Fuel presure @ idle is 70, reg connected with new regulator

Sounds like a bad fuel pump to me.Or dirty fuel lines/injectors/regulator.

CHECK THE JETS , YOU HAVE GAS PRESSER BUT YOU COULD HAVE MAYBE JET PROBLEMS AND CHECK AIR HOSE'S.

------------
GAS-------INTO-------JETS---into---------ENGINE-----LOW RPM
-------------

check the fuel presure switch or (regulator)

clean connections on regulator .....replace hot cable if needed might try jump across reg. if u know how

Sadly Nikkidaly...

It could be ANYTHING from a glove-box light to
a trunk switch...

I had an '86 535i... (I hate those fuses (sorry)).

My only caution against poking around in your WIRING
is that there are TRIGGERS for AIR-BAGS.

If you do not have FACTORY drawings
(I highly recommend) FREE drawings for "popular"
USA market vehicles can be found in the
BBB Industries website (registration is required).

It is a tedious process... and changing out
in-necessary parts is more likely to CAUSE
more TROUBES than to fix them.

If you seriously think it is an OVERDRIVE relay
find and pull that relay (lots of cars don't have
OVERDRIVE...

Then GET SERIOUS about finding the
"CURRENT DRAW"... (3 days to run down
a NEW car battery is a decent draw).

An AMP-METER and a FUSE PULLER would
be a great start... (one at a time)
(or use a volt meter and check for fuses
that are showing SLIGHTLY LOWER voltage).

Check out the fuse kit at AMAZON
(my local auto parts store was OUTRAGEOUS)...

Relay
http://www.rockauto.com/en/catalog/volvo,1983,244,2.4l+l6+diesel,1287491,electrical-switch+&+relay,overdrive+relay,3624

Fuse kit
1983 VOLVO 244 2 4L L6 DIESEL Fuse RockAuto

Hope this helps.

Carnac the Magnificent

Check fuel filter,if ok the pressure regulator may be bad.Check vacumn line to the valve! Must have vacumn.At Idle!

i think i would check the fuel presure regulator and the fuel presure if fuel presure low look at fuel filter if rail not holding presure then look at fuel presure reg and vac conection on it

check the fuel presure reg but first check fuel ammount place fuel line un hooked in 1 galon glass jar turn ignition to run position container should fill quickly mesure fuel amount from single cycle call dealer ask what flow amount should be with single purge cycle
this will tell you if pump or filter are problem it will allow you to see if fuel filter is pooched and **** is bypassing also or if it is pluged

if results proper or close to dealer spec check fuel rail for bad fuel presure regualor if reg bad there will be little or no fuel presure even during purge cycle if flow high and finger cant hold presure if is usually fine and reg is bad pick up new reg from salvage it will cost 5 - 20 bucks and if a likely culprit

there is a fuel rail on your motor in the fuel rail you will find a cap it looks like a tire valve cap
some cars black plastic some light silver metal
find the cap and take it off push down on the schrader valve to see if you have fuel preasure b4 you start changing parts
if it has fuel but it isnt a huge amount
check the fuel presure reg

by having a friend turn on the ignition and while they do that push the valve down if huge fule ammount or huge presure then start looking at the FPR
if it has good or a lot of presure then start by checking the spark
if you can borrow an obd2 tester canadian tire loan a tool and you can borow eithor cheep or free from them
remember you have friends too so dont for get to ask if they have or hnow anyony who might have that you can borrow it

I just went through lots of troubleshooting and expense on my 1996. Whenever I would lift my foot off the accelerator and was below about 30 mph, the rpm's would starts jumping around and sometimes it would stall. If I gave it a little gas (accelerator), I could sometimes keep it running. It also backfired once in a while. Starts right back up. Also, if I let it idle while in part, it would die after 1-2 minutes.

I ended up finding a hole in the fuel regulator. About a ~$70 part if you get an AC Delco, but very simple to change.