mystery start problem
03-09-2011, 07:11 PM
#1
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mystery start problem
So my car, 84 944na, took a ride on a trailer from cali to TX. The first two days off the trailer it started normally. Drove fine. Then it sat for a week. Nothing unusual happened. Just sitting in the driveway.
I went to start it and it just didnt want to start...then it stumble fired as I was releasing the key from the starting position. It did this twice then fired up..
I drove the car 150 ft from the front drive around back. This whole time the battery light was on.....I thought it may have been drained because I forgot to unplug the phone charger from the lighter....so I revved the engine for a minute..the battery light started to flicker then it shut off. I ran it another minute then I got out to check under the hood.
I revved the engine by hand under the hood...twice...then a moment later it started to sound like it was under idling so I reached again to give it some gas but she stalled.
Now Im in NO START. Im at my aunts in Houston so I have minimal tools available....but Ive
1. jumpered the dme relay to hear the fuel pump (CHECK)
2. swapped the dme relay to my spare (NO CHANGE)
3. swapped the DME (I keep a spare in the car NO CHANGE)
Im wondering if it might not be a bad ignition switch....I have to turn the key to its most extreme rotation to get the starter engaged...and the car seems to "catch" for a moment as if its just then trying to start as I release the key from attempting to start.....
Ive been out of work since thanksgiving and I start a new job in a week and a half....THIS IS NOT THE TIME
ANY advice or help would be appreciated. Obviously I should check for spark...I need to wait for a second set of hands to get home to do that....and Im impatiently brainstorming in the meantime.
I went to start it and it just didnt want to start...then it stumble fired as I was releasing the key from the starting position. It did this twice then fired up..
I drove the car 150 ft from the front drive around back. This whole time the battery light was on.....I thought it may have been drained because I forgot to unplug the phone charger from the lighter....so I revved the engine for a minute..the battery light started to flicker then it shut off. I ran it another minute then I got out to check under the hood.
I revved the engine by hand under the hood...twice...then a moment later it started to sound like it was under idling so I reached again to give it some gas but she stalled.
Now Im in NO START. Im at my aunts in Houston so I have minimal tools available....but Ive
1. jumpered the dme relay to hear the fuel pump (CHECK)
2. swapped the dme relay to my spare (NO CHANGE)
3. swapped the DME (I keep a spare in the car NO CHANGE)
Im wondering if it might not be a bad ignition switch....I have to turn the key to its most extreme rotation to get the starter engaged...and the car seems to "catch" for a moment as if its just then trying to start as I release the key from attempting to start.....
Ive been out of work since thanksgiving and I start a new job in a week and a half....THIS IS NOT THE TIME
ANY advice or help would be appreciated. Obviously I should check for spark...I need to wait for a second set of hands to get home to do that....and Im impatiently brainstorming in the meantime.
Last edited by techartisan; 03-09-2011 at 08:12 PM.
03-10-2011, 04:38 PM
#2
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SOLVED....
This morning I couldnt get any sound from the pump when jumpered... Yesterday the fuel pump ran jumpered.....but I suspected the FP wasnt running during startup...even when jumpered....SO I decided to try directly powering the pump....and found the problem before I got that far...
PO used crimp connectors when he replaced the fuel pump.....The ground wire was barely connected...when I touched it the pump started (jumper still in place) in fact shaking the rear end allowed it to stutter on and off.....so I disconnected the battery....changed out the connector...
Once I fixed the ground and charged my battery back up she fired right up. I let her run for 15 min or so then killed and restarted a few times to make certain......
Looks like I lucked out this time.
This morning I couldnt get any sound from the pump when jumpered... Yesterday the fuel pump ran jumpered.....but I suspected the FP wasnt running during startup...even when jumpered....SO I decided to try directly powering the pump....and found the problem before I got that far...
PO used crimp connectors when he replaced the fuel pump.....The ground wire was barely connected...when I touched it the pump started (jumper still in place) in fact shaking the rear end allowed it to stutter on and off.....so I disconnected the battery....changed out the connector...
Once I fixed the ground and charged my battery back up she fired right up. I let her run for 15 min or so then killed and restarted a few times to make certain......
Looks like I lucked out this time.
03-14-2011, 07:15 PM
#4
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well congratulations seem to have been premature. While the bad ground to the pump couldnt have helped my car....the problems back.
Started it several time with no problems...
then yesterday morning when started the battery light stayed on for a solid minute and a half before flickering out.
Did not reappear on restart....multiple successful restarts.
this morning...
again battery light kicks remains on...flickers a bit while revving gas...abruptly shut off at 4k
Ran engine for a few minutes.
FAILED TO RESTART
turn the key...starter kicks in.
engine turns over...endlessly.
release key.
as the momentum of the engine turning winds down....
something catches and it sounds like its trying to "fire up"
careful timing of key release and application of gas will cause a stumble to propagate.
With luck this stumble can be coaxed into a full running engine with no discernible difference from its normal operation. No unusual idling. Revs fine. Has its usual return to idle stumble but no more then normal. Seems to run fine....issue only in startup.
Battery Light not illuminated when running.
Battery cables removed while engine running.....NO STALL.
My car is an 84 na
No Factory Alarm so I dont think its the exciter wire issue.
Horn does not actuate manually HOWEVER Horn randomly beeps, once a month or every other month while starting. I mention this as I think the ignition switch could possibly be the issue....I havent torn the column down yet but this shorting seemed relevant.
Ive used 2 different DME's and DME relays attempting to start and there is no change in the cars behavior so I assume they can be ruled out.
Right now my ideas of what could be wrong are going in several directions at once. I havent time funds nor tools to chase all the gremlins at once so if anyone has ideas to share Ive open ears.
Thanks in advance
Started it several time with no problems...
then yesterday morning when started the battery light stayed on for a solid minute and a half before flickering out.
Did not reappear on restart....multiple successful restarts.
this morning...
again battery light kicks remains on...flickers a bit while revving gas...abruptly shut off at 4k
Ran engine for a few minutes.
FAILED TO RESTART
turn the key...starter kicks in.
engine turns over...endlessly.
release key.
as the momentum of the engine turning winds down....
something catches and it sounds like its trying to "fire up"
careful timing of key release and application of gas will cause a stumble to propagate.
With luck this stumble can be coaxed into a full running engine with no discernible difference from its normal operation. No unusual idling. Revs fine. Has its usual return to idle stumble but no more then normal. Seems to run fine....issue only in startup.
Battery Light not illuminated when running.
Battery cables removed while engine running.....NO STALL.
My car is an 84 na
No Factory Alarm so I dont think its the exciter wire issue.
Horn does not actuate manually HOWEVER Horn randomly beeps, once a month or every other month while starting. I mention this as I think the ignition switch could possibly be the issue....I havent torn the column down yet but this shorting seemed relevant.
Ive used 2 different DME's and DME relays attempting to start and there is no change in the cars behavior so I assume they can be ruled out.
Right now my ideas of what could be wrong are going in several directions at once. I havent time funds nor tools to chase all the gremlins at once so if anyone has ideas to share Ive open ears.
Thanks in advance
03-14-2011, 07:50 PM
#5
Take the battery to the auto parts store and have it checked and charged if necessary.
Check the battery voltage with the engine off, it should be between 12 and 12.5 VDC if the battery is charged. Check the ground cables from the negative battery terminal to the chassis and the engine block.
Check the connection at the starter where the 2 heavy leads are tied together.
Check the battery voltage while the car is running it should be between 13 and 14 VDC if the alternator is working.
Check the battery voltage with the engine off, it should be between 12 and 12.5 VDC if the battery is charged. Check the ground cables from the negative battery terminal to the chassis and the engine block.
Check the connection at the starter where the 2 heavy leads are tied together.
Check the battery voltage while the car is running it should be between 13 and 14 VDC if the alternator is working.
03-14-2011, 09:53 PM
#6
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Car started normally first try...
Sitting voltage 12.88
Running voltage 13.9
Voltage at cables running no battery 14.6
Battery no cables 12.85 (drop due to cable removal immediately after starting)
I didn't check the starter wiring, the starter is engaging fine, engines turning.....its either not getting fuel...or spark till I let off the starter...when this issue isn't hiding from me LOL
Its too dark to check the starter wiring now....could the starter be drawing enough power to prevent ignition??? I'm more prone to believe its ignition wiring but ill gladly take advice to the contrary.
I picked up a 24mm...tomorrow I'm planning to check the column wiring.
Please keep the advice coming....
Sitting voltage 12.88
Running voltage 13.9
Voltage at cables running no battery 14.6
Battery no cables 12.85 (drop due to cable removal immediately after starting)
I didn't check the starter wiring, the starter is engaging fine, engines turning.....its either not getting fuel...or spark till I let off the starter...when this issue isn't hiding from me LOL
Its too dark to check the starter wiring now....could the starter be drawing enough power to prevent ignition??? I'm more prone to believe its ignition wiring but ill gladly take advice to the contrary.
I picked up a 24mm...tomorrow I'm planning to check the column wiring.
Please keep the advice coming....
03-14-2011, 10:17 PM
#7
Check the battery voltage while starting the engine and post the results.
Have you check the ground cables from the negative battery terminal to the chassis and the engine block?
Have you had the battery load tested at the auto parts store?
Starter drawing to much current ?
Ignition switch? maybe
Have you check the ground cables from the negative battery terminal to the chassis and the engine block?
Have you had the battery load tested at the auto parts store?
Starter drawing to much current ?
Ignition switch? maybe
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03-14-2011, 10:35 PM
#8
Racer
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Haven't the ability to move the car today...I'm boxed in.
Voltage during start 11.49
Car started without issue 3 times in a row.
I wish it would screw up consistantly then at least id know I was getting a representative result
Voltage during start 11.49
Car started without issue 3 times in a row.
I wish it would screw up consistantly
then at least id know I was getting a representative result
03-15-2011, 12:06 AM
#10
Rennlist Member
Don't do that!! Alternators can go wild with no battery connected.
03-15-2011, 12:27 AM
#11
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Could be...but then the question is why?
This increases my suspicion of ignition switch/wiring issue...my daughter remembered that not only do we have the "phantom horn" but several times in the past weeks my door alert sounded with the key removed....to which I've had to put the key back in turn a bit and remove again....to stop the beeping....
If I understand correctly this would allow power to the window motors etc potentially draining the battery...
So I guess tomorrow ill tear into the column
This increases my suspicion of ignition switch/wiring issue...my daughter remembered that not only do we have the "phantom horn" but several times in the past weeks my door alert sounded with the key removed....to which I've had to put the key back in turn a bit and remove again....to stop the beeping....
If I understand correctly this would allow power to the window motors etc potentially draining the battery...
So I guess tomorrow ill tear into the column
03-15-2011, 12:41 AM
#12
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Never heard that one before....
When my last car (non porsche) kept killing the battery, disconecting the battery would kill the engine....dead alternator....seemed like a smart test.
For the record, this cars alternator maintained a steady reading without the battery connected. It was only ran 30 sec or so disconnected so I'm relatively sure I did no harm....
The only risk I could percive would be in the event of a sudden increase in system draw....the only chance of that I can think of would be the fans...a non issue for me as they are manually switched.
Id be quite interested in an explanation of the risk or issues associated with this....if my understanding is flawed.
When my last car (non porsche) kept killing the battery, disconecting the battery would kill the engine....dead alternator....seemed like a smart test.
For the record, this cars alternator maintained a steady reading without the battery connected. It was only ran 30 sec or so disconnected so I'm relatively sure I did no harm....
The only risk I could percive would be in the event of a sudden increase in system draw....the only chance of that I can think of would be the fans...a non issue for me as they are manually switched.
Id be quite interested in an explanation of the risk or issues associated with this....if my understanding is flawed.
03-15-2011, 12:49 AM
#13
Nordschleife Master
OK, next time it is running, jiggle the hell out of your coil wire, spark plug wires (if one of them shocks you, you have found the culprit!), then remove and check the inside of your cap for black lines (carbon traces)..
Your other post makes me suspect the ignition switch...
switch could be causing your battery drain, and no start, no start could also be caused by bad cables or carbon fouling of your cap!
Your other post makes me suspect the ignition switch...
switch could be causing your battery drain, and no start, no start could also be caused by bad cables or carbon fouling of your cap!
03-15-2011, 10:28 AM
#14
Rennlist Member
Never heard that one before....
When my last car (non porsche) kept killing the battery, disconecting the battery would kill the engine....dead alternator....seemed like a smart test.
For the record, this cars alternator maintained a steady reading without the battery connected. It was only ran 30 sec or so disconnected so I'm relatively sure I did no harm....
The only risk I could percive would be in the event of a sudden increase in system draw....the only chance of that I can think of would be the fans...a non issue for me as they are manually switched.
Id be quite interested in an explanation of the risk or issues associated with this....if my understanding is flawed.
When my last car (non porsche) kept killing the battery, disconecting the battery would kill the engine....dead alternator....seemed like a smart test.
For the record, this cars alternator maintained a steady reading without the battery connected. It was only ran 30 sec or so disconnected so I'm relatively sure I did no harm....
The only risk I could percive would be in the event of a sudden increase in system draw....the only chance of that I can think of would be the fans...a non issue for me as they are manually switched.
Id be quite interested in an explanation of the risk or issues associated with this....if my understanding is flawed.
Read Step 2 here: http://www.wikihow.com/Check-an-Alternator
http://www.autozone.com/autozone/rep...00c1528004e9ac
03-15-2011, 01:02 PM
#15
The summary of the risk associated removal of the battery lead while the engine is running is that the DME /ECU computer can be damaged due to excessive voltage, the alternator regulator design assumes that a functional battery is connected to the alternator output.
The proper way to check the Alternator while installed in the car is to use the Dash volt meter or a multi-meter to verify the output voltage of alternator. Starting the engine many times in in secession with out letting the battery charge recover, could drain the battery and possible cause a no start condition.
The proper way to check the Alternator while installed in the car is to use the Dash volt meter or a multi-meter to verify the output voltage of alternator. Starting the engine many times in in secession with out letting the battery charge recover, could drain the battery and possible cause a no start condition.