Hello All!

Christmas eve was not the best time for my 245 to not start after going to the hardware store!

It is now in my garage after AAA tow ... and I've found the following to be true:

1. It tries to start (turns over and runs shortly on cranking rather than just cranking) when spraying starting fluid into the intake, it doesn't stay running.

2. as mentioned there is no pump sound after jumping fuse 4 and 6 (left contacts)

3. FI Relay under passenger side footwell carpet clicks a few seconds after ignition is turned off from cranking

4. plugs are dry after several attempts cranking (I've tried to start it periodically after longer periods of not trying so it may be possible that the fuel lines are not filled but I don't think so)

5. Cam is turning during cranking by looking inside the oil filler cap

6. 25 Amp fuse (in newer water resistant fuse holder) is good. Connections from it to battery seem good

7. FI relay has been swapped with known good relay to no avail (still clicks after ignition off)

8. I have spark using my spark tester inserted into an unplugged spark plug wire and grounded to the engine block

9. I have removed the air filter so as to make sure a clogged air filter was not the problem.

I think I'm down to confirming that the main fuel pump has bit the dust but I wanted to confirm that I didn't miss anything before trying to swap that out and finding that the ultimate fix was easier.

any help, as always, is greatly appreciated!

Jack
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Bad Blue - '86 245 with 303,000 mi. (now for parts), Good Green 1990 245 with 178,000 mi., Blacky - '91 740 wagon with 180,000 mi., Mean Green - '94 850 with 222,000

The last in tank pump I got from FCP was wired backwards. If I hadn't noticed and installed it as it was, it would've been sucking fuel back from the front of the car instead of pushing fuel out towards the main pump. I bet it would've run, but it certainly wouldn't've been long before it fried the main pump from that little game of tug of war. I can't remember the wire colors off the top of my head, but make sure they match all the way through from the car to the harness to the actual connections on the pump.

Afton
'68 220; '88 & '92 245s; '98 XC

hello
with a backward wired intank pump the car will start but run for a few seconds.
at least for me thats how it worked.
good luck
Mike

Hey Mike, it might depend on how full the tank is, how cool the fuel is, and how much vacuum the main pump can develop (how good it sucks for its age). Mine got me 100 miles.
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Art Benstein near Baltimore

He often broke into song because he couldn't find the key.

I remember your post on that a couple years ago. You noticed this was the aftermarket sender assembly (not the pump) and it identified the problem I had. I took photos, and have since purchased 3 more of those sender assemblies, all of which were wired backward, just like you found. Pics are in here, and thank you once again, Afton. In The Tank
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Art Benstein near Baltimore

I am in shape. Round's a shape...

Right! It was the sender assembly, wasn't it? Thanks for correcting that for me Art. I think I'll go ahead and blame that one on getting old.....

Best,
Afton
'68 220; '88 & '92 245s; '98 XC

I'd be in the same boat if cameras still required film.

Well after continued troubleshooting I found that there was no voltage at the electrical leads to the main fuel pump itself. Working backwards from there I found the connector underneath the back seat bottom and found 12 V at that connector.

I tested the wires (both ground and hot) between under the seat and the connections to the fuel pump itself and they were good.

so I was confused ... I cleaned the contacts at the fuel pump (on the wires not the pump) put it back together and it started up!

unfortunately after buttoning things all back up again it stopped working so I suspected that connection under the seat. I wiggled it... reattached it and it started.

now it seems to be running so I think my problem was electrical connection related but I'm expecting it to fail again.

hopefully I'll remember this experience when it won't start in a year!

Jack
--
Bad Blue - '86 245 with 303,000 mi. (now for parts), Good Green 1990 245 with 178,000 mi., Blacky - '91 740 wagon with 180,000 mi., Mean Green - '94 850 with 222,000

Did you remove, clean up and reattach the ground connection under the seat?

Randy

Yes - I made sure it was tight this time!
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Bad Blue - '86 245 with 303,000 mi. (now for parts), Good Green 1990 245 with 178,000 mi., Blacky - '91 740 wagon with 180,000 mi., Mean Green - '94 850 with 222,000

Ok - I figured I'd come back and post what the problem turned out to be.

Whenever I messed with the wires near the pump I would jostle the pump enough and it would start, but I didn't realize that's what I was doing

After a few of these events I thought it may be the fuel pump intermittently working so I figured I'd try tapping the pump the next time it wouldn't start. Sure enough that did it - just a quick tap got it running again - so main fuel pump failed.... Replaced it with a good pump I had from my old 240 and went to start it up again and nothing - after several cranks it finally started - then I remembered that BB'ers said main pumps fail after the in tank pumps failed and caused the main pumps to overwork delivering fuel. So I listened for my in tank pump and heard nothing.

After more disassembly and stethoscoping the intank pump it was clear that I had found the culprit of the whole problem - an unnoticed failed in-tank pump. Ordered the part from FCP and now am hearing the hum of two fuel pumps.

If only I had heard the in-tank pump fail!

How would anyone notice their in-tank pump was no longer working without regularly checking it?
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Bad Blue - '86 245 with 303,000 mi. (now for parts), Good Green 1990 245 with 178,000 mi., Blacky - '91 740 wagon with 180,000 mi., Mean Green - '94 850 with 222,000

"How would anyone notice their in-tank pump was no longer working without regularly checking it?"

Exactly. It will not usually become a problem until you're 100 miles from home on a hot summer afternoon. Given the experiences I've had, I've added a check of the tank pump to the oil change routine. Here's how I do it:

On the LH2.4 cars (89-91 in my fleet) I remove fuse #4 and put +12 to the load side (right side) and listen. Doing it this way removes any ambiguity about which pump you are hearing. If I can't hear it, or I'm not changing the oil and it is noisy by the side of the road, I disconnect the oxygen sensor heater wire and look for a spark as the jumper is placed.

On my k-jet cars (79-83 in my fleet) the fuse to remove is #5, and there's no oxygen sensor wiring associated.


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Art Benstein near Baltimore

Never raise your hands to your kids. It leaves your groin unprotected.

Thanks Art and all other posters in this thread!

I will add these checks to my maintenance routines so I can find out how long my aftermarket pump runs ... and my new (old) main pump.

Jack
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Bad Blue - '86 245 with 303,000 mi. (now for parts), Good Green 1990 245 with 178,000 mi., Blacky - '91 740 wagon with 180,000 mi., Mean Green - '94 850 with 222,000

"Replaced it [main] with a good pump I had from my old 240 and went to start it up again and nothing - after several cranks it finally started ..."

So it would start and run repeatedly without a good in-tank pump? The hard initial start was just the new (old) main priming the system?

I don't have much of an ear for the in-tank pump so I usually pull the access plate and listen through a steel rod. If it's a car I don't know and want to rely on - eg. going away to college w/ someone - I pull the in-tank pump to inspect wires, hose, fittings, sender, etc. And I often replace them ~$35 seems a good investment in this area.
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240s: 2 drivers & parts cars

"So it would start and run repeatedly without a good in-tank pump? The hard initial start was just the new (old) main priming the system?"

Yes - after some cranking the main pump would run the car seemingly fine although it would sometimes take a little more cranking to turn it over.

I drove it around the city here and there on this condition while waiting for my in-tank pump to arrive from FCP - probably not a good idea due to potentially wearing out my new (old) main pump faster. I'm definitely gonna have to watch for premature failure of my newly installed pumps. But I am back on the road now. We'll see how long it lasts!
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Bad Blue - '86 245 with 303,000 mi. (now for parts), Good Green 1990 245 with 178,000 mi., Blacky - '91 740 wagon with 180,000 mi., Mean Green - '94 850 with 222,000

Every now and again I open the gas pump door and listen for the hum. I also remember way back whenever my main pump failed it was noticeably louder before it failed-a somewhat high pitched weeeeeeeeeee.

Anyway, glad you got everything sorted out and posted back with your results.

Travis

No but that is clearly a must do in this situation.

It looks so clean and is held so tightly that I just made the assumption. But clearly looks could be deceiving in this unresolved (but functioning) problem.

I am experiencing some intermittent unstable idling.

Yes I will clean it up and check it before driving again - thanks!

Jack
--
Bad Blue - '86 245 with 303,000 mi. (now for parts), Good Green 1990 245 with 178,000 mi., Blacky - '91 740 wagon with 180,000 mi., Mean Green - '94 850 with 222,000