Intermittent Cranks but Doesn't Start - Alfa Romeo Bulletin Board & Forums
 1Likes
  • 1 Post By alfaparticle
 
LinkBack Thread Tools Display Modes
post #1 of 14 (permalink) Old 10-07-2019, 06:53 AM Thread Starter
Registered User
 
Scott in MN's Avatar
 
Join Date: Jan 2005
Location: St. Paul, MN
Posts: 362
Garage
Intermittent Cranks but Doesn't Start

The intermittent nature of this makes diagnosis difficult. Hopefully someone can shed a little light.

'83 GTV6. Car will start and run fine. Next time I try, it cranks and sounds like it wants to fire but does not. This can happen the same trip. I drive to the store and then won't start when time to leave. Sometimes it just has to sit awhile other times I pull a plug to check spark, find spark, put back together and it fires right up. Or I check distributor cap, and upon reassembly it starts.

I've replaced fuses, checked connections that I know of, and replaced cap and rotor.

I've read of the Hall Effect sensor in the distributor. Could this be a culprit? I believe mine to be the 2 wire variety. Here are a couple of pictures. Check out the wiring on the green wire plug.

Thank you
Scott in MN
Attached Images
   

____________________________________________
[I]Why don't you knock it off with them negative waves? Why don't you dig how beautiful it is out here? Why don't you say something righteous and hopeful for a change?[/I]

Last edited by Scott in MN; 10-08-2019 at 06:43 AM.
Scott in MN is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old 10-07-2019, 07:38 AM
Senior Member
Gold Subscriber
 
Join Date: Jun 2016
Location: Santa Barbara, CA
Posts: 238
In a perfect world you would use an oscilloscope to check the reluctor signal at the ignition control module, preferably while wiggling that connector and comparing the pattern in the start vs no start condition. Since most people do not own a scope, it would be difficult to directly check the reluctor output, but you can use a voltmeter and test light to check most of the ignition circuit.

Chris A: '81 GTV6 rescued from junkyard, "GT" car/'86 Porsche 944 Turbo track/street car/'73 BMW 2002tii fun street car/'74 Jensen Healey Lemons Rally car!
cda951 is offline  
post #3 of 14 (permalink) Old 10-08-2019, 06:53 AM Thread Starter
Registered User
 
Scott in MN's Avatar
 
Join Date: Jan 2005
Location: St. Paul, MN
Posts: 362
Garage
First, I apologize for my initial attempt at posting photos. I cleaned that mess up.

I now realize that my '83 has a 2 wire Variable Reluctance sensor and not a Hall Sensor. I'll detail the wires at the distributor sensor and the ignition control module.

____________________________________________
[I]Why don't you knock it off with them negative waves? Why don't you dig how beautiful it is out here? Why don't you say something righteous and hopeful for a change?[/I]
Scott in MN is offline  
Sponsored Links
Advertisement
 
post #4 of 14 (permalink) Old 10-08-2019, 07:46 PM
Senior Member
Gold Subscriber
 
Join Date: Jun 2016
Location: Santa Barbara, CA
Posts: 238
I just re-read your post. It is certainly possible that you have a vapor-lock issue when the engine is hot; an ignition issue is usually go or no go. You would need to connect a fuel pressure gauge to verify this. If the fuel pressure drops to zero quickly after engine shutoff, you have an issue with either the fuel pressure regulator, fuel pump check valve, or possibly fuel injectors/cold start injector leaking down. A huge cloud of fuel smoke out of the tailpipe after the engine does start would be a good indicator of leaking injectors.

As for ignition system testing:
If you have a good multimeter such as a Fluke and set it to read AC voltage, you might be able to get a flash of a signal at the distributor reluctor with the plug disconnected, then see if you get a similar thing to happen at the ignition control module. Not a super accurate test, but worth a try. A good test light will be able to catch the digital switching signal output from the ignition module to the coil negative terminal; again not as good as a scope, but no flashing equals nobody home.

A good digital timing light is also a good quick check of the secondary ignition circuit---clip the clamp around the coil secondary wire when you have a crank/no start condition, while the test light is also hooked up. Then you can isolate whether it is a problem with the primary ignition circuit, coil, or secondary ignition circuit. The original Bosch coils are incredibly durable, as are the ignition control modules, but either could overheat and drop out. Many cheaper modern replacement ignition coils (including the Brazilian-made Bosch ones) are complete junk and always a suspect in these conditions . . .

Chris A: '81 GTV6 rescued from junkyard, "GT" car/'86 Porsche 944 Turbo track/street car/'73 BMW 2002tii fun street car/'74 Jensen Healey Lemons Rally car!
cda951 is offline  
post #5 of 14 (permalink) Old 10-08-2019, 07:52 PM
Senior Member
Platinum Subscriber
 
alfaparticle's Avatar
 
Join Date: Oct 2004
Location: Columbia SC
Posts: 12,967
VR sensors are very robust. If there is a problem it is more likely in the connector or the associated wires. They are however dependent on a consistent gap to the rotor.

Ed Prytherch
79 Spider
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
alfaparticle is offline  
post #6 of 14 (permalink) Old 10-08-2019, 08:17 PM
Senior Member
Gold Subscriber
 
Join Date: Jun 2016
Location: Santa Barbara, CA
Posts: 238
Quote:
Originally Posted by alfaparticle View Post
VR sensors are very robust. If there is a problem it is more likely in the connector or the associated wires. They are however dependent on a consistent gap to the rotor.
Agreed, that type of distributor reluctor does not tend to fail (have not seen it myself). The connector certainly looks suspect, however .

The VR crankshaft and reference mark sensors as used in '80s Porsche 911, 944, BMW E30, etc with early Bosch Motronic fuel injection systems certainly do fail, but they live in a relatively harsh environment, and the adjustable sensor brackets lead to the opportunity of one setting the gap incorrectly.

Chris A: '81 GTV6 rescued from junkyard, "GT" car/'86 Porsche 944 Turbo track/street car/'73 BMW 2002tii fun street car/'74 Jensen Healey Lemons Rally car!
cda951 is offline  
post #7 of 14 (permalink) Old 10-08-2019, 10:57 PM
Registered User
 
Join Date: Feb 2010
Location: Newport Beach, CA and Melbourne, Aus.
Posts: 1,277
My experience, same symptoms exactly. Clogged fuel filter, I guess contributing to vapor locks / low fuel pressure. Whatever, after I replaced it never had another issue.

Only mentioning as no one ever seems to mention this as a possible cause / contributor.

Alister
1973 105 GTV (Alfa #6 of 19 owned)
Aggie57 is offline  
post #8 of 14 (permalink) Old 10-09-2019, 07:19 AM
Senior Member
Gold Subscriber
 
Join Date: Jun 2016
Location: Santa Barbara, CA
Posts: 238
Quote:
Originally Posted by Aggie57 View Post
My experience, same symptoms exactly. Clogged fuel filter, I guess contributing to vapor locks / low fuel pressure. Whatever, after I replaced it never had another issue.

Only mentioning as no one ever seems to mention this as a possible cause / contributor.
Interesting. A clogged fuel filter usually causes issues at higher load when the engine demands a greater volume of fuel, but I would never talk anyone out of replacing it. Did you do any other fuel system work at the same time as the fuel filter replacement?

Chris A: '81 GTV6 rescued from junkyard, "GT" car/'86 Porsche 944 Turbo track/street car/'73 BMW 2002tii fun street car/'74 Jensen Healey Lemons Rally car!
cda951 is offline  
post #9 of 14 (permalink) Old 10-09-2019, 09:09 AM Thread Starter
Registered User
 
Scott in MN's Avatar
 
Join Date: Jan 2005
Location: St. Paul, MN
Posts: 362
Garage
Thanks for the ideas. I wouldn't think it was vapor lock as the symptoms can occur with a cold engine. Won't start at all or starts and then dies backing out of garage. I had my injectors tuned up by the OK Injectors back in '13. Fuel filter is ~20K miles old but I could still replace it. Symptoms began last year after installing a new water pump/timing belt. Car had sat for 4 yrs prior to that while I built a new house.

How about the Ignition Control Module itself? I found some great posts dealing with it. I picked up a used Bosch 227 100 123 last night that I'll try when it arrives.

____________________________________________
[I]Why don't you knock it off with them negative waves? Why don't you dig how beautiful it is out here? Why don't you say something righteous and hopeful for a change?[/I]
Scott in MN is offline  
post #10 of 14 (permalink) Old 10-09-2019, 01:23 PM
Registered User
 
Join Date: Feb 2010
Location: Newport Beach, CA and Melbourne, Aus.
Posts: 1,277
Quote:
Originally Posted by cda951 View Post
Interesting. A clogged fuel filter usually causes issues at higher load when the engine demands a greater volume of fuel, but I would never talk anyone out of replacing it. Did you do any other fuel system work at the same time as the fuel filter replacement?
No, just that. I did cut the old one open though, out of interest. yuk!

Alister
1973 105 GTV (Alfa #6 of 19 owned)
Aggie57 is offline  
post #11 of 14 (permalink) Old 10-10-2019, 07:17 AM
Senior Member
Gold Subscriber
 
Join Date: Jun 2016
Location: Santa Barbara, CA
Posts: 238
Quote:
Originally Posted by Scott in MN View Post
Thanks for the ideas. I wouldn't think it was vapor lock as the symptoms can occur with a cold engine. Won't start at all or starts and then dies backing out of garage. I had my injectors tuned up by the OK Injectors back in '13. Fuel filter is ~20K miles old but I could still replace it. Symptoms began last year after installing a new water pump/timing belt. Car had sat for 4 yrs prior to that while I built a new house.

How about the Ignition Control Module itself? I found some great posts dealing with it. I picked up a used Bosch 227 100 123 last night that I'll try when it arrives.
Ah. In your first post you mentioned driving to the store and coming back out and the car won't start, etc, so I interpreted that as a warm starting issue.

I roughly described how to quickly check the ignition circuit in my first post (there are more comprehensive guides out there), might want to do that before replacing parts. But, yes, the ignition control module could be the problem. The reluctor in the distributor generates an AC voltage with a sine wave pattern, which goes to the ignition control module. The control module converts this signal to a digital square wave and sends it to the negative (terminal 1) of the coil. You can catch this switching signal with a test light.

But that connector at the distributor is also suspect. It gets a bit tricky with that as the ground is shielded, so standard wiring repairs will not work. I'd check the basic of the ignition circuit when it acts up and go from there . . . .

Chris A: '81 GTV6 rescued from junkyard, "GT" car/'86 Porsche 944 Turbo track/street car/'73 BMW 2002tii fun street car/'74 Jensen Healey Lemons Rally car!
cda951 is offline  
post #12 of 14 (permalink) Old 10-10-2019, 01:41 PM
Registered User
 
sportiva's Avatar
 
Join Date: Aug 2005
Location: Newcastle Australia
Posts: 502
Quote:
Originally Posted by Scott in MN View Post
How about the Ignition Control Module itself? I found some great posts dealing with it. I picked up a used Bosch 227 100 123 last night that I'll try when it arrives.
Does your car run the original 0 227100 117 alloy box ignition module? now if you want to replace this module with a Bosch
0 227 100 123 / 111 you will need an ev1 7pin male connector and will need to wire it as follows

Quote:
Originally Posted by sportiva View Post
The ignition module 0 227 100 111 will work as a direct replacement for the alloy cased 0227 100 017.
I have swapped mine over, My car has the two-wire VR inductive pick-up distributor. I used the module from my written off ALFA75 which has the three wire hall effect pick-up. It works perfectly with no over-heated coils, poor performance or misfires as long as you have the whole ignition system correctly wired.
My alloy box 0 227 100 017 amp had these colored wires they connect to the 0 227 100 111 as follows.

black/white.......................................connec t to #1
black............................................. ..................#2
green/black .................................................. ...#4

The 2 wires From the distributor are as follows
green and shield

green............................................. ..................#5
shield............................................ ...................#3
#6 and 7 are not used
You can use a BOSCH 0 227 100 111 a Tridon TIM 017, Fuelmiser CM413 or a BERU ZM 001 as a direct replacement for the 0 227 100 017 alloy box.
You will need a Bosch EV1 7 pin male connector. No other parts need to be replaced or modified.
The original post is here
http://www.alfabb.com/bb/forums/engi...ml#post8479308
Attached Images
 

Glen 3.0 GTV6 2.0 156 JTS
EX 1.2 Alfasud. 1.8 and 2.0 Alfetta's 2.5 Alfa75

Last edited by sportiva; 10-13-2019 at 03:25 PM. Reason: Added a link
sportiva is offline  
post #13 of 14 (permalink) Old 10-10-2019, 02:08 PM
Senior Member
Platinum Subscriber
 
alfaparticle's Avatar
 
Join Date: Oct 2004
Location: Columbia SC
Posts: 12,967
Rather than guess and replace try some systematic troubleshooting.
Mark the position distributor then remove it. With ignition ON, spin the distributor and listen for clicking of the injectors and sparking of the plugs. That should enable you to narrow down the cause of the problem before you start swapping things out.
sportiva likes this.

Ed Prytherch
79 Spider
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
alfaparticle is offline  
post #14 of 14 (permalink) Old 10-12-2019, 07:14 AM Thread Starter
Registered User
 
Scott in MN's Avatar
 
Join Date: Jan 2005
Location: St. Paul, MN
Posts: 362
Garage
[QUOTE=sportiva;8479604]Does your car run the original 0 227100 117 alloy box ignition module?

Yes, I still have that component.

____________________________________________
[I]Why don't you knock it off with them negative waves? Why don't you dig how beautiful it is out here? Why don't you say something righteous and hopeful for a change?[/I]
Scott in MN is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome