Technical => Engine Tech => Topic started by: SLEEPER T-BIRD 87 on May 16, 2009, 09:38:45 PM
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 16, 2009, 09:38:45 PM
Ok having some issues with my 5.0 maverick the ecm/harness/sensors etc are out of a 1990 E250 ford van ran great yesterday,went to start it today and it wouldnt fire injectors are pulsing,so i swapped distributors and modules still no ignition fire,swapped coil no fire I have 12v at the coil and at the ignition module wires and pulse from the module.only time it will fire is when you cycle the key on to off.
WTf is going on.its always fired on the first hit of the key and now is instantly dead.
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 17, 2009, 12:09:17 AM
A no spark condition has to be the Dist, module, coil or no power to the coil/module... I've made plenty of sparks spinning a dist with it and the coil connected up on the workbench... Since you've changed the dist and coil, I'd be rechecking the wiring...
Title: 5.0 DOA (ford techs) ENTER
Post by: softtouch on May 17, 2009, 12:17:23 AM
Sounds like the tach side of the coil (the side that goes to the ignition module) is grounded all the time.
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 17, 2009, 09:53:04 AM
Quote from: softtouch;272744
Sounds like the tach side of the coil (the side that goes to the ignition module) is grounded all the time.
I get pulse from the distributor when spinning the motor over but no fire
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 17, 2009, 09:56:01 AM
Quote from: TurboCoupe50;272743
A no spark condition has to be the Dist, module, coil or no power to the coil/module... I've made plenty of sparks spinning a dist with it and the coil connected up on the workbench... Since you've changed the dist and coil, I'd be rechecking the wiring...
That was my thought as well.Ive ran back over the wiring for loose connections etc,the engine harness and the main harness are uncut.
We did have a bad lightning storm that night what are the chances that maybe the ecm got fried?
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 17, 2009, 10:28:26 AM
The ECM has nothing to do with making spark, only controls advance... I didn't have a computer when I ran the test on the workbench...
Maybe if the ECU has a issue and was confusing the module advance circuitry, but you could disconnect the ECM and prove that...
[COLOR="red"]And guess what gang?? That was the problem...[/COLOR]
The computer system was down in that '88 Vert Stang I had, that had been under water, due to a bad ecu relay... Wouldn't run but it made spark...
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 17, 2009, 10:34:00 AM
Quote from: TurboCoupe50;272778
The ECM has nothing to do with making spark, only controls advance... I didn't have a computer when I ran the test on the workbench... Maybe if it had a issue and was confusing the module advance circuitry, but you could disconnect the ECM and prove that...
The computer system was down in that '88 Vert Stang I had, that had been under water, due to a bad ecu relay... Wouldn't run but it made spark...
Ill try disconnecting the ecm at this point its worth a try.
Title: 5.0 DOA (ford techs) ENTER
Post by: V8Demon on May 17, 2009, 11:24:08 AM
The following is from Joel5.0 @ SBFtech. Hope it helps.
Quote
No Start due to No Spark
Needed Tools/Chemicals:
* 12-vdc Test Light * Carburetor Cleaner Spray Can * ½" combination wrench * TFI Ignition System Wiring Diagram
To start trying to identify if it's a fuel or a spark problem, place ign key in on, check for the fuel pump priming sound, if OK or NOK, remove the breather hose from the throttle body and spray some carburetor cleaner through the TB port.
Attempt to start engine, if engine starts for a couple of seconds and dies, the problem is a No Fuel condition....if the engine doesn't start at all, the problem is a No Spark condition...
NO Spark
Loosen distributor holding bolt with ½" wrench, remove plug from coil, turn ign on, while holding the coild plug ~ ?" away from the coil tower, rotate distributor left-right-left....spark doesn't arc from coil to plug = next step...spark arcs from coil to plug = check condition of distributor rotor and cap, and replace.
Place ignition key in on, with the 12-vdc test light connected to a good ground, probe the (+) terminal at the coil (Red/Lt Green wire)...test light off = usually an ignition switch or 20 GA fuse link problem....test light on = next step.
Place ignition key in on, with the 12-vdc test light connected to a good ground, probe the (-) terminal at the coil (Tan/Yellow wire)...test light off = replace coil, test light on = next step.
Place ignition key in on, with the 12-vdc test light connected to a good ground, probe the (-) terminal at the coil (Tan/Yellow wire), rotate distributor left-right-left and check test light...test light blinks = replace coil....test light on = next step.
Ign On, backprobe or disconnect TFI and check with test light, pin #4 (ICM Power)...test light on = next step, test light off = open problem in wiring that needs tracing and repair.
Up till now the problem is either a TFI module, or a stator sensor failure. Your options are to either replace the module and check if it starts, or follow this testing procedure ------> http://351winsor.com/joel/Ignition_Systems/tfi2.html to rule out/id the module as the culprit, and replace the stator sensor, TFI module, or both....I usually recommend the latter one for these cases anyway.....
I'll add to this as well that it in fact CAN be the ECU. Here's why:
Quote
Another reason for an EFI No Start, is that the ECM is not turning on when the key is cycled to the IGN ON position. First you have to ID this is the case. In order to confirm if the ECM is not activating, notice if the fuel pump primes when the key is rotated to IGN ON, if it does prime.....the ECM is turning on.....if it doesn't.....measure for 5 vdc VREF voltage at any of the 3-wire sensors (EVP, TPS or MAP/BP), we will use the TPS for this explanation.
Check for 5 vdc, IGN ON between the RED/ORANGE wire and a good ground like battery (-)......if 5 vdc is present, THE ECM is turning on.....not present.....next!
Check the EEC ground near the battery, it should be attached to the battery (-) or the frame.
Check the EEC relay located on top of the ECM in the passenger kickpanel, make sure it has 12-vdc "always hot" at one of the relay terminals....if not, you need to trace the "always-hot" wire to the correspondent fuselink located in the starter solenoid.
Make sure the IGN ON relay terminal switches to 12-vdc when you turn the ignition key....if not, you either have a wiring open, a bad ignition switch assy., or an open fuselink.
Make sure pin #1 at the ECM connector has 12-vdc "always hot", and that pins 37 and 57 have 12-vdc when the key is switched to IGN ON otherwise, you have an open fuselink, or an open wire between the EEC relay and the ECM connector.
Also check pins 20, 40 and 60 at the ECM connector to ground (resistance check).....if you have >5Ω resistance to a good ground reference point, the ground wires have an open somewhere.
If all the above checks OK.....the ECM is fubar.
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 17, 2009, 12:24:07 PM
NEVER seen a case where the ECU caused NO spark, and doubt it can happen... Don't care what the write up says..
My first experience was pulling the computer on a '87 4 cyl Stang, and checking spark, was still there... Bad EEC relay on that drown '88 5.0, Stang vert still had spark(it ran once I repl'd the relay)... Dist and coil laying on work bench, no computer with in 10ft, still made spark...
Title: 5.0 DOA (ford techs) ENTER
Post by: V8Demon on May 17, 2009, 12:49:46 PM
These ECU's are bulletproof, but that writeup comes from one of the few I trust as far as EEC info is concerned. From what I understand you're supposed to have the initial spark without the ECU in place.
Quote
no computer with in 10ft, still made spark...
Made spark? Or started?
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 17, 2009, 12:55:01 PM
Quote from: V8Demon;272802
Made spark? Or started?
The dist and coil were laying on the work bench, just connected together with jumper leads... No car, no ECU, no relay, nothing but a 12v power source... Spun the dist by hand and the coil produced spark...
My Tbird race buddy has switched his car to carb and is still running the orig EEC dist and no computer... Has the timing dialed up to about 25* advance, runs fine, but he plans on switching to a dist with internal advance...
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 17, 2009, 01:30:25 PM
starts right up with the spout out,If i plug it back in with it running it dies instantly.
meaning it has spark with it out and none with it in
what does this mean?
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 17, 2009, 02:00:53 PM
Uoooo don't sound good... Reread my 2nd post, we may find the ECU will kill spark yet... The SPROUT signal comes from the ECU, possibly there is a bad signal/voltage being sent from it... I know a shorted SPROUT signal won't keep one from running, and neither will a open SPROUT... Possibly you are correct about the T-storm causing the issue...
When I tested the dist & coil on the workbench the SPROUT was not connected...
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 17, 2009, 02:17:40 PM
Quote from: TurboCoupe50;272811
Uoooo don't sound good... Reread my 2nd post, we may find the ECU will kill spark yet... The SPROUT signal comes from the ECU, possibly there is a bad signal/voltage being sent from it... I know a shorted SPROUT signal won't keep one from running, and neither will a open SPROUT... Possibly you are correct about the T-storm causing the issue...
When I tested the dist & coil on the workbench the SPROUT was not connected...
i just checked the spout wire from the ecm and it was showing 12.87v from the computer
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 17, 2009, 02:28:53 PM
I dunno what should be on the SPROUT, but sounds like you have battery voltage, likely not good....Do you have another vehicle you can compare it to??? If not, I can possibly run out to the garage and check my Bird(I have a bad cold and it's raining, so the wife would bitch)....
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 17, 2009, 02:31:07 PM
Quote from: TurboCoupe50;272816
I dunno what should be on the SPROUT, but sounds like you have battery voltage, likely not good....Do you have another vehicle you can compare it to??? If not, I can possibly run out to the garage and check my Bird(I have a bad cold and it's raining, so the wife would bitch)....
its the only ford fuel injected car i have anymore so nothing to compare it to
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 17, 2009, 02:40:49 PM
Ahhh wife's asleep, made it out to the garage and back undetected... :D
From the computer I measured .04v with the ign sw on(0v off)... Didn't try to start it as it would have awakened the XYL...
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 17, 2009, 02:43:08 PM
Quote from: TurboCoupe50;272818
Ahhh wife's asleep, made it out to the garage and back undetected... :D
From the computer I measured .04v with the ign sw on(0v off)... Didn't try to start it as it would have awakened the XYL...
Then i guess it safe to say the part of the computer that controls the timing advance is fried and sending battery voltage to the spout connection on the module? I didnt check the voltage on mine running either
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 17, 2009, 02:50:50 PM
Yup, unless the sprout wire is shorted to a 12v supply, your ECU is likely FUBAR... I would pull the computer and make sure the voltage disappears...
Well I learned something today...
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 17, 2009, 02:56:26 PM
Quote from: TurboCoupe50;272821
Yup, unless the sprout wire is shorted to a 12v supply, your ECU is likely FUBAR... I would pull the computer and make sure the voltage disappears...
Well I learned something today...
Me and you both ive never seen one do this before.
On a side note i may just set the timing about 32* and leave the spout out untill i can find a computer
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 17, 2009, 03:02:44 PM
It'll probably be hard to start when hot with that much timing... Maybe 25*...
When I ran the Bird at the strip with the advance locked at 32*, I had a starter button on it so I could spin the starter and then flip on the ignition...
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 17, 2009, 03:55:21 PM
Quote from: TurboCoupe50;272823
It'll probably be hard to start when hot with that much timing... Maybe 25*...
When I ran the Bird at the strip with the advance locked at 32*, I had a starter button on it so I could spin the starter and then flip on the ignition...
I just got back home i set it to 32* seems to start ok hot. Im tempted to sell this fuel injected stuff and go back carb on this thing.
Title: 5.0 DOA (ford techs) ENTER
Post by: V8Demon on May 17, 2009, 04:21:22 PM
Quote
Ahhh wife's asleep, made it out to the garage and back undetected...
Thought I was the only person that did this :p
Quote
Well I learned something today...
:grinno:
Seems your way to test it is a LOT more simple then the writeup I posted. ;)
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 17, 2009, 06:27:19 PM
Quote from: SLEEPER T-BIRD 87;272828
Im tempted to sell this fuel injected stuff and go back carb on this thing.
No doubt one solution, but after having that torquie EFI setup I suspect you'd be sorry...
A buddy had a '83 Toyota P/U with carbed 302(stock but had a fresh set of E7 heads), wasn't anywhere as quick as I thought it would be... My bird that weighs 1000lb more, would run off and hide from it...
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 18, 2009, 06:20:11 PM
Quote from: TurboCoupe50;272845
No doubt one solution, but after having that torquie EFI setup I suspect you'd be sorry...
A buddy had a '83 Toyota P/U with carbed 302(stock but had a fresh set of E7 heads), wasn't anywhere as quick as I thought it would be... My bird that weighs 1000lb more, would run off and hide from it...
i ordered a computer today:D
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 20, 2009, 07:37:42 PM
put the new computer in runs great
Title: 5.0 DOA (ford techs) ENTER
Post by: V8Demon on May 20, 2009, 07:42:04 PM
Cool! Glad it worked out ;)
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 24, 2009, 08:07:32 PM
and now back doing the same thing again....pretty sure its juts a bad parts store ecm
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 24, 2009, 08:47:27 PM
Is the ECM grounded properly??? This also includes grounding the shielding on the harness out to the TFI...
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 24, 2009, 09:44:08 PM
Quote from: TurboCoupe50;274157
Is the ECM grounded properly??? This also includes grounding the shielding on the harness out to the TFI...
yeah I cant stress the trouble i went through to make this as it would be "stock" meaning everything is hooked up and works as new.
Im guessing maybe the van that donated this computer to be "rebuilt" probly had the same issue we all know how great parts you get from the chain stores are now days.I scanned the codes after i installed the reman ecm and all it had was a o2 code.SO i got a new o2 today and put it in and calplowie
Title: 5.0 DOA (ford techs) ENTER
Post by: Lightningbird on May 25, 2009, 12:58:41 AM
It sounds like a computer grounding issue to me. I once wired my ignition box incorrectly and it did the same thing. I also have left the ground wiring near the starter solenoid ungrounded and it did this also. Please check all the grounds for the FI system cause it sounds exactly like a ground problem. Just like when corrosion builds up between the battery terminals, the grounds will do the same if the humidity is high enough. Happened to me a few times for my Nitrous System when living on the gulf coast.
Title: 5.0 DOA (ford techs) ENTER
Post by: SLEEPER T-BIRD 87 on May 26, 2009, 07:11:50 PM
computer pin 60 im guessing out of the original computer was stuck in the ecm connector pushing pin 60 out of the harness. Pin 60 is the ground
Title: 5.0 DOA (ford techs) ENTER
Post by: TurboCoupe50 on May 26, 2009, 08:13:04 PM
I believe pin 40 is also ground, but they possibly connect to different points on the PCB...