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1993 945T 180k miles
Questions:
1. Can anyone confirm the RSR (Radio suppression relay) has the following information on the relay part?
- Top of part:
Volvo
899931 1323592-1
12V/40A
- Left side, close to the connectors, white painted lettering
270392
2. This relay is sealed at the bottom with some soft material. Can I cut it open to attempt the resoldering fix, then reseal it back with some silicon sealant?
I am experiencing frequent stall / hot start problem. I followed the FAQ "Hot Start Problem Diagnosis and Repair" section, replaced the fuel injection relay, (p/n 3523608), but the problem persists. Chased down the location of the RSR (?) on the driverside fender, mounted to a piece of metal bracket, below a bunch of wiring harness. In this 15 dF temperature I broke the clip on the plastic case to remove it from its mounting location. I compared this to the tiny pictures in the FAQ 'EngineFuelinjection.htm#Radio_Suppression_Relay' page. They look very close to the part in my hand except that what apprears to be pin out diagram in the left hand side picture is not on my RSR (again, ?).
Much TIA,
Lih-Yen Hsieh
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I had an intermittant no start problem with my '93 940. Eventually I replaced the crank position sensor and found the problem. The insulation jacket on the sensor cable had deteriorated right at the point where the cable went into the sensor. The jacket had split allowing the insulation on the three wires inside the jacket to weather and crumble. When the cable was moved a very little amount, these wires could short out rendering the sensor inoperative. A little motion in the other direction and the sensor worked.
Replacing this sensor is easy, 10 minute job. Well maybe longer if you are wearing mittens. there is a small bolt holding the sensor to the bellhousing and the connector on the cable. you have to work by feel.
Given the rotten weather you are having, you may not want to do the job. You could try feeling the sensor cable where I found mine split to at least know if that could be your problem. Good luck!
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1993 945T, 180k miles
I replaced the FI relay, cleaned intake track, reslodered the RSR, but the car now refusees to start at all, just cranks and cranks. Fuel pump(s?) appears to work as I could hear hums. Engine would seem to catch once in a while but never fired up.
The car started to have idle problem a couple of weeks back - every few seconds there was a drop in RPM. Two days ago it stalled on highway. Code 1-1-1. Restarted after lengthy cool down. Replaced FI relay, cleaned intake track. Cold starting was not smooth but eventually caught on, and once warmed up it held up for quite a while. Drove the car back with two stalls en route the 25 miles drive, with one interleaving instance of power loss. The first stall didn't take long to restart but the second one required some cool down (did not take that long when it was 15 degrees outside.) Code 1-1-1. RSR solder joints looked not bad but I resoldered everyone anyway (would've replace it if I had a new part in hand, given the mileage.) Car started with some difficulty but came on anyway and then ran fine for a few miles, but with a drop in idle RPM every 1.5 seconds or so. Cut it off after that, then it would not start again.
Now it is what, about 5 degrees outside? In this kind of weather and without the use of a garage I am having it towed to Jaffarian tomorrow. But if anyone has any advise to share, including what to tell this Volvo dealership, please pass it on.
Much TIA,
Lih-Yen Hsieh
Freezing in Andover, MA
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Dear Lih-Yen,
Good a.m. and may this find you well. This might be an rpm (crank) sensor problem. If the sensor fails, it does not detect rotation of the flywheel or flexplate, so fuel pumps don't send fuel. I gather you hear fuel pumps running, which might remove the crank sensor from consideration. Are you 100% sure the fuel pumps are operating? Do they run for a second or two, or do they run continually?
The drops in rpm - and the stalls - suggest the crank sensor could be failing.
Hope this helps.
Yours faithfully,
spook
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Hello,
Hi, Spook,
Thanks. The RPM sensor is the next logical thing to look at, I suppose. The 700/900 FAQ also suggests this.
The pumps definitely operate for 1.5 seconds after turning the key to the ON position, they then stop. But when I cranked it I am not sure I definitely heard them continue to run due to the cranking noise. However, immediately after I switched the key off when cranking, there seemed continue to be a humming sound for a split second which was then followed by some clicking sounds. I suppose it takes a discernable amount of time for the relays to switch off after the key is turned off. This is all possible to hear in the dead quietness of the ambient. Does this somehow exonerate the RPM sensor to a certain degree? Also, elsewhere I saw the name 'reference sensor'; is it the same thing?
I also noticed that if I turned the key off and on quickly then I did not hear either relays turn on clicking or pumps running. But if I switch the key off crisply, waited a second or two, then turn it back on again, I almost always heard the relay clicking and pump humming.
Thanks again,
Lih-Yen
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Dear Lih-Yen,
Good a.m. To be able to do this analysis, we need to agree on terms.
The RPM sensor works once the starter has turned the flywheel/flexplate.The RPM sensor detects the rotation, and allows power to flow to the fuel pumps, so that the engine can start. This arrangement promotes safety. If, as a result of collision damage, the engine stops turning, then the fuel pumps cease to send fuel to the engine. This reduces fire risk.
My ignition switch (1993 940) is marked 0, "I", "II", and "III" (the double quotes will separate Roman Numeral I from the capital letter I). In position 0, the steering wheel is locked. In position "I", power flows to accessories, i.e., a radar detector. However, when the key is in position I, the systems indicator lights at the bottom of the instrument cluster are still dark.
When I move the key to position "II", the systems indicator lights are lit.
Only when I move the key to position "III", does the starter motor begin to turn. If I hold the key there, the engine will fire-up.
When I moved the key from "I" to "II", I heard the fuel pumps come on for about a second. Then, they stopped. If I had continued to turn the key to "III", the starter would have activated, and the engine would have fired-up.
Based on what you told me, you heard the fuel pumps run for a second, as you moved your key from "I" to "II". Once you got to position "III" the sound of cranking hid any fuel pump noises.
My guess is that there are no fuel pump noises, because the crank sensor is not sending the signal to the fuel pumps.
One way to check this - if you can find a helper - is for them to move the key from position "II" to position "III", after you have gone to the back of the car and listen for the fuel pumps. In a sedan, you probably should put your head inside the trunk, towards the front. In a wagon, put your head close to the load space floor, towards the front of the loadspace.
If you hear the fuel pumps running while the engine is cranking, that exonerates the crank/RPM sensor. If the pumps aren't running, then the crank/RPM sensor is a suspect (and you probably should read it the Miranda warning).
Hope this helps.
Yours faithfully,
spook
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Spook,
Everything you said was what I meant to, except what the fuel pumps did when I was cranking the engine. I'll have to find out with a helper and a stethoscope (well, a piece of tubing stuck down the filler neck.)
I am guessing another possibility, which is a very weak battery complicating the no start symptom. This morning my other car, an 89 Merkur XR4ti, wouldn't start until AAA truck came to jump it. It gave me a clue that maybe the warm start problem after resoldering the RSR was indeed a typical warm start problem caused by RPM sensor, and later in the night, the cold start problem was because the battery was just plainly too low, and so the sparks were way too weak.
I am going to try to jump start the car after I get home this evening, and verify the fuel pump operation and let you know. The appointment with Jaffarian is tomorrow, but I think I am going to honor it - there is no warm relief in sight for the next few days.
Thanks again,
Lih-Yen
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Dear Lih-Yen,
Good p.m. My mechanic is is North Reading, MA, which can't be all that far from Jaffarian's.
My mechanic will figure out what's wrong in a few micro-seconds.
As he's very busy, he fixes only that which must be fixed. If you're curious to know more, message me directly and let me have your e-mail, and I'll provide details.
Yours faithfully,
spook
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That part number on the top agrees with the number on a RSR which I took out of a 740 in a salvage yard. I believe that the fan relay is identical and you can try swapping them. If you need confirmation on that relay part number, I can go out and look at the 940 in my driveway.
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Jim,
Thanks for the confirmaiton. I wouldn't think there is a need to run out to check it on your car, but I sincerely appreciate the offer.
I looked up the schematics in the Haynes 940 manual for a little more info. Here is what I found:
1. RSR (injector relay) for B230FT (LH2.4) and B280E/F (LH2.2) are the same.
2. RSR for B6304FS is largely the same, except that a) pins for the load and the feed are reversed, and b) there is a built-in diode from trigger return (pin 85) to power feed (pin 87), which I assume is for clamping back EMF arc when the relay opens (just guessing.)
3. CFR (Cooling fan relay) for B280 and B230 are the same as RSR for B230FT (and B280 E/F), but the schematic is not specific about B230FT. However, please see my note below.
4. CFR for B204FT and B66304FS has 5 pins, and the fan switch circuit is much more complicated.
Note:
There is a difference in mechanical configuration between the RSR and the fan relay above:
- For the RSR (1., 2.), the moving contact point is tied to the load, while
- For the fan relay (3.) the moving contact point is tied to the 12V feed.
I am sure there is the difference was based on some non-trivial consideration but I am not conversant in that area. Therefore I am not sure that, these relays are truely identical in that sense, and, swapping them is really a good idea.
As I mentioned in my original post, the fan relay in my car does not look like the RSR at all. As a matter of fact, it has white lettering on its front that says something like 'Cooling Fan Relay', and it is about 2"+ wide, 1" thick, and about 2"- tall, and is mounted behind the driver side headlight. So I didn't even bother. I think my fan relay is very definitely not swappable with the RSR. Considering the note above, though, I am wondering if I should suggest our FAQ maintainer(s) to consider revising some sections re. swapping relays for testing purpose. The seemingly haphazard approach Volvo chose to implement the circuits (particularly non-standard use of relays, and very inconsistent wire coloring schemes, which almost differs from model to model) alone is confusing enough. Maybe those tech tips apply to 700 line or earlier model years, but at least the 945T I have is quite different. Just a thought.
Lih-Yen Hsieh
Andover, MA (north of Boston)
1993 945T, 180k
1989 Merkur XR4ti, 182k
1987 Merkur XR4ti, 88k
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You are correct about the two relays being different. I don't recall where I read that information. It may have refered to the earlier models which used the belt driven fan and which had an auxiliary electric fan. The cooling fan relay for the '93 940 has two coils. I found the relay to be controlled by the engine temperature, the AC hi pressure and AC low pressure sensors. This would provide two speed operation.
However, the RSR is a very simple relay and you can check it by applying 12v to pins 1 and 2 and checking for continuity across pins 3 and 4. It is a single pole NO relay. I checked the junkyard one I picked up, actually I got two of them.
I was interested to learn from Don Foster that these can be opened up. I wonder if they go bad very often. They are much simpler than the FP relays.
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Jim,
Thanks again.
I was interested to learn from Don Foster that these can be opened up. I wonder if they go bad very often. They are much simpler than the FP relays.
The RSR can be opened up as Don Foster said, and can be resoldered all the same as the FI relay. The plastic case, as a matter of fact, is dimenssionally identical to the FI relay, including the attahing clip, but seems to be more flexible than the FI relay. The bottom is sealed with some type of sealant, due to it being under the hood.
Lih-Yen Hsieh
Andover, MA (north of Boston)
1993 945T, 180k
1989 Merkur XR4ti, 182k
1987 Merkur XR4ti, 88k
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Can't confirm the part numbers.
Yes, the relays underhood are sealed with a soft material. When I resoldered my (intermittent) RSR, I resealed it with RTV.
Resolder EVERY relay in your car. What's to lose except a little time?
--
Don Foster (near Cape Cod, MA)
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Thanks, Don. I just resoldered it and resealed it with RTV silicon. Will see if this solves the problem.
New question:
What are other relays do you suggest that are worth the effort of resoldering? (Oh, yes, I had resoldered the FI relay, and even though the solder joints still look like they are holding up, the contact points have pitted so I replaced it with a new one.)
According to the FAQ the RSR is identical to the cooling fan relay. However, in my car the cooling fan relay does not look like it's the same as the RSR - the fan relay has two or three connectors to it.
I looked up FCP Groton web site but but couldn't find the RSR. The cooling fan relay they list has a number P2031-62650 with a price of $55.35. Can't talk to them right now, so we shall see.
Lih-Yen Hsieh
Andover, MA (north of Boston)
1993 945T, 180k
1989 Merkur XR4ti, 182k
1987 Merkur XR4ti, 88k
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Can't hurt to do 'em all.
The RSR, FI, and OD relays are the key relays to resolder.
After my wife got stuck with our '91 740 -- bad FI relay -- and again 2 weeks later -- bad RSR -- I got frustrated and resoldered everything in sight.
I only wish I could resolder the headliner.
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Don Foster (near Cape Cod, MA)
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Ive done four 700 series headliners, and one heater core. Although the jobs aren't related, I'd rather replace another heater core before I did another headliner in a 700 series.
--
john
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That's NOT what I want to hear.
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Don Foster (near Cape Cod, MA)
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Don, and John,
The last thing I'd worry about right now is the headliner soldering challenge. :) Well, heater core might be another weak spot but if the car would start at least it'd get me to somewhere warm.
Hey, would you folks please chime in on the other spawn thread, re: "No start at all (was: Radio suppression relay) ]]"?
A side topic, Don, I heard you guys down at the cape are going to get stormed. Have you mounted the snow blade yet? At least that'll you give you some added front traction. :)
Much TIA,
Lih-Yen
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