| Author |
Message |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5164
Registered: 8-2002
| | Posted on Saturday, June 07, 2003 - 3:58 pm: | |
Eldon and I rewired the whole unit and the problem was isolated to a bad box. Replacement will be here monday. Voltage is now 12 volts.
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Mike Procopio (Pupz308)
Member
Username: Pupz308
Post Number: 387
Registered: 10-2002
| | Posted on Saturday, June 07, 2003 - 10:44 am: | |
Matt! I don't believe your coils where designed to run at 9 volts! (I could be wrong)--but coils step up 12 volts to on the order of 30k volts, which are jammed to the spark plugs...
I don't know what the behavior would be if the coils were getting a low voltage condition...
I would research this more. I think the coils usually get their current straight from the battery. If you tested the battery, and you're getting 12 volts, and you tested the voltage at the coils, and are getting 9--something isn't right.
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JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 234
Registered: 1-2002
| | Posted on Friday, June 06, 2003 - 11:34 pm: | |
Matt, if the ign boxes get too hot then you need more in line resistance. Also you should be getting close to 12 volts at the coils |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5162
Registered: 8-2002
| | Posted on Friday, June 06, 2003 - 11:26 pm: | |
Not enought voltage to the coils? it's getting 9 volts.
Does low voltage cause electrical to over heat? |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5159
Registered: 8-2002
| | Posted on Friday, June 06, 2003 - 7:57 pm: | |
O.k.
Shut down twice but now the slow down 5-8 light comes on......
Suggestions from the experts? |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5152
Registered: 8-2002
| | Posted on Friday, June 06, 2003 - 10:44 am: | |
Carl,
4-5
If is was the internals, Would not this problem occur at all times? Would turning the engine off and then back on correct the problem?
Coils are new but I am not sure if they can handle the higher voltage the cranes put out.
6
Ground wire is going to the base of the coil mounts.
What I don't get it that is ran fine for a month. Bank shut off 3 times yesterday. I turned off and then back on the engine and it's good.
No problems today.
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"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5151
Registered: 8-2002
| | Posted on Friday, June 06, 2003 - 10:39 am: | |
Mike,
Matt,
Just curious--did they check the current output at the battery and at the alternator?
Battery
They'll need some real equipment to handle the 50+ amps you'd expect (not a radioshack voltmeter, right).
We have a mechanic shop on site. He used a pretty heffty reader. |
Mike Procopio (Pupz308)
Member
Username: Pupz308
Post Number: 385
Registered: 10-2002
| | Posted on Friday, June 06, 2003 - 10:33 am: | |
Matt,
Just curious--did they check the current output at the battery and at the alternator?
They'll need some real equipment to handle the 50+ amps you'd expect (not a radioshack voltmeter, right).
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billy bob (Fatbillybob)
Member
Username: Fatbillybob
Post Number: 282
Registered: 8-2002
| | Posted on Friday, June 06, 2003 - 9:52 am: | |
could be all kinds of problems. 1) bad crane boxes. swap them see if problem goes to other side. 2) swap coils see if problem goes to other side 3) plug wires main coil wires swap to see if problem moves 4) internals of master distributor. on crane setup I have seen the light rotor nick and hit optical pick-up wires under use and mess up the signals. These rotors are usually set up as a 4 slot rotor with two crane pickups in there so there are lots of wires. I'm used to pre crane ownership and the rotors where not really concentric. So they could hit other parts in the distributor under use. 5) bad distributor bushings make vibration that can upset crane sensors 6) ground of xr700 to car body. that's all I can think of right now. Also Ferrari bk3a coils work fine. |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5147
Registered: 8-2002
| | Posted on Friday, June 06, 2003 - 9:01 am: | |
Mike,
We put a meter on it and the Alt and the Voltage Regulator are fine.
Back to Coils? or a bad box? |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5143
Registered: 8-2002
| | Posted on Friday, June 06, 2003 - 8:12 am: | |
Mike,
My alt is the original, unrebuilt one. I will have them check it this morning. You got my brain spinning. Thinking about it now, the Boxes get too hot to touch, Heat is caused by high voltage, voltage is caused by......the Alt.
M |
Mike Procopio (Pupz308)
Member
Username: Pupz308
Post Number: 380
Registered: 10-2002
| | Posted on Friday, June 06, 2003 - 2:45 am: | |
Matt,
Tell me about your alternator. Have you had it rebuilt?
After identical failures in the coils--one by me and one by po, 3000mi apart--and then finally an alternator failure (and rebuild)--I suspect my intermittently-failing, wildly-voltage-fluctuating alternator output as a possible cause...
Just something to consider.
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Andy Falsetta (Tuttebenne)
Junior Member
Username: Tuttebenne
Post Number: 169
Registered: 3-2003
| | Posted on Thursday, June 05, 2003 - 10:28 pm: | |
I've seen many OEM systems fail when hot only to start working (for a short period of time before total failure) after they cool down. These units are usually potted and aren't able to be diagnosed. There is probably a switching device inside thats going "open". Why not try heating up the Crane units with a hair dryer to see if you can make it fail. If it doesn't, move to the other and do the same thing. |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5142
Registered: 8-2002
| | Posted on Thursday, June 05, 2003 - 10:03 pm: | |
John,
"Matt, did you hook up the resistors to the system? " Yes
Andy
"I believe its the Crane units not the coils. This is a classic failure symptom of an electronic ignition."
Can you tell me more? Do they go bad? They are only about a month old.
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JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 232
Registered: 1-2002
| | Posted on Thursday, June 05, 2003 - 9:46 pm: | |
Matt, did you hook up the resistors to the system?
If you didn't then run the car for a while and then feel the ign. modules to see if they are hot. If they are, then you need to hook up resistors. |
Andy Falsetta (Tuttebenne)
Junior Member
Username: Tuttebenne
Post Number: 161
Registered: 3-2003
| | Posted on Thursday, June 05, 2003 - 9:13 pm: | |
I believe its the Crane units not the coils. This is a classic failure symptom of an electronic ignition. I would return them both and make it Crane's problem - let them figure out which one is bad. |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1454
Registered: 4-2002
| | Posted on Thursday, June 05, 2003 - 7:52 pm: | |
Uh, Raymond, there is no TDC in the older cars. They just use good old fashioned distributor(s), as found in nearly all cars for the 1/2 century up until the late 70's/early 80's. |
Raymond A. Castelhano (Oglmlw)
New member
Username: Oglmlw
Post Number: 23
Registered: 5-2003
| | Posted on Thursday, June 05, 2003 - 7:32 pm: | |
Hi Don,
First I think that the TDC sensor mentioned is the device that recognizes Top Dead Center which is the timing system's Starting Point. If it is not there, or not right, the system cannot work.
I have two sugestions;
1, Check fuses for looseness as well as other connectors.
2, Insure that you have a perfect ground from both distributors to the battery negative terminal when the problem is evident. Use good ohm meter (multimeter resistance scale on x1 if not digital) and measure directly to the battery.
MrC |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5141
Registered: 8-2002
| | Posted on Thursday, June 05, 2003 - 7:22 pm: | |
"Also make sure oil residue from a dist. seal leak didn't get on the optical sensor. "
I think if this was the case it would be constant and it would not "fix itself" once the engine is power cycled off then on
I am thinking that the crane unit is putting out more voltage then the accel coils can handle and they overheat and are cutting off.
I am going to change them and see if the same occures. |
Greg Rodgers (Joechristmas)
Member
Username: Joechristmas
Post Number: 755
Registered: 3-2001
| | Posted on Thursday, June 05, 2003 - 7:13 pm: | |
I use PS20 coils. They seem to work well. Also see if the red led indicators are working on both units. I have heard of issues with optical sensors before even after a few weeks of ownership. Also make sure oil residue from a dist. seal leak didn't get on the optical sensor. |
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 920
Registered: 5-2001
| | Posted on Thursday, June 05, 2003 - 7:08 pm: | |
Carb cars do not have TDC sensors... |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5140
Registered: 8-2002
| | Posted on Thursday, June 05, 2003 - 7:07 pm: | |
Dave,
It only did it twice and one I shut off the car and let it cool for a couple of minutes it runs perfect again. Every looked good on the inside.
Mike,
Whats a TDC? I do not think my carb car has one. I have not heard of them before.
M |
mike 308 (Concorde)
Junior Member
Username: Concorde
Post Number: 221
Registered: 8-2002
| | Posted on Thursday, June 05, 2003 - 6:59 pm: | |
Could be one of your tdc cam sensors has crapped out. Easy fix (for the mechanic, cheap for me)... that was the problem on my308QV several years ago when I lost one bank. |
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 915
Registered: 5-2001
| | Posted on Thursday, June 05, 2003 - 5:09 pm: | |
have you checked the "trigger wheel" and the related parts in the distributors? Maybe something is a bit loose or changing dimensions slightly at high rpms? |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5135
Registered: 8-2002
| | Posted on Thursday, June 05, 2003 - 5:07 pm: | |
Dave,
I checked all connections and everything is tight.
When I drive around town, under 4k rpm and no hot dogging, it fine. When I hit redline and gun it, right after at say, a stop light. It drops the bank. I turn the car off, wait a minute and it fires back up.
Overheating coil? |
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 912
Registered: 5-2001
| | Posted on Thursday, June 05, 2003 - 4:45 pm: | |
Matt,
I would go through and check all your connections related to the ignition in the engine compartment. Pay close attention to the Molex connectors for the Crane boxes. At least I think there are some. I have had trouble with those on other devices, so worth a look. Make sure none of the pins are backing out, and that all the crimps are tight. Same with all the other connections, make sure they are tight, and no breaks anywhere. If you have some Stabilant 22A, brush some on the pins of those Molex connectors too. I wonder if one of your Crane boxes is acting up. Figure out which bank is cutting out, and swap the boxes.... |
"The Don" (Mlemus)
Senior Member
Username: Mlemus
Post Number: 5134
Registered: 8-2002
| | Posted on Thursday, June 05, 2003 - 4:16 pm: | |
I just need confirmation on this.
4 weeks ago I changed out the points to the crane xr700
Once the units were installed. I would loose a bank.
I changed the coils out and replaced the stock MM with Accel 8140's. Drove fine in 100 degree days and XXX mph.
It ran like a champ but today on a cool temp day, It happened again. I lost a bank. I would shut the car off. Wait a minute and it would fire up again.
I am going to replace the coils (again) but with the crane PS20 coils.
Should I look at something else?
It is heat related from what I can tell
Matt |