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my fine running 1990 740 regina won't start. no symptoms. just refuses to fire. i decided to replace all the usual suspects, fuel pump relay, crank sensor, and radio suppression relay. no joy. the plugs are dry so it is a fuel problem. i am quite sure i hear the fuel pump run when i switch the ignition. my ears are not the best. the FAQS are leading me to question the ECU. apparently the L2.4 ECUs are failure prone, good for about 15 yrs before fuel pump circuit craps out. how do i tell which ECU i have. i have the number but am not really sure what it tells me. one of the confusing details is the car's regina system. the ECU is bendix not bosch.
to further complicate matters, the volvo fix for cold injector problems back in 1990 has left me with a permanent 321 code on the fuel side of the obd. so no help from obd.
any ideas?
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I don't see the results of Lucid's suggestion to jumper the RSR; have you done that? Simply insert a wire jumper between the two heavier wires in the RSR connector. It sounds like you swapped out the RSR prior to posting, but are you sure it was the RSR and not the identical fan relay right beside it on the strut tower. If you insert a jumper and the fan comes on you are at the wrong connector.
Ground problems are not necessarily limited to cars in Northern climes, its a good idea to check and clean them on any car- especially one that is 20 years old.
You can fashion your own diagnostic pressure gauge with the fuel rail connections and a trip to your local hardware store:
Edit: ie "fuel rail connections" harvested from a parts car, pick and pull, ...
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thanks for the photo detailing the fuel pressure rig. big help! i did follow lucids jumper instructions. car started right up. i remain confused in that one of the first things i did was to replace the rsr with a new one. still no start. what do you suppose that indicates. jumper she runs, known good rsr she doesn't run.
thanks again for the picture!
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May be dirty contacts on the female connector.
I have had problems with thr RSR and am thinking of making the jumper permanent meaning splcing those 2 cables and eliminating the relay.
I know some other volvo's do not use it.
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Rstarkie,
I gave you a thumbs up because I liked the picture.
Thanks!
Goatman
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The Radio (noise) supression Relay can be a problem on both the Bosch and Regina FI systems if it fails to pass voltage to the injectors. Even with good fuel pressure the plugs will stay dry.
It should be tucked up out of sight along the right side inner fender, about even with the ABS modulator, and you may have to cut or unfasten a plastic tie strap to get it free.
To bypass the relay, unplug the connector and insert a small "U" of thick wire into the sockets for the two thicker wires (Red and Green-Red). Use fairly thick wire so it will stay in place, like a piece of coat hanger scraped clean for good electrical contact.
"to further complicate matters, the volvo fix for cold injector problems back in 1990 has left me with a permanent 321 code on the fuel side of the obd. so no help from obd."
That permanent 321 doesn't affect the use of the OBD system at all, except it might reduce the number of stored Fuel codes from 3 to 2. Not sure about that.
"one of the confusing details is the car's regina system"
Not sure what that means, since the LH and Regina are virtually identical in operation except for the way they sense engine load to control fuel mixture (with the Regina being more reliable if anything).
The picture below shows my RSR (with green tape), where I hung it on the ABS unit while troubleshooting a problem.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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If you have a Regina car then yes, you have the Bendix ECU, not an LHxx. The Bendix ECU's have a reputation for being bullet proof - probably the LAST component to suspect in your troubleshooting.
I'll assume you have verified, without a doubt, that you have spark and that your cam (and consequently the ignition) are in time.
You've replaced some of the typically suspicious components. You think you're hearing the pump, but is it really delivering fuel to the engine at the correct PSI? When was the filter last replaced? If your pump has never been replaced, I would really take a close look at that. Regina owners seem to report pump failure at around 150-175,000 miles. Another thing that can happen is that the pump's hose connection inside the tank fails so that you hear the pump running but it doesn't deliver the correct pressure. A pressure gauge connected at the injector rail could be very telling as to what's going on.
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chris, thanks for the response.
there is spark. the plugs are dry. unfortunately i am not set up to check fuel pressure and this 740 doesn't make it easy, no shrader. the filter is an unknown factor, but the previous owner maintained the car well so i would speculate it is ok. my previous experience with filters is that they first cause problems under load, not in starting. i agree that the fuel pump is a suspect. my '94 mod. 940 needed a new pump at about 150,000, but there were symptoms leading up to the final failure. i did thump the bottom of the tank of the 740 with no results. i think the cam timing is fine. cranking sounds normal. if it had skipped a tooth or two it probably would at least try to start. this is a dead no fire.
i'm going to get set up to check fuel pressure. with these FI cars it is an essential diagnostic tool
thanks again!
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After an extended crank, no start, pull a spark plug. Is plug wet with gas? If it is then you likely have fuel pressure. If its completely dry and doesnt smell of gas then I would listen to Lucid and jumper the RSR. That or your Fuel Pump relay or CPS are the likely candidates. Or you could just take the return fuel line off the back of the FPR and let it dump into a jar as your helper cranks the engine...
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the plugs are dry. there is spark. i replaced the fpr, rsr, and cps. there is spark. my next move is to test the pressure regulator.
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Replacing the RSR won't help if it has a bad ground, like mine did. That's why I suggested a bypass jumper above. That would quickly eliminate it from the list of known suspects.
The ground connector that stopped me is shown below, in back of the right headlight and hard to see behind all the wiring (moved out of the way in the pic).
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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Plugs are dry then you have a fuel/injector issue. If you have a "noid" light you should test the injectors to make sure they are getting pulsed, its easy.
Without the car running I dont know if you can do the "pop the fuel return line off and let it run into glass jar and see how fast it fills" test, as you will only have the initial "prime pressure"....unless you have one of those vacuum testers?
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would the regulator test work with the car cranking? will check the ground as suggested by lucid, but it looks good. this is a southern car so doesn't suffer from the corroded grounds, etc. like northern cars. where do i get a "noid" light?
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Not sure if it will work w/car cranking but not running. That being said its unlikely the FPR has failed to the extent to no allow starting. Noid light:
http://www.ehow.com/how_4453009_test-voltage-fuel-injectors-noid.html http://www.amazon.com/OTC-7188-Bosch-Noid-Light/dp/B000P72CMW
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does the "noid" light work with the regina system? ipd sells one but suggests that it is only for bosch.
thanks, chris
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I think IPD is wrong there. Both Bosch and Regina use the same connectors on the injectors. Other makes (Ford, GM, etc.) are probably different. It would have been more accurate for them to say "Bosch Type.
You may be able to get one locally at one of the larger chains like NAPA.
The term 'noid is short for solenoid, the electrical term for what an injector actually is.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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Hi,
I hate to disturb this neat thread, but I just can't find a good reason not to.
Just place your warm rosy fingertips onto the cold filthy fuel injectors as another keys the starter. If they are operating electrically it will be quite obvious.
Goatman
--
I am looking for an honest man. - Diogenes of Sinope
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i will try feeling for the click of the injector, although a gadget like the "noid" is too hard to resist. gotta have it!
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