Don B. Posted March 21, 2007 Share Posted March 21, 2007 My mother has an 1987 LeSabre and the car has a starting problem.The engine cranks but doesn't always start. When it resfuses to fireI've check for spark and there was none. The Cam sensor was replaced, cranksensor is undamaged, coil pack a year old. The connectors on the above sensors have been cleaned with contact cleaner.If I wait a few minutes it sometimes starts. This year engine is a little different than our Reatta's. It has 3 wires to the crank sensor not 4. Unless the crank sensor can be intermittantly bad I don't know where to look.The wires to the coil pack and harness are undamaged.It is hard to find a problem when it comes and goes.My mother has had to walk home from the store, she is 70+ old.I live 35 miles from her and this car is making me feel helpless.Ideas PLEASE!!Don't say a new car, she doesn't want one. The kids that liveon the block have no respect for others property, the adults aren't much better. Link to comment Share on other sites More sharing options...
harry yarnell Posted March 21, 2007 Share Posted March 21, 2007 Crank sensor would be right there at the top of my suspect list. Next would be the ignition module. That's about all there is (other than 12 volts) to the ignition system. Link to comment Share on other sites More sharing options...
Roadster90 Posted March 21, 2007 Share Posted March 21, 2007 With Harry on this...You have it pinned to ignition trouble. Your post is a little unclear though....Not sure from from your post if the car will run after it starts....if it does not only start, but actually runs at times (fails intermittently), go with or try the ICM (Ignition control module under the coil pack)....not a guarntee but a decent bet <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" /> otherwise the C/S sensor may be the culprit. Link to comment Share on other sites More sharing options...
Don B. Posted March 22, 2007 Author Share Posted March 22, 2007 The car runs fine it just does't always starts on every attempt. Link to comment Share on other sites More sharing options...
Roadster90 Posted March 22, 2007 Share Posted March 22, 2007 Info still a little vauge...more particulars would be helpful or are needed please...such as a symptoms log <img src="http://forums.aaca.org/images/graemlins/confused.gif" alt="" />If a Reatta or late 80's early 90's era 3800:If it runs fine after started...then cuts off and won't restart until after the engine and electrics have cooled (from a short while to even overnight), then it very possibly could be the ICM...may be worth a change out <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" />. Link to comment Share on other sites More sharing options...
Shelby Posted March 22, 2007 Share Posted March 22, 2007 Fuel pump Link to comment Share on other sites More sharing options...
padgett Posted March 22, 2007 Share Posted March 22, 2007 Why I posted the $100 list of Reatta test gear. In this case I would hook up a spark indicator, fuel pressure tester, and injector noid. My feeling from the symptoms is similar to Shelby's - fuel pump not reliably starting but could also be the fuel pump relay (only used in starting). In that case applying 12v to the prime lead for a few seconds should result in an immediate start. Link to comment Share on other sites More sharing options...
Roadster90 Posted March 22, 2007 Share Posted March 22, 2007 Padgett,You must have misread...the 1st post in the 1st paragraph he has stated when the engine would crank but not run, he checked and there was no spark....... Link to comment Share on other sites More sharing options...
Don B. Posted March 23, 2007 Author Share Posted March 23, 2007 I?ll make this short and sweet for those having comprehension trouble.The car acts like the cranks sensor is bad, but it doesn?t act that wayall the time.If anyone knows if a crank sensor can be intermittently bad then that is my answer. Link to comment Share on other sites More sharing options...
Don B. Posted March 23, 2007 Author Share Posted March 23, 2007 padgettIt is an ingition problem (no spark) but it comes and goes, so thatmakes it hard to find what is going defective. Link to comment Share on other sites More sharing options...
2seater Posted March 24, 2007 Share Posted March 24, 2007 I believe the '87 system is slightly different, but I know I have heard of situations where the crank sensor can be temperature sensitive. I have heard of people pouring water over it to cool it to see if it makes a difference. It is generally true the sensor either works or it doesn't, but my guess is the single ring sensor possibly fitted to the '87 may act somewhat differently? If the requirements are the same for the '87, only the crank sensor and ICM work to create the initial spark to start the engine, and of course the electrical feed to them. I think part of the problem with lack of help is the slightly different system used for the the '87 system. Very similar and yet different. Link to comment Share on other sites More sharing options...
padgett Posted March 24, 2007 Share Posted March 24, 2007 87 (LN3) is a considerably different engine and uses a single band crank balancer, different crank sensor, and different ignition module (connector is keyed differently). "Sometimes" still sounds like it might be an erratic fuel pump and is easier to check (with the prime wire and a good ear) or just pouring a 1/2 oz of gasoline into the plenium than ignition."No spark" is the balancer - sensor - ignition module - coil pack - plug wires - plugs system: it could be bad wiring between any of these.There is no substitute for plain old troubleshooting. Link to comment Share on other sites More sharing options...
sahein Posted March 30, 2007 Share Posted March 30, 2007 You might want to check the ignition switch. Link to comment Share on other sites More sharing options...
Don B. Posted April 1, 2007 Author Share Posted April 1, 2007 The Igntion switch? Please explain.The engine cranks every time the key is turned.There is no PASSKEY/VATS on this car. And of course car has be starting fine this pass week. Link to comment Share on other sites More sharing options...
sahein Posted September 19, 2007 Share Posted September 19, 2007 Sorry That I didn't see this post earlier.The ignition switch has more than 1 set of contacts. One set cranks the engine and the other set enables the ignition. Link to comment Share on other sites More sharing options...
Don B. Posted May 28, 2008 Author Share Posted May 28, 2008 Update on the '87 Lesabre.After removing the coil pack, for the 20th time, to check the connections I saw mark in the "gell" of the ignition module. I've noticed it before but thought it was just discoloration. Now it is much darker, it is a burn.I replaced the module at a cost of $110 {connector is different than Reatta}. I has been starting and running fine for over 3 months now.Thank you all for the suggestions, they helped me confirm my trouble shooting. Such an intermittant trouble is a pain to find. Link to comment Share on other sites More sharing options...
Barney Eaton Posted May 29, 2008 Share Posted May 29, 2008 Don... glad you posted a reply after fixing the '87Sometimes we make assumptions that are not true. In your first post, you said the coil pack was a year old.The assumption I made was that the coils and module under it were new.In addition, sometimes even new parts fail and we all believe because they are new, they can't be bad. Precistance pays off. Link to comment Share on other sites More sharing options...
Don B. Posted May 30, 2008 Author Share Posted May 30, 2008 Yea, the ignition module was original.I did not even think of mentioning it. Link to comment Share on other sites More sharing options...
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