starter problem- again- lost- please help
 

I have had an intermittent starter problem that has me at wits end. One main problem is my mechanic is 55miles away- it usually is a flatbed tow to get the car too him as I can't take a day off work. The car is an 85 row carrera- that has been very reliable for the last 3 years.
The problem is very intermittently you turn the key- and no starter- fuel pump runs- but no starter at all. First time was about a year ago- flatbedded car to mechanic- when it got there it worked fine. He went through everything- checked the ignition switch, no power loss through the wire loom, starter ok, battery ok, etc. So $700 later I get the car back and it works for 8months- then same thing. This time I tapped the solenoid with a hammer- and it worked for 4 more months. The third time it happened I tapped the solenoid again- it started up- and I took it to the mechanic. When the car got there it would not start. He put in a new starter- same problem. He tried a 3rd starter- same thing. The battery measured a little low- so he tried jumping the car - and the starter worked fine. We didn't know what to do- so I left the new starter-which is a rebuilt stock starter- in, and put in a new battery. Car ran fine for 2 weeks- now same thing again. Where do I go from here? I have power to the starter, a new battery, a new starter, the ignition switch was just checked. I am considering adding one of those relays that bypass some of the wiring to the solenoid- but I don't like bandaid repairs. I would appreciate any ideas on what to do next- besides set the car on fire, or always park on a hill so I can push start it. Is there a way I can jump power to the small solenoid lead to see if that is the problem?? The basic stuff, like the ground strap on the transmission is ok.
Thanks
gary

Hi jchappel,

I had the same problem with the same symptoms. I replace the starter twice (with non Bosch), did not fix the problem. My wrench said the problem is common and the fix is simply to replace the starter with a new Bosch. I said go ahead what I did wasnt working. He put a new Bosch in and the problem is solved. I have heard that the HiTorque starters work as well, but have no experience with those.

Hope this helps.

One new fact:
Voltage from battery- 12.9V
Voltage at main lead at starter-12.9V
Voltage at "solenoid" lead when the key is turned to start postion-9.4V
I assume this type of voltage drop is my problem. I know the loss could be at the ignition switch, or loss along the wire. Any thoughts- or is the relay addition the easy fix here?? How do I proceed from here?
Can I safely run a jumper from the main lead at the starter to the solenoid lug just to test my idea- or will that short something out??

Thanks again
Gary

Gary:

You can bridge the Battery lead to the solenoid without harming anything (that is how remote starter switches work). removed the DME relay and tap it gently with the butt end of a screw driver, and replace.

Also check the ground strap from the trany to the chassis.

Good luck, electrical gremlins are the pits.:mad:

I had the same problem, change out a few things but found through trial and error that it was the alternator. Get the car started and check the voltage at the battery. It should be above, if I remember right above 14 volts. If not then either the alt is not working right or you got a big draw. With me the alt would work sometimes so the battery would be charged enough to run but then a few weeks later the alt wouldn't charge and the battery would run down enough so that it wouldn't start. The fuel pump, lights and everything else would work but no starter. You need the full 12+ volts to start it. I hope this helps.

OK, continued work in progress.
I ran a wire from the hot lead at the starter to the solenoid lead- nothing.
I then ran a jumper cable from the positive of my battery, back to the starter- car started right up. Now it works normally- gosh I hate these intermittent gremlins. Does this sound like I need to run a new power cable to the starter- don't know how hard that would be to do- or would the starter relay help with this?????
Thanks again, I am kind of at wits end.
Gary

Here's a thought straight out of left field (which is appropriate considering that the World Series starts in about an hour) -- Is it possible you have a problem with the starter switch?

Gary...9.4V doesn't read too good..in fact it's bad..so, you gotta fix that voltage drop...sorry, can't say what's happening because you got a start from a direct feed from bat to starter..maybe 2 problems..if it was my problem I would install a temporary sol jump from starter using a relay..trigger relay only when a problem..and check voltage drop at bat positive and starter when cranking eng with ignition disconnected........Ron

I cleared up my intermittent starter problems by cleaning the 14 pin connector in the engine compartment. Clean, spread the male terminals with a single edge razor blade and coat with dielectric silicone. Good luck.

rstolll- where is the connector??


Is there a lead anywhere in the rear of the car/engine compartment where I can pick up an additional high current lead to go to the starter, or do I need to pull a line from the battery itself? Any ideas on how to pull the line from the battery- sorry to sound so dumb, but I am- do I run the lead under the car, in the tunnel, or what? The wiring will be easy, but pulling an additional lead looks like a difficult project unless I just run it under the car.
Thanks again.
Gary

Gary..there is a bunch of connectors from the starter switch to starter sol...the yellow wire has a connection in the under dash area of luggage compartment on driver side..if you have a starter disable on an alarm system chances are the disable relay has a smaller diameter feed wire to the yellow sol feed/may be contributing to problem along with this relay..in your engine comp on the driver side close to the electrical panel is the 14 pin connector..and I shouldn't forget the electrical part of the ignition switch, which I believe should be changed at 100k miles/neurotically speaking, if only for preventive maintance..I would still connect a temporary 30 amp relay to starter to get the car back on the road and spend hours cleaning up things later..and the issue with a battery jumper cable to starter that you did for a start..the battery positive connector is a possibility along with the 2 smaller red feed wires/the connection is not bulletproof...of course you cleaned the chassis ground foreward of the battery and the tranny to chassis ground.........Ron

It is located on the back of the relay/fuse block on drivers side of engine compartment wall. Clean the plug, no rewiring necessary.

btw, also fixed my jumpy oil pressure guage by tightening/cleaning connection at sending unit. I like those easy repairs. ;)

I don't want to step on any toes here.....seeing as this is my first post as a technicial issue. If we know the solenoid is getting only 9.4 volts, then obviously the problem is somewhere between the Pos. post at the battery and the start wire at the solenoid ( given that the starter has a good clean ground) Using a voltmeter, put the black wire on the POS post and the red wire on the start wire wire at the solenoid. With the key in the start position the meter should be less than .4 volts anything above that indicates that the system has a weak connection and or weak wire. The next test is very simple and works on any circuit. Going backwards from the solenoid connect the red wire to the other end of the start wire and check for a voltage drop. Continue on through the system ( backwards ) until you have LESS than .4 volts and there is the problem area. Also do the same test on the ground side at the starter. Just remember........the circuit HAS TO HAVE AN APPLIED LOAD!!!!! As in, if working with the headlamp circuit......turn the headlamps on!!!!!! As a hint........correct voltage through the ign switch has been a problem on every make and model vehicle out there!!!!!

I'm with Chad on this one..............Ron

Thanks, I'll start through the system with this in mind. Does anyone know where all I need to check? I believe there is a connection at the 14pin plug in the engine compartment, there is of coarse the connection at the ignition switch itself, and I believe a connection in the trunk, or luggage compartment- any other places to check?
Does the wire stay yellow throughout the car?- I can find it with a continuity checker- but color would be easier?
I will also add an additional ground strap to the starter- and hopefully I will have my reliable everyday driver back again
thanks- this board is great
Gary

Can anyone send me the starter circuit wiring for the car in question ...I would LOVE to help!


I'm a little lost on this whole idea of adding a SECOND ground. Over the years I've learned several important phrases most have heard
The wheel will always be round.
If it ain't broke.........you know the rest !!!! and
Do like the military does, if it ain't broke fix it untill it is!!!!

My point is why not just do the voltage drop test on the system and find the actual problem. If you have no voltage drop on the ground side than a second ground will give you the exact same reading.
Man...I'm not chewing on ya .....I just hate to see a fellar work up a headache on a problem that's very rewarding to you when the problem is found. Current flow is like water.. If you install a dam in the system, it may not stop all of the water but is sure as hell slows it down!!!!! HHHMMMMM....almost like a bad connection!!!!!!
PS: I only use ONE toothbrush....it works just fine SmileWavy

[QUOTE]Originally posted by Chad Ruwe
[B]Can anyone send me the starter circuit wiring for the car in question ...I would LOVE to help!


I'm a little lost on this whole idea of adding a SECOND ground


Chad...I'm sorry for any confusion on the 2nd ground..it's not generally necessary..not many do a 2nd ground..I have added a 2nd ground because I want a back-up to the stock ground..I do BigBig Rides in the 911, and IMO the 911 electrical system leaves much room for improvement. wait till you want to install real high watt headlights into a stock 911 headlight system..I can't be trouble shooting an electrical system weakness in the remote areas I travel to..and you may be correct "if it ain't broke", but I don't have that luxury..and for reference, Early S Man has the most logical approach to 911 electrical systems/ not me ..
Pelican has wiring diagrams somewhere on this web..........Ron

Here's a circuit from this site. You'll need to access page 1 and 2 for the starter circuit.

http://www.pelicanparts.com/911/911_Parts/Electrical/911_electrical_82SC_Part1-1.jpg

Ahem. Any car that is the age of our cars could use a thorough cleaning of all electrical contacts and connections. Electrical gremlins are caused by dirty connections more often than all other causes combined, I think. That 9.6 volts thing is almost certainly being caused by corrosion somewhere. Every chance you get, unplug connections, wire brush them, apply a tiny bit of silicon grease and reconnect.

Had exactly the same problem myself couple of wks ago. Cleaned every terminal, all grounds and also the starter mounting points. Fired up better than it ever had right after this. Pay particular attention to the solenoid + post & the + feed ring termination. A useful doc I used for troubleshooting:

http://www.type-911.co.uk/images/general/text/Starter%20System%20Troubleshooting.htm

Hope this helps.

[b/"..Voltage from battery- 12.9V
Voltage at main lead at starter-12.9V
Voltage at "solenoid" lead when the key is turned to start postion-9.4V..."[/b]

Gary,
Based on your test numbers, you may or may not have an electrical problem. The starter solenoid is but one "load" on the branch circuit. There is also the starter motor that is (should be) running every time the solenoid is energized. Thus, if you checked the voltage at the solenoid lead when cranking, the 9.4 volts you read is the normal available voltage from the battery during cranking. This is because the starter is placing a large load on the battery. BTW, the battery is fine if above 9 volts while cranking.

If, however, you checked the available voltage at the solenoid lead while cranking and the starter motor remains idle (there is no voltage drop from the starter), then there indeed is a voltage drop in the solenoid circuit, enough to prevent the solenoid from energizing. However, one can't normally isolate the solenoid circuit unless you disconnect the battery cable from the starter and insulate it or physically remove it from the starter, then test.

I'd suggest verifying the ground cable(s) and all electrical connections are okay as others have suggested. Check for voltage drop throughout the circuit, not just up to the load (multiple grounds are fine). I can't imagine all the different starters you've tried all had faulty solenoids. How about trying this? Connect a remote starter switch to the solenoid and crank the engine using this temporary switch; one jumper clamped on the solenoid terminal, the other on the battery cable on the starter motor. If the motor consistently works with this setup, you know the problem is somewhere in the solenoid control circuit (a solenoid is basically a large relay with a mechanical plunger).

Does the starter freeze up all the time or just when the engine is at operating temperature? A common affliction in later Porsches is engine heat that soaks into the starter motor; the armature grows in size due to the temp. increase and creates a lot of drag (actually rubbing) as it attempts to rotate; sometimes it won't rotate at all. The hammer trick some people use sometimes frees up the armature. Placing a wet shop towel on the hot motor or a spritz of water from a spray bottle may also help.

Hope this helps,
Sherwood Lee
http://members.rennlist.org/911pcars

Things get more interesting- or confusing. Sherwood- to connect the remote starter switch I just need to jump it between the hot lead on the starter from the battery to the yellow solenoid lead on the starter, correct?
Well.....
I cleaned off all the connections I could find- at the battery, at the 14pin connector in the engine compartment and at the starter-- no change- car no workee.
I then ran a set of jumper cables from the battery directly to the starter- car started fine. Disconnected the jumper cables- starter doesn't work. I did this several times. I then disconnected the ground- running just the pos lead from the battery directly to the starter- the starter worked fine, and didn't work when I disconnected it.
So, I thought I must have a bad cable from the battery to the starter- and just as I thought about it- the car started working normally. Right now it starts fine- and I didn't do anything or truely find the problem yet. Now when I start I get less than a 500mv drop from the battery pos terminal to the starter- so that lead has either fixed itself or I have some other problem. My present guess is that I have a bad connector on the starter cable from the battery- but they look ok, and nothing changes when I twist and pull on them.
I think I'll have to wait until it stops working again, and go at it some more. It is now working fine, and everything measures ok?
Maybe a halloween haunting.
These intermittent problems drive me crazy- as I never know when I can trust the car.
Thanks again for your help, has anyone heard of this thick cable going bad??
Thanks again for your help.
Gary

Gary,
It sounds like you isolated the main cable to the starter as the source of the malfunction. You now only have to look at two places; the ends of this cable. Sounds like a poor connection that's causing the intermittent starting.

Sherwood

Yes I did clean the grounds- but no change. When I used the jumper cables directly to the starter it also worked if I only used the positive jumper, but did not work if I only used the neg or ground jumper- so I am thus assuming the ground is not the issue.
The cable ends look ok- they are not loose or anything. Now that the starter is working- jiggling and moving the cable from the battery to the starter doesn't do anything- so I think I will have to wait for it to fail agian so I can look for voltage drops along the cable.
Thanks again for all your support
gary

Ron....point taken:rolleyes: