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She has been running great, only 156,000 mi. Car fairly new to me so I don't know much about it. Dash air vents were not working consistently so I've been taking the dash all apart and checking for vacuum leaks. So, I've been working under the dash and tracing vacuum lines under the hood. Have replaced the main line and the check valve. Had the battery disconnected while doing this. I disconnected the door switch so I wouldn't have to listen to the warning chime... Could this have any effect? Decided to start & do some testing and she starts, but dies. Can't keep running even with more throttle. Smells rich. Did I touch something? Or is this just coincidence that something decided to break now? BTW, the check engine light came on once the other day on a 160mi trip and could not find any reason. Never ran badly and the light cleared itself. I don't know where to start in the FAQs. Any hint would be greatly appreciated.
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Bob
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Check for OBD codes
how is the spark?
are the plugs fouled?
see the 700-900 FAQ for plenty of help.
Bill
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Hey Bill,
This is (or was) a fuel problem. Hooked the battery up yesterday & no codes. Reconnected the door switch, she started right up and ran perfectly. Doubt that had anything to do with it, but will check later when I put the dash back together. Went for a test drive and all is well. No codes. I had not figured the OBD out until now, but if I get a check engine light again, will check it. I now realize that the Bentley manual for the 240 series also covers this engine. That is a relief.
It appears that the solution of plugging the vacuum line to the servo for the recirc/outside air flapper servo fixes the AC problem.
This car is in near perfect condition and all I have done so far is the usual changing of all fluids, belts, brakes and shocks, plus checking plugs, etc. and replacing some vacuum lines. Is this going to be one of those impossible to diagnose intermittent problems? Any hints as to what would cause this loss of idle control and what looked like fuel starving would be appreciated.
Bob
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Bob
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Hi Bob,
Get the Volvo wiring manual for your car, all others are a poor second best.
Go here: https://www.matthewsvolvosite.com/forums/viewtopic.php?t=34333
see if you hit paydirt. You want the Volvo book TPXXXXXXX.
also go here for the volvo engine schematics and component locations:
http://www.autoelectric.ru/auto/volvo/740/1989/740-89.htm
There's two relays that can kill fuel.
The main fuel relay in the main fuseblock, and the RSR in the engine bay.
They are computer controlled and often get squirrely by failing intermittently.
Only replace with new relays for these two.
Bill
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Thanks Bill,
I really appreciate your time. I have so far struck out trying to find a Volvo manual, but will keep looking. I will print out the info you linked to. RSR? Is that the Radio Supression Relay? I see a relay clipped to the left shock tower behind the power steering reservoir that I suspect is what you are talking about. The former owner gave me two relays and one looks like that, but has the wrong connector. I already bought a CPS and have not installed it yet. I haven't even figured out how to get the distributor cap off yet.
From what I am reading, humidity and heat can cause problems. That would make sense because it acted up when hot. When parked inside in a cool garage it starts perfectly.
I will try to buy replacements. It is pretty frustrating that they had to make these things so complicated. I'm seeing why some people go to a lot of work and expense to find old manifolds and carbs, going back to the good old days of poor power and mileage in exchange for reliability. Funny, when I bought my '84 244 somebody asked me who I would find to work on the injection. I responded that with a manual and VOM they are pretty simple. I live over 60 miles from a dealer and don't think they have anybody working there who is old enough to be an expert. They have zero parts. I couldn't even buy lug nuts there for the 244!! This 745T is a bit daunting.
I bought the 745T this to be our occasional highway car. It is the first one we have owned in 20 years that gets washed and waxed. The 244 is a gravel road, local beater. An old Jeep is the snow plow and a 99 F250 carries loads and a camper. All except the 740 are way over 200,000 miles.
Bob in very rural Montana (There is only one other 740 in the county and I've only seen one other 240)
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Bob
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Mornin Bill,
I already bought the Haynes #1258. Always have preffered Haynes. I am one of those guys who will take a car to the shop only if it is the transmission. My first car was a 56 VW that I rebuilt myself at 16. Worked in gas stations and have never understood how anybody can't change their own oil. Just spent 3 days replacing glow plugs, one injector and such on my Ford diesel that has 230K on it and it runs like new. I have done those glow plugs 3 times. I forgot how much work it is.
I've been buying parts from IPD. They have access to real Volvo parts and their service is great. They offer a USB drive manual they say is Volvo for $75... Have you ever looked at that? I would need a new computer since I switched to Mac. Might just do that. They also have the relay for $20 and I have it in my cart. I'm sure the fuel relay the PO gave me is new and it is Volvo OEM.
Have not looked at the plugs because it runs so good. Bought new plugs & cap. The only thing I did on the engine so far is oil, check timing, adjust idle and install a K&N air filter.
All the records of dealer service were included. It looks to me like the PO was just up against too much with 4 kids to keep up with and gave up on his plans for this car. He had new rotors, headlights, spare wheels with new snow tires, on & on in spare parts, but it was just sitting in his garage. The rotors were rusty! I trust they did all the belts on schedule and I just did them all again. I installed the front rotors & OEM pads all around, changed brake fluid, new rear OEM shocks. The struts had been recently done by a shop, as well as tie rod ends and it has the IPD rear suspension upgrades. Mechanically, this car is perfect. Handles like a sports car, goes like a scalded cat and with white paint is a sleeper. Exactly what I had looking for for the last 5 years. I installed the Eurospec headlights and I will ignore the tiny dents. Might try to fix the speedometer and he gave me two spares, but a phone app works fine.
My email is bobanene@gmail. I don't see yours.
Bob
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Bob
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Hi Bob,
OK on Montana,
Volvo factory trained 740 techs are mostly retired.
You need a service library.
Check your local library network for auto repair data services.
Tell me if there's a good one for Volvo- some are crap.
None I've seen come remotely close to genuine Volvo.
I like the Haynes manuals. You want #1258. Search used books.
It gives nice details for installing stuff like the distributor.
The earlier Haynes book for the 740 #97040 (1550) is for 1982-1988
and a lot of the items are the same. Send me an email and I'll give you
another link that might find the Volvo wiring manual you want.
Big brother (Google & friends proxy sites) will rent the manual to you for $29.99/year instead of coughing up the free info. This is another reason why monopoly search engines suck.
YES! Change out ALL of your old vacuum lines, elbows etc.
Hopefully you have service records about the T-belt, water pump etc.
Yes the RSR is near the P/S reservoir and can disable the injectors.
It is controlled by the main fuel relay. Change out both of them since they
are old and tired, and your car will croak when they act up.
Search ebay for "Fuel Pump Relay 35236082"
The Swedish auto parts relay works OK for $20.
Ebay craps out today for the RSR:
Last summer, new was $20, Now... NO SOAP!
Check here for a Taiwan offering:
https://www.amazon.com/MTC-VP602-1323592-Relay-models/dp/B00BDVP1YU
DON'T MESS WITH USED RELAYS! UGH!
The OBD system doesn't reset itself.
Check again, each port for 1-1-1
Look at your ignition at night in the dark: Look for corona around the coil,
wires and distributor cap. Moisture aggravates any faults there.
Use only an OEM quality Distributor cap!
You never said what the plugs look like after the car acts up?
The plugs tell a story.
Cheers, Bill
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