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'91 240 Wagon Won't Start Intermittently Topic is solved

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wholenewmom
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Year and Model: 1991 240 wagon
Location: Michigan
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'91 240 Wagon Won't Start Intermittently

Post by wholenewmom »

Our 1991 240 wagon wouldn't start one day but you can hear the fuel pump running and the car is turning over. Had it towed to the mechanic and of course when they went to work on it, it started fine. Drove a few times but then it wouldn't start again in a parking lot. Went back a few days later to check on the car/possibly get it towed, and the car started again. Drove it home and now it's dead in the driveway again.

Someone suggested that we try filling the tank and if it starts fine that it would help us diagnose, but I don't think that's going to help b/c it's started up again in those 2 situations that had nothing to do w/ more fuel being in the engine.

Would appreciate any thoughts as to what we can try to get it running again. Thanks so much in advance.

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volvolugnut
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Post by volvolugnut »

Intermittent starts are hard to diagnose.
I would start by connecting a fuel pressure gauge that you can leave on the car. When it does not start, see if you have fuel pressure. If it starts, note the fuel pressure when running.
Try some starter fluid in the air intake if you have a no start and see if it starts then. This will confirm a fuel delivery problem if it then starts.
Try to remove the corrugated air tube from the mass air flow meter to the throttle body. Then inspect carefully for any tears. These get bad over time and if leaking the air/fuel ratio is wrong.
Inspect for any vacuum tube leaks or crumbling tubes.
The Air flow meter may also have failed/failing.
volvolugnut
The Fleet:
Volvo: 2001 V70 T5, 1986 244DL, 1983 245DL, 1975 245DL, 1959 PV544, multiple Volvo parts cars.
Mercedes: 2001 E320, 1973 280, 1974 280C, 1989 300E, 1988 300TE, 1979 300TD, parts cars.
2009 Smart Passion
Ford: 1977 F350, 1964 F150 (2), 1938 Tudor Sedan
Farmall tractors: 1956 400 Diesel, 1946 A
And others.

122sPhil
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Post by 122sPhil »

when I change a main pump I like to connect a small bulb straight to the fuel pump so I know at a glance , in real time if it has power or perhaps relay trouble.

in a car that old I;d change the prepump and the fuel pump relay for reliability

if prepump fails it can run if the tank is full and will die at around 1/2 tank.
unhook the battery pull the fuseholder away so you can see it better.. remove all the fuses and give the whole thing a good cleaning.

below the intake manifold there is a plastic box called the flametrap, look at the hoses nearby and you can acually remove the flame trap they can crack too.
in that line you should see a little plastic screen clean or replace it, near ther is a S shaped tube, you can buy both cheaply.

if hoses start leaking then it can imbalnce the air fuel mix and mess up the idle,

if the screen plugs you can build crankcase presure that can maybe maybe blow the dipstick up and spiurt oil on a good day or blow out oil seals like your rear main oilseal on a bad day.

the feed for the in tank pump is a pink wire and it has a ground, black wire twith a screw to body

the other two are the fuel guage, leave that alone.

if you unhook the connector in the trunk you can feed the pink and ground the black then you should hear the prepump run. if you connect the pink to a test bulb and ground it , upon key on and during cranking and if it starts it shoudl be hot, the tank pump is being fed 12 V then.
normally when car is running remove filer cap , listen you should hear the prepump running inside the tank.

when cranking the tach or maybe the speedo . should pulse even if it doesnt; start, this pulse of the needle is verification that you have a pulse from the engine TDC sensor

if you have never changed the TDC sensoe I would just for reliability,

on models that are prior to the TDC sensor ( about 88) they will have a distributor hall sensor, the distributor is at the back of the engine then.
the hall sensors can and do fail and can cause intermittent stalling or no starts.

the car has a ignition computer the ignition comouter is different depending if its hall sensor or TDC sensor. by 91 it is a TDC or crankshaft sensor.

your 91 might have a fuel rail connector for a fuel pressure guage you can look.

the fuel pressure is unlikely the issue, there is a fuel pressure regulator on the fuel rail it has a rubber hose to the manifold, if that hose gets gas in it , this eans the FP regulator is bad.

Id varify fuel flow first. usually if it will not start it is ne of the fuel pumps or a relay a bad fuse connection. or it has lost its ignition pulse.

I once had rusty terninals ont he distributor coil.

if you put a small bulb across the coil trerminals ( spade connectors) then crank it you shouldl see flashing. the flasing indicates the primary coil is recieving a pulse.

if the coil has a piulse then you likely do have a spark , although possible you have a bad lead or bad distributor cap. just try clippong a small bulb across the col then crank it , if you do see a flash then as a pulse, that narrows down the cause of ignition related issues.

if you spray quick start in ( betwen air mass meter and intake ) and it starts, this verifies you have a working ignition system.









if you want you can [ull the hose off the main pump under the driver seat, put it in a gerry can and run the prepump, you should have an ample supply of fuel.

you can disconnet the fuel line to the fuel rail, I htink it is two 14mm wrenches, it will be tight initially. open that line and pu tthe end in a fuel can then you can check flow from the main pump

do not overfill yru fuel can and take obvious precautios, domt play wiht fuel indoors, have an extinguesher at your feet, keep sparks away , be careful.

if you like you can check fuel pressure at the rail, I dotn think there is a connector unleass its after about 1990 ? some may have a shraeder valve. ( tire valve) if there is no fitting for a guage you may need an adaptor to hook up a fuel pressure guage.

Be careful becaue that main pump can move a lot of fuel really fast and you can easily overfill your container.



.

122sPhil
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Post by 122sPhil »

I just worked on a 89 740 same thing really, same angine , same in tank pump.

the in tank pump died, the screen sock had fallen off , also the filter by the main pup was totally plugged up.

in 240s they hid relays all over in random places I think it's up under the passenger feet in that area, buit the thing moves around to different weird and hidden spaces between the years.

let the car sitr 5 mins, get in tna dturn the key, you houd hear it click on for about 1 second, if you hear the click it helps find the right relay.

the other thing that can totally kill the car i is the "radio suppresor relay" inm not sure if the 240 has it, in my 740's it is stuck to the water bottle..

this ( black ) relay has nothing at all to do with the radio, it is something to do with killing the engine in a crash. if you pull that relay out of a 740 it will not start. my 240 does not have one, in your 91, im not sure.

i think your prepump and main pump have separate fuses, check the labels on your fuesbox, make sure those two are conducting. a bad fuse can kill your car suddenly in traffic creating a danger. don't be happy with just "rolling it" thats fine for troubleshooting but if it has trouble , like green residue , murphys law says will come back and shut down your engine at the worst time possible. This can cause a serious crash.

122sPhil
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Post by 122sPhil »

I have seen it where the air mas meter had a problem with the connector terinals, Id remove it and clean that connector, they also can fail.
I thin if you start it with the AMM unhooked it will run, Ive seen it where unplugign one got it home , I guess in some sort of limp home mode with it unplugged. You might try with it unplugged.

i know in older 240s there ay be a main engine fuse it was somewhere around the inner fender on my 89 240. look for little white clip on box thing with a couple of big red wires, if you find a fuse in this area, verify the fuse hasn't gotten corroded.

the airbox has a preheating device, it is supposed to draw warm air from near the exhaust manifold during warmup. Ive heard of that sticking and defaulting to it being open and basically cooking the AMM

I replaced my air mas meter about a year ago. the bosche one was dear, around $1000 as I recall, so I put in a chinese one , it needed a little adjusting, thye have a screw to adjust Air fule and it may be capped off to prevent monkeying with the AF mix. might be best to have a mechaic adjust it if needed.

you cna remove the plugs and "read them" see if they are wet, or if they are fouled or if any look different from their friends.

if you do connect a fuel pressure guage you can verify if the pressure holds, if not it can mean an injector is leaking or it can also mean there is a bad check valve near the pump. leaking injectors are a bit rare and its not my first suspicion since its not starting.
if it happens you may see it barf white smoke upon startup intil it clears the cylinder of the extra fuel.

you cna check spark at the lugs with a helper or tape the button down on the timing light. to watch if it flashes, from the driver seat during cranking.

try foirst with quick start, if it fires up on quick start you have ignition.

if you have no ignition Id verify if the distributor has a pulse by connecting a small 12 V test lamp across the distributor coil wires. if that bulb doesnt; flash then I'd look for ignition pulse issues. if it does start on quick start look for reasons for no fuel flow, pump not running maybe if pumps both run check for fuel flow or see if the filter is plugged.

the fuel filter can be a battle to remove without breakign stuff, the aluminum case of it corrodes and those connections can be stufbborn.

on my most recent attempt I found I had damaged the small plastic line between the filer and the pump, this is not high pressure. I damaged that line because I was struggling with the filter connections.
I replaced it with some small fuel hose. it was some sort of vinyl line. if you can soource that small line its probably good to have a new OEM one. it only about 2 inches. a new one may include the little elbow fittings at the pump and at the fuel filter.

if you order a new in tank pump make sure to get a new screen too.

the whole mechanism that holds the float is plastic, by this date it may be quite dregraded. its basically just not intended for such a lifespan and a whole new one may be an option.

last time I orderd a fule pump for a 240 I got onethat was a bit too long. it hit the bottom of thetank I guess,, I bent hte whole thing so it sits on an angle and got away with it, but you could do better by making sure the new pump is the right length.

it may be commom for the prepump to dry out and squeak and get stuck if itis siltting out of the gas due to low fuel for some extended time. probably best to park it near full. if gas gets old take some out siphon it put it in another car so it can be refreshed. fuel conditioner and good gas without ethanol ( or alcohol) may help . If I store a car I try to add some high octane gas.

what I noted was that stuff like the fed pipes got a bit rusty the rust scale probably wrecked the pump because it had no screen. where is the screen? probably down in the bottom of the tank? I did not get too concerned. but would be best to clean the tank out, I just did not feel like having my head in the fuel fumes while squatting in the trunk for too long looking for the old screen. wearing a chemical resperator might help some.

I just did my 88 740 prepump yesterday. one thing I'd note is that the factory put the hose clamps on from underneath. hard to get them loose like that !

I didnt feel like jacking up the car and it looked like I had ugly spider webs and wet dirt and and stuff under there , instead I cut the hose clamps then put new ones they were then easily situated so I can tighten them up from above. sparks are a hazard. i cut them before any disassebly, with a dremil. sparks like that can can esily ignite fuel.
I did the prepump in my 240 sedan a year ago it seemed a bit easier to get in and out than a 740 sedan was.







you might choose to siphon the tank beforehand if you open it.

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volvolugnut
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Post by volvolugnut »

I think our original poster has moved on after one post.
Not a problem. Our information will still be useful for other 240 and 740 Volvos.
volvolugnut
The Fleet:
Volvo: 2001 V70 T5, 1986 244DL, 1983 245DL, 1975 245DL, 1959 PV544, multiple Volvo parts cars.
Mercedes: 2001 E320, 1973 280, 1974 280C, 1989 300E, 1988 300TE, 1979 300TD, parts cars.
2009 Smart Passion
Ford: 1977 F350, 1964 F150 (2), 1938 Tudor Sedan
Farmall tractors: 1956 400 Diesel, 1946 A
And others.

122sPhil
Posts: 43
Joined: 21 September 2025
Year and Model: 1966 122
Location: Vancouver BC
Has thanked: 1 time
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Post by 122sPhil »

hey I hope its ok if I veer off topic a little , I just noticed that in your tagline you put your fleet in there.
does your 1938 Tudor Sedan have a radio?

Volvolugnut I have a radio that is quite unique, it sports a V8 logo, it is round, fits into a dash, there are some cables ( approx 2 feet long ) that lead down to a radio which is built into a box and would have been located somewhere out of sight below the dash. it may be 6 volt if thats what was common back then. the radio itself looks nice it has not been restored or aligned or mucked with that Im am aware of. any radio that old does need some restoration to work as intended.

I recently stopped and discussed it with a guy with a similar car but he had his converted to chev and was an obvious hot rod, not at all a original car , so putting an AM radio in it wouldn't make as much sense. it shoudl go into a original car or truck of the era, He seemed to have converted this round hole in his dash into an ashtray. although it was a custom hot rod and not at all original it was very nice

when I looked at his grill it did sport the same V8 logo.

I collect AM radios and restore a few on occasion, I dont specialize in car radios. I have some underdash ones and such but this thing is very unique and specific and rare so , perhaps worth some money.

early car radios needed about 80 volts to make enough voltage to run vacuum tubes. they used a vibrator which made a sort of pulsed DC that DC could then be transformed to a higher voltage. it may comtian such a "vibrator?

what is the intent of your car? sounds interesting.




I think since it has the V8 logo ( the 8 is between the V) this means it is a ford,and the ford had a V8 engine stock. it is also a philco and philco and ford were the same company I think.. im not sure of the exact year but judging by the tubes its is close to that era.

of course this is an early AM reciever, it will not ever get FM, FM came much later on.

it must be a rather rare option, in 1938 radios were not common or expected in cars yet so it was a unique and maybe expensive option.

when WW2 started, radio manufacturers were drawn into producing military equipment so there was a gap before many domestic radios were produced again. this one was likely one of the last before this switchover of indiustry.

after the war radio tech was changed by improvements made during the war years. I am mainly interested in radios from about 1930 up to this era. they were examples of industrial art, art deco and such so there were a lot of fancy and attractive case designs. the style of the car is reflective of this era of design as well, I find it very beautiful.



Probably the person who would want it would be someone doing an authentic restoration on a ford with a V* from this era and he may have a round hole for it in the dash.

Hot rodders probably don't want AM radios.its cool but it shouls probably find itself in an authentic restoration.

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volvolugnut
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Post by volvolugnut »

Phil, Regarding my 1938 Ford:
It is still all original in very used condition. It has original small Ford V8 engine with valves in the block and a flat head. I hope to restore it at some time to all original condition, but time is getting away from me.
It does have a blank plate in the dash for a radio, but does not look to ever have had a radio. I think you are correct, radios were available but not common before WWII.
Yes I think these radios are collectable and would be different every year. I do not plan to ever install in my car because it would not be very useful as AM only.
volvolugnut
The Fleet:
Volvo: 2001 V70 T5, 1986 244DL, 1983 245DL, 1975 245DL, 1959 PV544, multiple Volvo parts cars.
Mercedes: 2001 E320, 1973 280, 1974 280C, 1989 300E, 1988 300TE, 1979 300TD, parts cars.
2009 Smart Passion
Ford: 1977 F350, 1964 F150 (2), 1938 Tudor Sedan
Farmall tractors: 1956 400 Diesel, 1946 A
And others.

wholenewmom
Posts: 3
Joined: 20 August 2025
Year and Model: 1991 240 wagon
Location: Michigan
Has thanked: 2 times

Post by wholenewmom »

volvolugnut wrote: 01 Oct 2025, 15:15 I think our original poster has moved on after one post.
Not a problem. Our information will still be useful for other 240 and 740 Volvos.
volvolugnut
Hi there. I haven't moved on. I am passing the super helpful info on to my husband and son who will be working on this but they have both been exceedingly busy. Another hangup we had is that I had a hard time figuring out what part to buy b/c there are a few and the owners of sites weren't responding to me at all so I got stuck there. I really appreciate all of the help so much and will be back after we try to address this. Thanks again!

wholenewmom
Posts: 3
Joined: 20 August 2025
Year and Model: 1991 240 wagon
Location: Michigan
Has thanked: 2 times

Post by wholenewmom »

volvolugnut wrote: 01 Oct 2025, 15:15 I think our original poster has moved on after one post.
Not a problem. Our information will still be useful for other 240 and 740 Volvos.
volvolugnut
Side note - someone mentioned this to me. Does this sound plausible or just ridiculously simple and likely not going to work?

"I had similar issues with my 940 and found the terminal on the negative battery node was loose. I was unable to tighten the bolt so I used a zip tie. "

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