Joe, you will overcome. And when you do, it will be glorious.
Won't start - no spark after rebuild
- Thread starter jcarter
- Start date
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Test the coil first because it is easy and informative:
Disconnect the wires at the - side of the coil.
Turn the key on.
Momentarily jump between the - lug of the coil and ground.
When you break the ground, you should get a spark out of the center wire.
If it sparks, then everything upstream of the coil to the battery is fine and the culprit is the pickup and ignitor that grounds the coil.
Disconnect the wires at the - side of the coil.
Turn the key on.
Momentarily jump between the - lug of the coil and ground.
When you break the ground, you should get a spark out of the center wire.
If it sparks, then everything upstream of the coil to the battery is fine and the culprit is the pickup and ignitor that grounds the coil.
OK folks. We're all jumping ahead before any diagnostics are performed.
We KNOW that the existing AFM is faulty as the CEL won't illuminate when it's plugged in and it does when the AFM is not plugged in. He pulled out the connector mounted on the AFM and severed the internal connections. It must be repaired or replaced.
In its current condition, the EFI circuit is dead. There will be no spark.
Once the AFM is replaced with one that works, we'll have to see where we are. There is no logic in guessing what "may be wrong". Let's diagnose the issues as they arise.
What can be done is to jump out the fuel pump logic on the CHECK CONNECTOR by jumping pin 1(FP) to pin 8(B+), unplug the AFM, and see if the truck fires. It will run poorly without an AFM. It will also throw a code and illuminate the CEL while running. Please remember to remove the jumper after you're done playing around. Otherwise the FP will fire every time the key is in the ON position. Also, if you decide to go this route, remove the 15 amp EFI fuse in the under hood fuse box for about 5 or so minutes to clear any codes when you're done. THis will keep us from going down the primrose path when you replace the AFM with a known good one.
Or you can individually check all the components with your meter. In my flowchart there is the FSM test for the ignition coil and distributor coils.
We KNOW that the existing AFM is faulty as the CEL won't illuminate when it's plugged in and it does when the AFM is not plugged in. He pulled out the connector mounted on the AFM and severed the internal connections. It must be repaired or replaced.
In its current condition, the EFI circuit is dead. There will be no spark.
Once the AFM is replaced with one that works, we'll have to see where we are. There is no logic in guessing what "may be wrong". Let's diagnose the issues as they arise.
What can be done is to jump out the fuel pump logic on the CHECK CONNECTOR by jumping pin 1(FP) to pin 8(B+), unplug the AFM, and see if the truck fires. It will run poorly without an AFM. It will also throw a code and illuminate the CEL while running. Please remember to remove the jumper after you're done playing around. Otherwise the FP will fire every time the key is in the ON position. Also, if you decide to go this route, remove the 15 amp EFI fuse in the under hood fuse box for about 5 or so minutes to clear any codes when you're done. THis will keep us from going down the primrose path when you replace the AFM with a known good one.
Or you can individually check all the components with your meter. In my flowchart there is the FSM test for the ignition coil and distributor coils.
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Hold on here. Are you saying that you're replacing a buggered AFM with one that has been buggered in the same way? Did I read that correctly?
- Thread starter
- #45
It's a good, used AFM & 1 step at a time
Good Used AFM:
No, no, no. He's selling a spare he bought. He has swapped it out to test and it works fine.
The "reason" he had the spare is he's an idiot like me. Thought that was ironic. I did it because I had to remove the air penum. He did it just being curious during a tune up. I would have been more angry if I did it during a tune-up.
Hold up:
I agree. The AFM didn't come today, hopefully tomorrow. I'll replace it and see if it starts. NO and we'll have some diagnosing to do. YES and I should be good to go. I'll still need to go through it a bit to make sure no codes are on. But with any luck, electronics are right. . . . Luck. . . ain't had too much of that lately.
Joe
Good Used AFM:
No, no, no. He's selling a spare he bought. He has swapped it out to test and it works fine.
The "reason" he had the spare is he's an idiot like me. Thought that was ironic. I did it because I had to remove the air penum. He did it just being curious during a tune up. I would have been more angry if I did it during a tune-up.
Hold up:
I agree. The AFM didn't come today, hopefully tomorrow. I'll replace it and see if it starts. NO and we'll have some diagnosing to do. YES and I should be good to go. I'll still need to go through it a bit to make sure no codes are on. But with any luck, electronics are right. . . . Luck. . . ain't had too much of that lately.
Joe
- Thread starter
- #46
Looking at the circuit in the FSM
"Copyright, Shmopyright". I realize I said "wait until AFM is replaced", but I have time to think through the ignition system.
Fusible Links: Per the circuit diagram, with key off, I should NOT get power at my coil. With key on, I should get power at my coil and if I do, that means the fusible links are good.
Coil: Basically just a transformer (12V in, ?V out). Does anybody know what voltage is on the load side of the coil? Also, it looks like the "new" voltage hits the igniter. I would have thought the coil would INCREASE the voltage to make a spark for combustion (high voltage, low amps). But diagram appears to put standard 12V to the distributor.
Distributor, Spark to plugs: In the diagram, wire from coil to center of distributor, current runs along rotor, then hits each plug wire as rotor turns. This needs to occur at precisely the right time in the engine (piston up high, compressing fuel air mixture, spark - BOOM! drives piston down). What is the voltage for the spark? Does the rotor simply take the current from the middle and "distribute" it to the cylinders? Then what are the 2 circuits in the distributor from the igniter, via the ECU?
Mystery Igniter + ECU: As I said, igniter has the "new" voltage. I think engine get's new voltage. So, can you explain the igniter, ECU with terminals IGT, IGF, NE & G (G with circle - is simply ground).
Should I see the professor after class?
Joe
PS I'm a professional electrical engineer, but try to use commonn sense as much as possible. Besides, I design buildings which are pretty easy. And have learned through mistakes, there is no MAJIC.
"Copyright, Shmopyright". I realize I said "wait until AFM is replaced", but I have time to think through the ignition system.
Fusible Links: Per the circuit diagram, with key off, I should NOT get power at my coil. With key on, I should get power at my coil and if I do, that means the fusible links are good.
Coil: Basically just a transformer (12V in, ?V out). Does anybody know what voltage is on the load side of the coil? Also, it looks like the "new" voltage hits the igniter. I would have thought the coil would INCREASE the voltage to make a spark for combustion (high voltage, low amps). But diagram appears to put standard 12V to the distributor.
Distributor, Spark to plugs: In the diagram, wire from coil to center of distributor, current runs along rotor, then hits each plug wire as rotor turns. This needs to occur at precisely the right time in the engine (piston up high, compressing fuel air mixture, spark - BOOM! drives piston down). What is the voltage for the spark? Does the rotor simply take the current from the middle and "distribute" it to the cylinders? Then what are the 2 circuits in the distributor from the igniter, via the ECU?
Mystery Igniter + ECU: As I said, igniter has the "new" voltage. I think engine get's new voltage. So, can you explain the igniter, ECU with terminals IGT, IGF, NE & G (G with circle - is simply ground).
Should I see the professor after class?
Joe
PS I'm a professional electrical engineer, but try to use commonn sense as much as possible. Besides, I design buildings which are pretty easy. And have learned through mistakes, there is no MAJIC.
I posted all this on my previos .PDF links...
The Engine speed is sensed via pick-up coils (NE pick-up & G Pick-up) in the distributor. This information is sent to the ECU to determine crankshaft position and engine rpm.
Then the igniter (wich is essentially an electronic relay) receives a "trigger" from the ECM (IGT) and responds by turning a higher amperage current to the ignition coil on and off.
Then Each time a spark is produced an ignition confirmation (IGF) signal is sent to the ECM.
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The HV side of the coil is an open circuit due to the spark gap. The signal on the load side of the coil is a pulse for each firing of the cylinder. When the ingitor grounds the coil, it magnetizes the core. When the ignitor interrupts the circuit, the magnetic field collapses, inducing a high voltage in the secondary. The voltage is limited by the potential required to arc across the spark gap, which depends on the distance and the dielectric value of the air/fuel charge. It typically varies from 10KV at idle to about 40KV at high load.
- Thread starter
- #49
Still waiting on the AFM, dad-gummed slow USPS!
I'm thinking about figuring out how to fix them and starting a business $150, send in yours like witchhunter does for injectors. Cdan said "22250-61010, it was used on FJ62 and FJ80 1988 to 1992" 6 years of these on 20+ year old vehicles means A LOT will be breaking, not to mention those 2 (evil, come and unscrew me, <evil laugh>) screws.
I've got tomorrow to install if comes in today. Thanks for your patience, for mine is GONE!
I'm thinking about figuring out how to fix them and starting a business $150, send in yours like witchhunter does for injectors. Cdan said "22250-61010, it was used on FJ62 and FJ80 1988 to 1992" 6 years of these on 20+ year old vehicles means A LOT will be breaking, not to mention those 2 (evil, come and unscrew me, <evil laugh>) screws.
I've got tomorrow to install if comes in today. Thanks for your patience, for mine is GONE!
- Thread starter
- #51
Waiting & playing
Put another 5 gallons of gas in her and aired up the front tires (had deflated a bit to make it a little lower & easier to get at).
Thought I'd play, so I "jumping pin 1(FP) to pin 8(B+)" just to see if I could get a "blip" of a "wanting to start". Nada. Played with timing adjustment - middle, to the right a bit, to the left a bit. Again Nada!
I'll wait on the AFM. I did a little research on Air Flow Meter vs Mass Air Flow sensor. WAY, WAY OVER MY HEAD!
Thanks for your patience folks. Next post will be with AFM in. . . Unless I get restless again.
Joe
Put another 5 gallons of gas in her and aired up the front tires (had deflated a bit to make it a little lower & easier to get at).
Thought I'd play, so I "jumping pin 1(FP) to pin 8(B+)" just to see if I could get a "blip" of a "wanting to start". Nada. Played with timing adjustment - middle, to the right a bit, to the left a bit. Again Nada!
I'll wait on the AFM. I did a little research on Air Flow Meter vs Mass Air Flow sensor. WAY, WAY OVER MY HEAD!
Thanks for your patience folks. Next post will be with AFM in. . . Unless I get restless again.
Joe
Did you disconnect the AFM first? The existing AFM is faulty causing a "no CEL" situation. When that happens, you won't get +12 to pin 8 and you won't have spark.
- Thread starter
- #53
AFM is IN!
First off, yes, AFM was unplugged.
Plan: Tonight, or maybe over lunchtime, I'll remove 15A EFI fuse in DS engine fuse block, install the good AFM, plug back in the fuse, tighten down the distributor, & try to start it.
One step down, hopefully not too many more to go. . . .
First off, yes, AFM was unplugged.
Plan: Tonight, or maybe over lunchtime, I'll remove 15A EFI fuse in DS engine fuse block, install the good AFM, plug back in the fuse, tighten down the distributor, & try to start it.
One step down, hopefully not too many more to go. . . .
- Thread starter
- #54
AFM is ON! Still no boom boom
I installed the used AFM, took out 15A EFI fuse, tightened down the distibutor, put 15A EFI fuse back in, and tried to start it.
NO
I did notice the CEL is ON when key is ON, so AFM did something, right?
I'll pull the fuse again, wait a good 10 minutes, put it back in and see, but I'm not too confident. Back in 10. . .
I installed the used AFM, took out 15A EFI fuse, tightened down the distibutor, put 15A EFI fuse back in, and tried to start it.
NO
I did notice the CEL is ON when key is ON, so AFM did something, right?
I'll pull the fuse again, wait a good 10 minutes, put it back in and see, but I'm not too confident. Back in 10. . .
- Thread starter
- #55
Ignition Diagnostic
Still NO!
What's next? (in order):
Still NO!
What's next? (in order):
- Thread starter
- #56
Can i do this? Should i try?
#1 I think I'll test everyting in the distributor. I had it out, thus, more prone to damage, although I don't remember dropping it. I did bang on it a bit trying to put it in (brass rod, bang on bolt hole at bottom to try and get it in), not BANG, just bang. Maybe it vibrated something loose or bad.
I'm done for tonight, but can be back on it tomorrow night & Friday.
May need to price a new distributor. . . .
This is very frustrating, getting colder by the day, thought I was done, was very patient, cleaned everything, double checked tightening of all bolts, took time, etc.
Also, I know I'm going to test EVERYTHING, spend all kinds of time freezing my arse off, and finally find something stupid.
MAYBE IT'S TIME TO GIVE UP AND BRING IT IN?
Maybe the ignition is WAY over my head and should let a professional do it. Of course, they'll probably spend HOURS diagnosing, tell me it's a bad WHATEVER, I get a new one and NO GO still.
CONFUSED! Maybe it's worth the money, but I don't trust most mechanics. I'll call my favorite to see what they say.
#1 I think I'll test everyting in the distributor. I had it out, thus, more prone to damage, although I don't remember dropping it. I did bang on it a bit trying to put it in (brass rod, bang on bolt hole at bottom to try and get it in), not BANG, just bang. Maybe it vibrated something loose or bad.
I'm done for tonight, but can be back on it tomorrow night & Friday.
May need to price a new distributor. . . .
This is very frustrating, getting colder by the day, thought I was done, was very patient, cleaned everything, double checked tightening of all bolts, took time, etc.
Also, I know I'm going to test EVERYTHING, spend all kinds of time freezing my arse off, and finally find something stupid.
MAYBE IT'S TIME TO GIVE UP AND BRING IT IN?
Maybe the ignition is WAY over my head and should let a professional do it. Of course, they'll probably spend HOURS diagnosing, tell me it's a bad WHATEVER, I get a new one and NO GO still.
CONFUSED! Maybe it's worth the money, but I don't trust most mechanics. I'll call my favorite to see what they say.
TrickyT
Hate that mud...
Have you followed the FSM test procedure for the ignition? It starts on page IG-5, which is the next page after the one you showed in post #46. This includes testing pickup coil resistances, as described on IG-7.
Have you followed the "troubleshooting with a volt/ohmmeter" section of the manual which starts on page FI-27? This includes testing the new AFM you got as described on page FI-66.
Have you run the starter with the distributor cap removed to ensure that the distributor is actually rotating? If there are no signals to the ECU from the pickup coils in the distributor, the ignition circuit will never fire.
Buying new parts like the AFM and distributor is going to get expensive real fast. The 3FE is about as far away from rocket science as you can get, so just stick with it and plow on forward. You need to methodically go through each of the troubleshooting sections of the FSM and follow the steps given there. Post up anything about your vehicle that doesn't conform to the FSM tests. 'Mud is a great source of collective wisdom, but no one here can just "divine" what's wrong without empirical data from you. You've done a great job with the rebuild so far and now just need to nail this electrical issue. This will require a different thinking cap then the melted piston hat you recently wore. Wish I lived closer to Missouri so I could drop by and get 'ya going.
Have you followed the "troubleshooting with a volt/ohmmeter" section of the manual which starts on page FI-27? This includes testing the new AFM you got as described on page FI-66.
Have you run the starter with the distributor cap removed to ensure that the distributor is actually rotating? If there are no signals to the ECU from the pickup coils in the distributor, the ignition circuit will never fire.
Buying new parts like the AFM and distributor is going to get expensive real fast. The 3FE is about as far away from rocket science as you can get, so just stick with it and plow on forward. You need to methodically go through each of the troubleshooting sections of the FSM and follow the steps given there. Post up anything about your vehicle that doesn't conform to the FSM tests. 'Mud is a great source of collective wisdom, but no one here can just "divine" what's wrong without empirical data from you. You've done a great job with the rebuild so far and now just need to nail this electrical issue. This will require a different thinking cap then the melted piston hat you recently wore. Wish I lived closer to Missouri so I could drop by and get 'ya going.
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- Thread starter
- #58
Playing Ignition Wizard for Halloween
Questions about testing:
Tests:
1. Page IG-5: Says "disconnect high-tension cord from distributor" is this the one from the coil or do they mean ANY plug wire? Hold it near body (ground) and check for spark.
2. Meter: Got to get a new one for Primary Coil Resistance (0.3 - 0.6 ohms). Recommendations on good, cheap meter? Maybe try Harbor Freight and check for low ohms (less than 1) before I leave the store.
3. Rule out Ignitor & Coil First: Coil=$100, Igniter=$500. I don't trust my "metering skils" is there an easy check for this? There is 1 wire from coil to distributor, can't I check for spark coming from coil or will ECU prevent this spark if distributor pick-ups are bad? Regardless, I'll start at page IG-7, primary coil resistance, secondary coil resistance.
4. Easy check: Take off distributor cap and rotor, make sure they "look right".
5. Distributor: $650. Test gaps & pickup coil resistance. I assume to test pickup coil, I unplug the distributor and check plug going to the distributor, right?
6. What about codes? Should I check codes (TE1-E1 jump, count CEL blinking)? Will this tell me anything? FSM says "normal operating temperature", does it work when cold?
7. Fuel Injection System: FSM has 90 pages of this! Lot of work. I'll start with IG section, then move to FI section. Starting with AFM test (good tip!).
I think if I do go through all this crap, I'll start understanding the ignition system like I now understand the block. Hopefully this can be accomplished in about 20 hours which I should be able to put in by end of day Sunday. Next week will be a KILLER to the checkbook, but next weekend I should have it running.
Depressing, but I'll put my head down and plow ahead. Hopefully I can get a buddy to right down test numbers to make it go quicker.
Questions about testing:
Tests:
1. Page IG-5: Says "disconnect high-tension cord from distributor" is this the one from the coil or do they mean ANY plug wire? Hold it near body (ground) and check for spark.
2. Meter: Got to get a new one for Primary Coil Resistance (0.3 - 0.6 ohms). Recommendations on good, cheap meter? Maybe try Harbor Freight and check for low ohms (less than 1) before I leave the store.
3. Rule out Ignitor & Coil First: Coil=$100, Igniter=$500. I don't trust my "metering skils" is there an easy check for this? There is 1 wire from coil to distributor, can't I check for spark coming from coil or will ECU prevent this spark if distributor pick-ups are bad? Regardless, I'll start at page IG-7, primary coil resistance, secondary coil resistance.
4. Easy check: Take off distributor cap and rotor, make sure they "look right".
5. Distributor: $650. Test gaps & pickup coil resistance. I assume to test pickup coil, I unplug the distributor and check plug going to the distributor, right?
6. What about codes? Should I check codes (TE1-E1 jump, count CEL blinking)? Will this tell me anything? FSM says "normal operating temperature", does it work when cold?
7. Fuel Injection System: FSM has 90 pages of this! Lot of work. I'll start with IG section, then move to FI section. Starting with AFM test (good tip!).
I think if I do go through all this crap, I'll start understanding the ignition system like I now understand the block. Hopefully this can be accomplished in about 20 hours which I should be able to put in by end of day Sunday. Next week will be a KILLER to the checkbook, but next weekend I should have it running.
Depressing, but I'll put my head down and plow ahead. Hopefully I can get a buddy to right down test numbers to make it go quicker.
Go ahead and do test #4, get it out of the way its by far the easiest and fastest and you could always use your old distributor, cap and rotor.. I did not find if you re installed again your dist.,
(DID you take it aout again and went to DTC, then alligned mark on dist with mark on block?) not that you need to I just want to know what can remove from the list of possibilities. (but feel free to do this too! Its just too eaasy) just to start anew.
Make sure you test the cap with wires attaches, use a meter and test resistance from end end of wires to contact INSIDE the distributor. and make sure the center coil input ball/spring part is working well... This is more than likely NOT your problem, but yould you feel shame if it was...
most of the necesary steps to diagnose the IGN system have already been posted. But dont worry there are a lot of members willing to help.
SO go ahead and follow the FSM produres or the ones posted here and report back with detailed findings, it should be somthing simple, hopefully its not the igniter...
The PDF provided here should contain all steps to verify IGNITER.. Follow ALL steps DO NOT skip any, if unsure how to proceed on any test, stop and ask. We need to collect all info here!
(DID you take it aout again and went to DTC, then alligned mark on dist with mark on block?) not that you need to I just want to know what can remove from the list of possibilities. (but feel free to do this too! Its just too eaasy) just to start anew.
Make sure you test the cap with wires attaches, use a meter and test resistance from end end of wires to contact INSIDE the distributor. and make sure the center coil input ball/spring part is working well... This is more than likely NOT your problem, but yould you feel shame if it was...
most of the necesary steps to diagnose the IGN system have already been posted. But dont worry there are a lot of members willing to help.
SO go ahead and follow the FSM produres or the ones posted here and report back with detailed findings, it should be somthing simple, hopefully its not the igniter...
The PDF provided here should contain all steps to verify IGNITER.. Follow ALL steps DO NOT skip any, if unsure how to proceed on any test, stop and ask. We need to collect all info here!
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Are you sure the timing light is working? You might want to install a plug into one of the plug wires, ground the plug, and crank while visually checking for spark.
