i have a 1983 244gl with a blown up 503 ecu,found a 507 online put it in runs great but anything above 2800 rpm no power.im going to try a 510 because i cant find 503

i cant believe how well it runs for not running in 14 years spending half the time sitting in the woods and the engine 3 qt over with gasoline.

To add to Art's comment that the 510 ECU will substitute for the 503, I pulled a 510 from a 1984 240, and swapped it for the 503 in my early-production 1983 240.

No difference in engine operation...starting, running, fuel economy, etc...so I've left it there and have the 503 in the trunk as backup. 19 years now. But I did have to replace the failed original -2 AMM after 29 years and about 170k miles. Was lucky to find two, so one on the engine and one in the trunk.
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Son's XC70, daughter's XC60, my 83 244DL, 89 745 (Chev LT-1 V8), and XC60. Also '77 MGB with Chev V6, and four old motorcycles. Long gone: 1981 244, 1994 940,1998 S90 and 2010XC60 (totalled by hitting 500lb elk)

both fuel pumps new

Fuel pressure regulator and check valve. Must be correct for ECU to function correctly.

quick update,the 510 came in last night,plugged it in and the car runs awsome! so a 507 will not work in place of a 503

also pocking around under the hood i noticed my ignition coil got quite warm.so i took a ohm reading of the coil high tention lead and found to be 2.3k ohms.im going to try a 0 ohm coil wire to see if it helps

yes swapping my coil wire from a 2.3k ohm to a 0 ohm made my coil happy

thanks for all the great information,i hope you got my joke about LH and RH. well i found a 510 on evilbay for $30 shipped so when it comes in ill post my results

I have a 503 pink label from a running car. E-mail me fastforwardphoto(AT)yahoo(DOT)com -- Dave

Have you checked your fuel pressure ?

Hi,

I don’t see a 510 model for the 240 of that year or any year on my list. Maybe I have an incomplete list.

http://www.nuceng.ca/bill/volvo/database/ecu.htm

Are you sure that the power issue is only the ECU? It’s very possible that the AMM can gone bad as it’s one of the first models out. In fact the year makes its components at the very beginning of the LH systems. You can see, from above, the follow up revisions over the next several years.

I have read that Getting the pins out corrected between or to each unit is where the game is played on some later years. There have been gurus in the past in discussion of this but all of that is well over my head.
You might want to research the possibility of upgrading it somehow and post your endeavors.

I have a 1984 LH 1.0 and the AMM 002 has gone bad three times since the car was new. I’m the second owner and diagnosed the first one bad for that original owner around 100k
It’s how I got to know them at my workplace and got offered the car to me after the insurance company wanted to total it for a damages left rear door with 112k. Buy back was $700 to me, from the owners, over 20 years ago. (:-)
I have now replaced it again about 70,000 miles later with another rebuilt one. The car is standing close to 190k miles.

In the mean time, I stashed away another one Bosch found on a JY car. I use it to test with. But instead of having it smoke out it, I put on rebuilder ones.
I don’t remember the brands of the other ones but I surmise that the rebuilds on these do not do very well.

I have had good luck with the Injection Labs company products on my 1986 that a another hard to find 007. I believe they are out of Nevada somewhere and the parts store that carry them put on a lifetime warranty.
I won’t go wrong until they cannot get them anymore.
Hopefully they will have to give me my money back. If that’s is how it will works? Depending on what LIFETIME means with each parts company and if they want a good repetitive business?
I have gotten lots of replacement mufflers and even got one more set of gas lifting springs for my wagons fifth door under those warranties. On colder days it quit holding the hatch open.
Both will have trouble withholding their gases eventually!

It can pay to keep these buggers running, if you see it that way. Just got to be more handy with a wrench than a wallet by keeping your receipts.
A word here, make a copy of them as they will fade away, but if it has its back up attached, there’s is no squabble.

I have been thinking more about the low power in the upper end.
It’s a little unusual for the AMM or a ECU to fail in these ways, if it’s running fine otherwise?

This might be a plugged up exhaust system….. like a muffler or a catalytic converter.
Check that out for sure!


Phil

Thanks for you reply The 510 ecu from what i read is for a 84 240 with heated o2. When i got my 83 someone was trying to diagnose a no spark problem and connected the braid of the neg cable for the coil and the center conductor right to the coil which shot 12v to pin 5 of the ecu burning the print between pins 5 and 11 and taking out the AMM at the same time.The AMM has been replaced with a rebuilt one and the cat is fine.Im thinking the mapping in the 507 is not the same for a non turbo

An old post in Volvoforums.com says 510 is for LH 2.1, not your LH 2.0. That makes a bit of sense not being in Bill Garland’s ECU table as LH 2.1 is quite rare and that table was mostly user contributed and not necessarily from Volvo sources. Best to check an authoritative source before ordering.

Not being able to get above 2700 is almost exactly the governed limit for being in limp home mode. If the 507 ECU can’t see things like the AMM and I believe also the O2 sensor then it will go into limp home mode and ignore sensor inputs. If your 507 doesn't see an O2 sensor when it’s expecting one then that might explain your symptoms. If you now pull your AMM connector to force limp home mode and it behaves the same then that would seemingly point the finger to it already being in limp home mode and confirm my theory.

It smells to me like you may really need a 503. If you can’t find one listed anywhere, maybe ask a local yard to reach out on the wrecker network for your year and model being available as a parts car somewhere.

Re. Phil’s comments. I can attest to Injection Labs being a quality source and if you can get their stuff through FCP with their lifetime guarantee then all the better, although you’ll pay a few dollars extra for the privilege. Check the fine print, I just now vaguely recall there may be an exception for Injection Labs stuff.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Well it stops running with AMM unpluged and the 02 is swinging from 400MV to 700MV.and to run good enough drive the timing has to be set at 30degrees

Also, if the original ECU has a fried trace, did you try repairing it with a soldered bridge? Odds of a component also being taken out are probably high, but you never know. If the burnt trace is difficult to solder to, you can always go back to the next component on the trace and tack a wire to a pin.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

i repaired the print in the 503 and no go

what does LH stand for

Left hand dummy me i need a RH because thats where my ecu lives,the right hand kick panel

"The 'LH' stands for German: "Luftmasse-Hitzdraht"" -- https://en.wikipedia.org/wiki/Jetronic

The 510 is not specific to the heated oxygen sensor. It is the one that will work in place of 503. IPD circulated the rumor that LH2.1 exists more widely than it does. Both 83 and 84 non-turbo use LH2.0 which then was called LH-II. The EFI 84 turbo used in a 7-series has adopted the LH2.1 spot before LH2.2 came out for the 240 in '85. Dave -- blame IPD for the disinformation.

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Art Benstein near Baltimore

"...real expertise is never appreciated. People would always rather muddle along in their own dim, blundering way than have someone else point out where they were going wrong--even if that other person is clearly brighter." -Jeff Lindsay

Art, speaking of getting misinformation from ipd, I’m betting you well remember the days before the interweb when the parts listings, tech articles and comments in ipd catalogues and their quarterly newsletters were a major source of information for Volvo hobbyists, as were the monthly/quarterly mailed newsletters from national and local Volvo clubs. I still have a large binder full of ipd stuff somewhere. You had to have purchased something in the past year to stay on the ipd mailing list if you were an international customer, a definite motivation for me to order Mann oil filters and air filters. Ipd sold the Bentley book and as well Grimshaw, which were a bit rich for my tastes at the time. When they started to sell Gerhardt’s Volvo Problem Solver and once had it on a sale I could no longer resist -one of my better investments, but I soon moved out of the K-Jet world into LH and was left floundering a bit until the aftermarket manuals slowly caught up. I depended on a few friendly indies and parts people willing to share what they knew. When the Alt.autos/Volvo Usenet newsgroup started up I was drawn to it immediately. I imagine a few old farts here still remember using the TCP Usenet protocol (NNTP://). When the Popular Mechanics (non-pro version of Alldata) CD came out in the ipd catalogue I jumped for it immediately. That really upped my game until some goofy little replacement for Alt.autos came along called brickboard.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

To get into limp home mode, don’t pull the AMM while running, I believe you need to restart. It shouldn’t be flooded, but I’d wait a good few minutes anyway. 30 deg is pretty serious to getting it running half decent. Any chance the ignition side is getting in your way? A badly worn dizzie or bad Hall sensor can give you all kinds of grief, also a weak coil.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

new cap rotor and hall senser