codes?
 

manicmechanic007

Active Member
Sep 26, 2017
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I had a Ford service manager go through this with me from another site where I paid for the service. This is why all the parts got changed. I vacuum tested the map and connected/ disconnected and jumped it to trick the ecm. We did the tests to set base timing bypassing the spouts. I ohmed everything and he couldn't provide any info other than to change things.
The motor turns like it is going to start, I have an inline spark tester and it's flashing but then the motor will slow down like the battery is dying or the timing is too far advanced. So far I have unwrapped the harness, ohmed out wires, grounded everywhere I could find. I think this one needs to come apart and I'm going to learn something.
The Service Manager at a Ford dealer should know his stuff but..
If it still wont run you need to recheck the big 3
Spark fuel and compression. Compression first in your case. Not common on 5.0 to jump time but pull a valve cover and check the valve timing
Note If the distributor is not turning it will still have spark. One spark each time the key is turned to crank
85 lbs of compression is not enough. Needs close to 130
Leaving out the fuel quality test
If it will not run on ether there is no reason to test the fuel right now
 

manicmechanic007

Active Member
Sep 26, 2017
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130 is not low but a brand new one may have 145 or so
130 is sure enough to start the car
I do not want to know what they said the compression is
I do want you to test it and report back
Once had a pile BMW 540 V8 supposed to have 145 would not start at 125 added some coolant and it fired right up.
The head gaskets were leaking
 

brian84

Member
May 20, 2021
13
3
13
44
new york
Some sideline observations, 130 psi cold cranking compression would not be 'too low', you may have a weak spark and/or timing issue, injector should squirt once per timing event, now the computer is suspect,
I'm not going to jump back and forth to see if this is a new purchase for you, these cars get all F'd up because owners don't know how to properly diagnose or get bad advice from a keyboard repair man, and then get frustrated and sell the problem to someone else.I
Try cranking with the gas peddle on the floor, WOT will stop the injector pulse and still light the sparklers.
The computer was mentioned as being suspect, mostly because of the batch fire comment, have you tried to pull codes?
the bank fire is supposed to fire more than once per revolution as 4 injectors all share the same ground -or so I am told the noids throw 4 injector pulses for every spark. No codes. 2 computers do the same thing however I was suspect the computer was throwing the timing way out of whack. Chain is new.
I had the pedal wot. With ether the is no piff paff, no backfire. The spark is jumping fine across 2 spark testers.
Thanks for your help! It will get better someday......
 

brian84

Member
May 20, 2021
13
3
13
44
new york
The Service Manager at a Ford dealer should know his stuff but..
If it still wont run you need to recheck the big 3
Spark fuel and compression. Compression first in your case. Not common on 5.0 to jump time but pull a valve cover and check the valve timing
Note If the distributor is not turning it will still have spark. One spark each time the key is turned to crank
85 lbs of compression is not enough. Needs close to 130
Leaving out the fuel quality test
If it will not run on ether there is no reason to test the fuel right now
Front cover is not installed. Timing marks line up, distributor turns. I don't see why I would pull valve covers but will anyways. I was heading down the bad head gasket theory and removed the AF. I've had it wash down cylinders before. I drove this with a bad miss around the shop about 5 times
130 is not low but a brand new one may have 145 or so
130 is sure enough to start the car
I do not want to know what they said the compression is
I do want you to test it and report back
Once had a pile BMW 540 V8 supposed to have 145 would not start at 125 added some coolant and it fired right up.
The head gaskets were leaking

, no smoking out tailpipe, no AF consumption just low oil pressure on the dash guage. I usually do valve jobs and heads on everything I own just to be on the safe side so I guess I will freshen the motor and go from there.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
20,620
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polk county florida
Ok, say you rebuild the engine, stuff it back in and you still have a 'no start' condition. Just say'n, I would like to know why there is a 'batch fire' symptom when the car is supposed to be SFI.
What is the firing order, HO or non HO?
And what computer is it using?
just trying to help.
 
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manicmechanic007

Active Member
Sep 26, 2017
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Ok, say you rebuild the engine, stuff it back in and you still have a 'no start' condition. Just say'n, I would like to know why there is a 'batch fire' symptom when the car is supposed to be SFI.
What is the firing order, HO or non HO?
And what computer is it using?
just trying to help.
You absolutely right. Something is amiss. How long you owned the car? What is the history?