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Hi:
I have complained on at least 2 different threads about how my 89 240 does a "No Start" when we have wet conditions - drizzle. rain, fog mist etc... .
So, taking the advice of several, a few days ago I ordered a new dist. cap, rotor, wires and coil.
In the time since I ordered (and have yet to receive parts), we have had 3 days of continuous drizzle , light rain, fog and mist - and the car has started and run fine - no problems at all.
I am completely baffled????
(Sorry Re-posted from "all" forum)
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This assumes that your car cranks okay, but doesn't catch (i.e., start) -- it wasn't very clear because you only said it doesn't "start" and I'm not sure if it even cranks. If this is not right, forget the following:
Okay, you changed the plug wires, distributor cap, etc., and also considered the fuse panel under the windshield corner (viz., rain leaks).
But it doesn't sound like a rain leak problem because you have the same problem in just foggy/misty conditions. So it sounds like merely the moisture in the air -- a problem I had and solved.
You have to carefully check the high voltage (spark plug) wires' paths along the engine.
In my case, a had a wire (the one from the coil to the center of the distributor cap) laying in a little plastic bracket/holder. It looked good, but in fact it was too close to a metal bracket, and (when the air was moist) there was a conduction path from the wire to that grounding point. I just had to cover that point of proximity with an old piece of rubber hose (to thicken the insulation) and the problem was solved.
On a dark night (or in an unlit garage), lift the hood and have someone try to start the car while you look at the engine compartment. You should look for a spark occurring over the path of those secondary wires.
Good luck.
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Thanks for your response.
I did fail to mention that car does crank - but no start.
Very interesting what you mention because I was thinking about that last night.
The nice little plastic clips that hold the wires off of the valve cover or other places could easily become a path to ground. Whatever plastic they are made of would most likely not be of correct composition to be a strong dielectric.
Then add some water with contaminants - you have a really nice ground path.
So, I thought about getting some nice silicone thin wall hose and placing the spark and coil wires in it where it is near metal.
However, my 240 started just fine the past 3 days with this messy rainy, foggy, misty stuff we have now. So, again I'm still baffled.
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So you have changed/inspected 25 amp fuse and holder, crank position sensor, and fuel pump relay already? Spun the fuses to break up any oxidation. O and most importantly fixed the leaky cabin.
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Yes mostly.... 25 amp fuse/holder - yes, new Bougi CPS, New relay. No , have recently spun fuses. Windshield still leaks as does the sunroof.
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Its easy enough to remove the fuel pump relay and inspect. The original ones are dated coded as well. The orientation in the car is such that if your leaking above it water will get in it. Worse case you put it back in top side up.
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Oh. My recollection was we were pretty certain it was raining inside your car and you were going to junk it, rather than bothering to solve the leak.
1. You need new wires, plugs, cap'n'rotor. Been drilled into us since we're old enough to drive, just like fuel filters and air filters. Cars need tune-ups. And that is what a tune-up is nowadays. You'll be all tuned up.
2. This thread is about the frustration of diagnosing intermittent behavior. Guessing not at all the history, sounds to me like it is time to throw away a lot of assumptions and start over with the facts. A new title would be apropos.
--
Art Benstein near Baltimore
Happy New Year!
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Yes, I recall the leaking windshield issue relating to the instruments not functioning, but not relating to the no start condition.
My comments about junking the car were not serious, though I see some folks were offended.
[QUOTE] A new title would be apropos.[/QUOTE]
**Sorry, won't let me change title. Thread responded to.**
The facts still remain the same regarding the wet no start issue and the conditions in which they occur as stated here and in previous posts with the exception of this instance of starting in wet conditions. All previous no starts in wet conditions have been as I stated - no start when wet - rainy, foggy , mist, drizzle etc... .
And yes, it is frustrating to try to diagnose a no start condition based on the assumptions I have taken from here.
My thoughts were as I stated that the "maintenance items" to be replaced would have probably been the culprit. I am less sure now and thus have to look elsewhere and I see that as becoming much more complex.
As an electrical engineer, (no offense to all) I find car wiring systems for whatever reason to be extremely counter intuitive in design and schematics do not follow norm as I am acquainted with and as such are difficult to use.
Static or dynamic mechanical issues are much less time consuming to diagnose.
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Wow, I'm surprised. You're an EE? That's great!
This car is absolutely the right car for a double-E. It employs mechanical design from the 60's and 70's -- accessible to anyone. It advances into the 90's to the puzzlement of most, with electronics. For you (and I) who grew up on Ohm's law these systems present little challenge. These are systems you can still take apart and largely reverse engineer, yet the manufacturer provides us with the documentation to explain the design and function and help us relate it to the physical implementation at the replaceable module level.
Go back 20 years and you don't really need your EE. Step forward 20 and you need the source code. 240's are ideal for you and me.
You can't, and don't want to change the title of this thread. My titling suggestion is mostly for those who come to search later, not just the bored, cooped-up by winter Brickboard regulars like me who reply to anything. I am suggesting you start a thread based on what your car's symptoms are without making any assumptions on the cause. Simply include links to your "previous posts" if you don't want to repeat the facts of the symptoms and onset. But for this thread, approaching an intermittent symptom with a diagnostic plan is a good and worthy topic. Most just throw parts at it.
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Art Benstein near Baltimore
The glass is completely full. Half with water and half with air.
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Hi Art, Happy New Year
This may be a solution to the riddle but I find the terms 'completely full' and 'half full' to be equally confusing. Like 'dead', empty and full are states that either exist or don't exist, and they don't lend themselves well to being scaled. In my mind they are kin to the mathematical terms zero and infinity.
Another solution I like is to change the terms empty and full to emptied and filled. The addition of a vector component allows one to differentiate a glass that is half filled from a glass that is half emptied even though they may contain the same volume of water. Being distinct, the two glasses may then be given different values.
A corollary to this is that if one encounters two glasses of water containing the same volume in a static state, the glasses cannot be differentiated. They are the same and must have the same value.
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Ok Art ..: ).
Yes, well I'm helping a good friend with a nightmare AKA an Audi A4 circa 2005.
We are reverse engineering some things relating to feedback loops in control systems for the ECU and Mod codes that don't address specific performance issues. Glad it's not my car.
But the 240 has the Fuel Injection "computer" and ignition "computer" with a lot of hard coded comparator stuff as well as some code I haven't had the time to poke around in. Looks like maybe some basic functions in PROM and cute ASICs.
Forgot the nice little Bosch thin/thick film Hybrids.
Still , the darn functional dwgs and schematics just really chap me. Guess I'm an standards elitist. : )
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"Still , the darn functional dwgs and schematics just really chap me. Guess I'm an standards elitist."
Edit: "...standards elitist" that was a ha-ha, wasn't it. Sorry, missed it.
I don't know why you say this. Maybe I would know better if you would just give me an example of a schematic representation of physical electronics you would find "intuitive" or comforting. Just a link to any drawing would work. What is elite? Maybe I can help interpret.
Seriously, I'd like to get into some real discussions on this board about diagnostics, both in general, and specific to the 240. Part swap Sherlock Holmes elimination has its advantages with professionals and DIYers, but without follow up and root cause analysis, we learn nothing. Just a list of likely failures based on anecdotes, like, did you replace the xx relay. The xx relay is what fixed mine.
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Art Benstein near Baltimore
An artist, and architect, and an engineer were at the bar discussing the relative values and enjoyment of mistresses and wives.
The artist decided, 'I would much rather have my mistress! It is always exciting and a little bit naughty and different.'
The architect said, 'I much prefer my wife. I like the stability and certainty.'
The engineer said, 'I like to have both. That way, my wife can think I'm with my mistress, my mistress can think I'm with my wife, and I can get back to the plant to get some work done.'
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Well,my dry sense of humor .... yes.
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Ok Art. Let me find my drawings from the Haynes/Volvo in PDF format and I will PM one to you. To me they are just confusing as heck in as much as they are block/pseudo-schematic representations.
Also, I not much on throwing parts at a car. I'm too cheap and conservative to do that - I drive an 89 Volvo. As you say this really does nothing to diagnose and analyze - kind of a shotgun approach that I don't care for.
I have for some time wanted to take my DSO out to the 240 and measure the wave form of the CPS to determine the amplitude and period at various speeds including cranking. Same for the AMM and other little sensor/devices that have nothing more than static resistance or voltage values. Then print the results into a PDF file,
(all of this assumes correct function at the time of measurement)
with values measured for the CPS and converted to RMS voltage at a given speed into a table/RPM/crankspeed, a cheap volt meter with the ability to read AC at a few KHz. could give great feedback about what is going on with the CPS or other device - just an example....
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Hold on there, pardner. I know what the drawings in Haynes look like. I know the drawings in Volvos green books. Like most here, I've squinted at the reproductions in Bentley. Those you do NOT need to send me PM or link. I want to see just one example of a schematic you DO like. That will help with interpretation. Yes, there is a learning curve associated with every industry's peculiarities in creating service information meant for technicians. I can help you with questions on the symbols and conventions used in Volvo's wiring diagrams, which are "schematic" by definition, but not schematics in the sense electrical designers use the term.
Here's a link. Tell me if you think this is what you mean by standards and easily read, and its function understood: k-jet controller
The measurements you are thinking about have in most cases been posted on this board, so the baseline is already available to you. And yes, you could wire in your cheap AC voltmeter across your CPS and leave it in the passenger's footwell for when it craps out again. I can tell you the pitfalls of that approach as well, but in a thread dedicated to solving your no-start, not this one.
--
Art Benstein near Baltimore
There are 10 different kinds of people.
Those who understand binary, and those who don't.
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