I started having problems after I got a bad cat back muffler system from FCP & it cracked open & the o 2 sensior finally flooded the Cat w carbon
[I m also dealing w a horrible LENOVO laptop..] I replaced Plugs plugwires coil wire CPS everything in the fuel & ignition system.
Now Im not getting any power to the RSS by the battery,,4 days ago I was getting power to the fuel pump harness & today NO,,The white relay underdash clicks & Ive switched out 2 & nothing ,,fuel filter has 2000 miles on it & fue;l pump is new lthough I suspect that may be another FCP defect..
Icleaned all the grounds I couldfind & sanded them clean any ideas would be appreciated,,

I’m certainly no ECU expert but you might consider taking it out and looking it over burn marks etc. Also check the condition of its wiring. Put a voltmeter on the wiring near where it attaches to the ECU and see what you get.

I don’t own a 7 or a 9 series Volvo but I do know that the 700/900 FAQ here in the BB is a great resource. Check for your issue in there!
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Will I buy another Volvo??? We'll see....

Here you go...

https://www.brickboard.com/FAQ/700-900/EngineFIComputer.htm
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Will I buy another Volvo??? We'll see....

Hi,

Check if your battery has full power. I've read sometime ago Regina can't start with weak battery. After so many starting attempts during these repairs your battery might have gone weak.

Nothing should have gone wrong with any wiring harness in the car as they're not moving anywhere, just vibrating in place. No internal break should occur unless they've been handled roughly during parts exchange. However there remains the issue of corrosion at the connectors. Check them.

Also check that you have enough fuel in tank and timing belt still intact.

Amarin.

yea it does,,I ran a jumper wire from 11 fuse to the relay,& red wire & pump started right up..

There might be enough juice to run the fuel pump but not enough to start the car. Put a voltmeter or multimeter on your battery and test it. You need at least 12 volts to start a car.
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Will I buy another Volvo??? We'll see....

BRAND NEW BATTERY

Doesn’t mean you didn’t drain the battery from a lot of cranking. Brand new battery doesn’t help if the battery cables are shot or alternator wiring is bad.
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Will I buy another Volvo??? We'll see....

Its got loads of power,,that s not the problem,I suspect its the ecu.something in that circuit??

Hi Blindboy,

I found this on turbo bricks (regarding Regina ECU - see the forum's posting #15 for inner photos)

https://forums.turbobricks.com/showthread.php?t=343330

Maybe you could let someone work on the ECU. Looks more DIY-friendly (from the photos) than Bosch ECU if I may say so.

Otherwise need to find good used one at eBay or the pull yard. I saw one at US eBay for $36. Need to match part number though.


Regards,
Amarin

what Ivw been reading now is that its most likely the ecu which is the source of my problems.
noid light shows injectors are working,

I beleive Ive narrowed it down to the ecu & the fuel circuit. I used noid lights & so the injectors are firing.. just that there is no power to the pump

Hi,
I would like to suggest this.

Why don’t you pull the relay out of the socket and remove the cover and then put it back.

Wrap the whole thing with a rubber band to hold both relays contacts closed for sure.

If the car then starts you will know it something to do with them not being told to close or they cannot get closed.
With the relay in the socket and manually closed, you want the car running cut the rubber bands and see which side of the relay drops out.
You can wiggle wires and all kinds of stuff with this setup doing things manually.
When you jump wiring that all you do is jump the problem without a result to contemplate.

Science and scientific methods say, to do one thing at a time, in some sort of sequence, to locate the cause for a change.

You are right on the cusps of locating the issue every time but jumping is just that!
The issue is just around a corner of a block that makes you go in a circle back to the beginning of the block.
So, you need to recognize that there are other corners to other blocks and change on a direction or method.
It’s all that I can suggest. The relay is a middle man with two jobs, pump and injectors with a couple other small things attached. The AMM and O2 sensor in the 240’s.

Phil

I wrapped the relay w rubber bands & now I hear the pump start for 2 seconds BUT it still doesnt start.

Hi,

Well, I have to say that it doesn’t make any sense.
On my 240s I can manually close the relay and with the key on in the position two and the pumps runs until I turn the key back off. You got to make sure you see the both sets of contacts make up.
Now I’m was under the impression that the ECU pluses on the pumps through the relay also.
So maybe something is not allowing power to the relay.
Bad ignition switch or fuses a terminal something somewhere.

I know the 900s are a little bit more updated and supposedly an improvement over the 700 series at the time.
Do you know if these newer cars utilize a different roll over valve that shuts off the pump?
If you have one of those it could need a reset.
Several American cars have them in later years than my 240s.
On those cars I have seen them near the electronics under the dashes or kick panels. The little 2000 Ford ranger pickups was my first experience seeing it.
I was tracing a 45 minute battery drain on the truck that wasn’t a whole lot but on real short to store trips the battery was suffering. It always turned itself off on it own.
A Mystery to me why Ford was doing that too and where? I told the person to keep a maintenance charger on it and that fixed it and saved him batteries.
The newer Volvo have all kinds of trick stuff that drains a battery, if the car is used like the one above, but Volvo can program them off in a customer service center, of course!

I sure hate to blame a ECU but the FAQS have a list for a reason.
All above my head and I cannot suggest anything else as I have no knowledge of the 900 series for the most part.
Will it fire up on starting fluid when it’s put into the intake manifold?
That checks out many things at once.

Phil

I ran a jumper from #11 to the red wire on relay.Pumps started up..so I think wire is broken some where..But car didnt started ?Maybe the injectors arent opening?

how durable are the relays?The radio relay by battery is new yet when the ey is turned I dont hear a click?

As I recall it was the cheap muffler support that rusted through in about 45 months so that cat/header joint hung down split& let extra oxygen in ,,that loaded the cat w extra fuel

This is a long shot as I’ve never owned a 940, but I think you may be barking up the wrong tree. Sounds like an electrical issue to me. I haven’t read all your posts so these suggestions might have already been made. Is your ECU original? If so it is almost 30 years and may have failed. 240’s had some bad ECU’s. Think you said you replaced the battery. What about the battery cables? The alternator wires? Have you done electrical testing on any of these?
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Will I buy another Volvo??? We'll see....

There is no pressure on the fuel line,

You said there is no electricity at the harness. If there is no electricity there will be no fuel pressure.
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Will I buy another Volvo??? We'll see....

cant figure iut what is causing lack of power?

Does anything happen when you try to start it? Clicking, cranks but no start, or is there nothing at all?

If nothing I would test the ECU. Again, if it’s original it is 30 years old and could be cooked.

You said you cleaned the grounds. Did you clean battery grounds and test the battery cables? Are the battery cables original? If so, they are overdue for replacement.

Also test the alternator wiring. Does your alternator have a red wire in the back? That wire is a known troublemaker in 240’s.
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Will I buy another Volvo??? We'll see....

I used my VOLT METER& THERE IS NO POWER AT THE FUEL PUMP FUSE,11.I SUSPECT IT MAY BE A LOOSE WIRE UNDER THE FUSE TRAY..iM CHARGING THE BATTERY OVER NIGHT & WILL CHECK AGAIN THE MORNING TO SEE IF i CAN TIGHTEN IT,



LENOVO LAPTOPS ARR CRAP

There is no pressure on the fuel line,