1990 740GL that has sat a whole lot...
Gas gauge showed it was quite low a while ago when it died on me after leaving it outdoors overnight after picking up a friend and driving their car home.
I started it up, it ran 10 seconds and died. Restarted it and it did it again. Then it cranked and sputtered but no start. I could hear the fuel pumps running, but it felt like fuel starvation. Started and it died again.

After I let it sit a few minutes, I restarted it and let it run a few minutes... it had no issues and then idled and revved in Park for 10 minutes. I drove it to a gas station and filled it up. Drove it home with no problems.

About a month later, tank still full, I started it yesterday. It did the same thing - seemed fine, then died and wouldn't restart.

While the list of possible issues is long, I think that there is a good chance there is water in the fuel. I bought a bottle of "Iso Heet" that's purely Methanol. It will mix the water into the fuel if there's only a little. But I'm not thrilled about the idea of putting it into the fuel tank and it potentially damaging something or being on the wrong track.

Do these symptoms sound like water in the fuel tank? If so, can I just drain a little and see it easily?

Cheers,
Will

Hi Will,

Like you said there's a long list of culprits for a car that's sat for a long time.

Check for OBD codes for starters. See if the ECU's report anything.

Bill

I'm about to reply to MachineMan below. Please check it out!

Hi,

I went through something very similar with my 1993 240 I picked up in 2017 from Reno Nevada.

It would start and run and die is some random amount of mileage or times, at first.
It seemed like fuel starvation as well.
But it got slowly worse to where the car was not dependable.

I traced it to a problem, I thought, to be a dead in-tank pump, thinking it was an intermittent issue before dying. I put in a new one as the old one was definitely dead.

I restarted the car and it seemed to work just fine and then it shut off. Just like with the turn of a key.
This made me rethink ignition so it could be either a CPS, going funky, or the electronic relay that fires the ignition coil per the ICU’s instructions.
On a 240 it’s located behind the battery that often gets neglected because of that reason alone.

So I had a new CPS and changed it. It looked original, so why not, as they do fail in mysterious ways from mine own others experiences on the BB.

I tired it up again and it ran about thirty seconds again and it just turned off.
So I started thinking about that hidden relay.
I got in there and saw something I totally forgot about from about five years ago.
I treat all relay sockets to a maintenance bath of anti corrosion salve. Once every ten years is for my coastal climate but I try to keep them indoors too.
If car is kept outside in the weather doing it more often is advisable.

When I got the car it a broken connector to that relay. Its spring lock was not there I think and one side was missing.
I didn’t have one of those in any stash on a wiring harness ei, then!
So I wire tied it together by slotting the aluminum base to get the wires ties to fit under it and still have contact with the cars body for cooling.
But since that time, I picked up one complete wiring harness with a spare engine from a JY 1990 model.

So I unpinned them both, wire by wire, noting colors and placement. I tossed the old connector.
Somewhere in its lifetime something petroleum, I surmise, got on the plastic.
It the housing was very brittle and a chunk was missing.
What it could have been is still a mystery. It’s the only one I have seen bad.


I started the car again but it hit that repetitive 30 seconds again! I said ok, I will abandon that relay and put on another spare replacement from my stash.
Fired it up again. It kept on running and running?
I said wow, that was it.
So far all has been just fine for the last year and a half!
I’m sure glad too.
The next thing for me would have been to change the ICU. I hate to point to any computer boards.

Patience and using my parts department came through for me again.
I marked the relay as questionable and kept it but I’m too lazy to put in back in to check it.
“If it ain’t broke don’t fix it” is getting to be this old man’s mantra.
Maybe, if I ever need to replace a battery 🤭. Nah! Don’t mess with success.

I will suggest you put a timing light or tachometer on the ignition wires to see if either quits while the engine still coasts down.
I think that’s what gave me some insight along the way.
It is tricky to say how well it works but while grasping around for straws, pay it some mind for finding a flower. 🤭
But the biggest thing I notice was the TIME factor to the shut downs.
Call it an instinct or an arm fitted with a wrist watch, a habit of wisdom gained.

A feeling that was like the ECU goes through a “warm up” sequence series of a program lines with attached protocols.
It checks itself for sensor inputs like rpm, O2, coolant temp or AMM.
If one or more does not send correct feed back or does it not compare, precisely, it will shuts down.
Maybe a safety thing … like saying “don’t drive me!”
The “limping” mode is another well known computer routine.

I have read that the CPS signals are closely watched to be in a certain wave shape and strength so as not to use some erroneous interference.

Good luck and let patience wear it down to find that gremlin.

Phil

Hi, Phil!

I swear I had put a reply up the other day...

Thank you for your reply! It inspired me to actually go and look at it and the run/die run/die pattern. Your kind of long-form reply really gives me something to think about and I went and took a look. It's the beginning of a long week at work that promises to be rough, so I'm going to keep it pretty short.

An LED probe in the injectors showed power and pulses both with the self-test OBD function and with the cranking all the way until it sputtered and died.

Cold-Start Injector, Injectors, RSR, and IAC all work on the self-test mode. The RSR itself looks good and the fan relay is a little ugly.

The TPS registers that I turned the throttle and the CPS registers that I cranked the engine.

The interesting thing... it runs on starting fluid although it doesn't run for quite as long as I would expect - I am stingy with the starting fluid.

One thing that I think is quite odd - the fuel pump under the car *sounds* different. Like a different pitch and not making the burbling noises it has in the past as air bubbles move through the line. I have to turn the key on and off several times to avoid a long crank. It was normal for a while for it to go weeee... weeee.... weeneeewamam ... weeedbebdebe.... weebdbzzbz... weebdbdbd... weeeeeee (but at a different pitch).


Now I'm wondering if there's a chance this is a progression of what's been going on this whole time with the fuel sender being a bit wonky.

I've been meaning I need to pull the fuel sender but it's been too darn cold and I am smart enough not to run my diesel construction heater with the gas tank open...


What do you all think?

Hi Will,

Please check for OBD codes at Port 2 & 6.
If you get any, clear them and see what codes remain.

That's where to start diagnosis. The ECU's may help you get to the fault.

Then you can try disconnecting the negative battery cable for ten seconds
and hook it up again, and see if that gets the car started. That clears
the memory of the ICU's and has worked here after sudden engine misbehavior.

Post back with your results.

Bill

Rats!

I pulled the battery cable off to make sure I didn't short anything while I was working on that alternator ground. I had to loosen all of the 3 bolts for the manifold to block brace. It was off for a good 5 or 10 minutes.

I hadn't bothered to read the codes before since it was so sudden.

Hi Will,

That happened here when the car quit, I was in a hurry and unhooked the battery before checking codes, join the club.

If it still wont start check the OBD codes and see what you get.
After you get all 1-1-1's, lets go from there.

Bill

I checked the codes and all I got was this lousy T-shirt that says 223 (idle air valve unhooked) - but that's because I did unhook it for testing.

Socket 6 had no codes. Reset both and reading 111, but what I'm getting now is a similar start and die in a few seconds. The change in tone of the fuel pump really has me thinking it's water in the gas. One more day to my weekend, and I'll pull off the fuel line under the car and pump some into a container to look at it.

Hi Will,

What engine in your car? B230FT ? LH2.2 or LH2.4 ?
Did you test your AMM? If not test it. See FAQ
Do you get a strong pulse of gas from the fuel rail valve after trying to start?

Give an email address and I'll send a troubleshoot manual for "no start".

I do like Phil's post about servicing connectors, however I would not dissemble
the harness bullet connectors at the firewall or you could wind up with a major
repair job. LEAVE THEM ALONE! Focus on the AMM, CPS, Ignition, RSR, connectors.
Use Penetrox-A on those connectors.

You could jump the RSR to test (see FAQ)
Better to retire your old Main fuel relay and RSR with new.
Don't trust junk yard pulls for those two critical relays, use only
for emergency spares.

The sockets can fail.
The main fuel relay socket is just female 0.250" spade lugs and they get loose
after multiple extractions and insertions.
Make a test gauge using a 1/4" male spade lug crimped on a hunk of stiff solid copper, and make sure the pins are not loose.
You can put some Penetrox-A in each female pin for better long term reliability.

The RSR is a bullet connector and the molded rubber that holds the female pins can disintegrate. If you aren't aware you can swap out the RSR and not make a solid connection if the pins are loose in the connector housing.

You could measure current flow for fuse 1 and 11 and get an idea of fuel circuitry health.
Here's what I get in the 1993 B230FT LH 2.4
Fuse 1 10.5 Amps Both pumps +
Fuse 11 3.5 Amps in-tank pump only

Good luck, Bill

Welllll I found the problem. It was really bothering me that the pump sounded different. I undid one of the fittings to see what comes out of the in-tank pump line. I wanted to check it for water in the fuel.
Found the problem... the external pump is completely dry and there is 0 output from the in-tank pump.


Good thing I filled the tank up all the way... -cries in gasoline fumes-

This is a b230f 1990 Regina/Rex - but I put an external pump on it after my friend had problems with the fuel system. Now that I've muddled my way through the external plumbing (which was a real adventure) and put a new pump in under the car, I need to convert the tank pump to the bosch version.

I also think the sending unit is misaligned or the pump is installed too low because the tank bung nut won't quite screw in all the way because the sender is sticking out ever so slightly.

Removing and installing 700/900 sending units can be tricky. If your sending unit isn't fully seated down on the tank flange then that's likely an installation problem. Yours should have the spring loaded barrel. You need to keep the barrel pulled up off the bottom until the face is flush on the rubber collar before tightening the plastic collar then release the barrel. It's described in the FAQ how to use a loop of fishing line to accomplish this. This was a trick that Spook used and told us about. I've done this project a number of times over the years, so here's the way I do it:

o You loop the fishing line around the bottom of the barrel clip and run both ends up through the return line nipple. Pull the barrel all the way back by hand then tie the lines around the nipple to hold it. You need maybe 4'-6' of line. A super strong thread or fine string can also be used.

o Now install the sending unit, going through various gyrations of angling it and turning it to get it into the anti-slosh bucket without knocking the filter sock off. It will take a few attempts. Look down with a flashlight first to see what you're up against.

o Keep the face of the sender pushed flat on the rubber collar while you install and snug up the threaded plastic collar with the other hand.

o Install and moderately tighten the metal ring clamp around the plastic collar so the collar can't expand and jump threads during final tightening. Now tighten the plastic collar as hard as you can by hand. If the plastic collar is allowed to expand and starts jumping threads then the threads will start to strip and it will need replacement. The 700s (leastwise up to my 1989) didn't come with a metal ring clamp, so if needed get a 4" *stainless steel* ring clamp at a hardware store. Originally, Volvo called for a new plastic ring to always be used until they figured the ring clamp trick.

o For a final tightening, with a non-sparking drift (foot long wood stick) held at a 45deg or so angle against the collar tabs, use a hammer to tap around the plastic collar to tighten it another 1/8-1/4 turn (depending on how hand tight you got it, just 1/8 min and no more than about a 1/4 turn) then do a final tightening of the ring clamp.

o Undo the fishing line to release the barrel and pull one end up through the nipple to remove it. Reconnect the hoses and you should be good to go.

o To ensure there are no leaks, dry the area around the flange thoroughly before installing the hatch. Over the coming days and especially after you next fill up, stick you nose around the rear wheels and smell for gas vapours accumulating up under the fenders. Once or twice check underneath to see if there are fuel stains on the side of the tank (will typically be the axle side). End the project by re-opening the hatch to verify that the top of the tank remains dry.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Hi,

Glad to hear it wasn’t a water in the fuel problem.

I have seen the seven series pump arrangement along with the instrument clusters being made in Japan.
The introduction of the 700 made me not like its GM or Chrysler Le Baron looks to begin with.
Despite the seating interiors looked to be more creature friendly and all.
I have learned that if they go to the trouble to hide the interior decor without showing how the cars become more of an expensive looking luxury to Volvo that was an upgrade but not for true blooded 200 series eyes.

I too have wondered why they turned their back on the 240 in-tank fuel arrangement.
At least they kept the topside access available.
Having to drop complete gas tanks on some cars is a major chore.

I’m not sure even if Bosch even makes those feed pumps as there are so many replacements from other brands like Delphi, AC Delco or VDO for many other cars.

I have noticed that the original in tank pumps on the 240s had a ring extrusion on the main body. Those have disappeared.
My tank senders used it in their holders to keep the pump up into the factory accordion hose.
This allowed the pump to float upwards but not down lower than that ring as not to pull on the connectors hose. No clamps were used as I remember.

So with new replacements I have always added a tight a #6 grade nylon wire tie to the body of the pump above the holder after assembly.
It will do the same thing as the extruded ring in function.

I was wondering the sending unit on 700s might that have the pump is held down lower on the overall stack up. It would explain the tight fit vertically.
This is if a connecting hose too long or was straight and stiff. Bingo?

Did you notice if they designed the sender in such a fashion?

Or like you said, improvise!

Phil

Hi,

Glad to hear it wasn’t a water in the fuel problem.

I have seen the seven series pump arrangement along with the instrument clusters being made in Japan.
The introduction of the 700 made me not like its GM or Chrysler Le Baron looks to begin with.
Despite the seating interiors looked to be more creature friendly and all.
I have learned that if they go to the trouble to hide the interior decor without showing how the cars become more of an expensive looking luxury to Volvo that was an upgrade but not for true blooded 200 series eyes.

I too have wondered why they turned their back on the 240 in-tank fuel arrangement.
At least they kept the topside access available.
Having to drop complete gas tanks on some cars is a major chore.

I’m not sure even if Bosch even makes those feed pumps as there are so many replacements from other brands like Delphi, AC Delco or VDO for many other cars.

I have noticed that the original in tank pumps on the 240s had a ring extrusion on the main body. Those have disappeared.
My tank senders used it in their holders to keep the pump up into the factory accordion hose.
This allowed the pump to float upwards but not down lower than that ring as not to pull on the connectors hose. No clamps were used as I remember.

So with new replacements I have always added a tight a #6 grade nylon wire tie to the body of the pump above the holder after assembly.
It will do the same thing as the extruded ring in function.

I was wondering the sending unit on 700s might that have the pump is held down lower on the overall stack up. It would explain the tight fit vertically.
This is if a connecting hose too long or was straight and stiff. Bingo?

Did you notice if they designed the sender in such a fashion?

Or like you said, improvise!

Phil

Regina? Thanks for mentioning that.

Glad you fixed it.