a Fuel Pump Relay
a Bosch K-Jetronic equipped 200 series Volvos
Fuel pump relay
Volvo owners have experienced starting problems or break-downs that
were caused by fuel not getting through to the engine.
new fuel pump assembly might be an option if
the problems have become extreme.
Most of the 200 series Volvo with Bosch K-Jetronic Fuel injection have
an auxiliary in-tank fuel pump and a main fuel pump controlled by
a fuel pump relay.
The most common causes of no-fuel supply are:
- Blocked fuel filter
- Faulty Fuel pump –
- Faulty Fuel pump Relay - electrical
- Blown fuse or bad fuse contacts - electrical
The in-tank pump has a filter which can be
cleaned by removing a small lid in the top of the
tank from the
boot, the whole
pump unit can be lifted out of the tank carefully
and the filter can be checked and cleaned if necessary.
The main fuel filter is mounted under the bonnet on the firewall
and has to be replaced every 40,000kms.
ipd ss fuse
However, most of the no-fuel problems are caused by electrical
I have had a breakdown with my 240GLT once because of no-power to the
fuel pumps caused by corrosion
on the fuse contacts in the main fuse board. My wife later had a similar
problem with her 244GLE and I knew directly what the problem was
when she rang me - fuse corrosion. I made it home after cleaning the contacts of the fuse supplying power to the fuel pump.
As a preventive maintenance, I have
replaced all my fuses by glass fuses with stainless steel contacts
and that was the end
of the fuse problems.
The main electrical no-fuel problem is the actual Fuel Pump Relay. The
green relay is installed on the left side in the car under the
dashboard where it can get very hot and causing bad solder joints
inside the relay unit, also contact resistance built up over the
years may cause extra heat and the ageing of the relay.
The relay is of the plug-in type and can be taken out easily, pop
open the plastic casing by prying the case apart so that the end
with the connector slides past the retaining wedges. This is a
little bit difficult, but can be done without damaging the unit.
In most cases the bad solder joints can simply be re-soldered. Even
if you do decide to replace the relay it may pay to fix the old
relay and keep it in the car as a spare, it could save you a lot
Location of relay
1988 240GLT (RHD)
Fuel pump relay
Another relay causing some problems is the O/D relay on 4-speed
Auto Transmissions in the 200 and 700 series. This relay is
operated by the push button on the gear lever. If you cannot
control the 4th gear (orange arrow on dashboard on/off) this relay
may be faulty, most probably soldered joints. This relay is located
in the central console behind the ashtray, a bit tricky to get to.
FAQ Fuel Pumps
from Dave, NSW, Australia (Dec2006)
I found your web site while searching for information to help me with some problems with my 1983 240GL. Congratulations on a great looking web site with heaps of useful information on it. I thought my recent adventure with the
fuel pump relay AND the ignition system (simultaneously) might be of interest to you and may be of help to others.
The engine stopped while driving and would not restart. On turning on the ignition there was no action from the fuel pumps, so I pulled the cover off the fuel pump relay. I could see that the relay was not pulling in when I turned the ignition on (normally it should pull in for a second or so when the ignition is turned on to pressurise the fuel system). Pushing in the relay armature with my finger made the pumps run, so I thought if I jammed the armature closed I could get fuel pressure and get mobile temporarily. But it wasn't to be - the engine still would not start.
I found there was no spark from the ignition coil, and putting a test lamp on the coil primary and cranking the engine showed there was no drive from the electronic ignition unit. The distributor was rotating OK and there was 12V getting to the coil and the electronic unit, so it looked as though the reluctor coil or the electronic unit was faulty.
At this point I decided that this was too much to handle by the roadside, so I called my motoring organisation. They came out, had a look, came to much the same conclusion as I had, and arranged a tow.
With the car back home I pulled the fuel pump relay unit out. It is a Volvo unit, with markings 12V 89 6369 1 323 152. I tested every component I could and resoldered every joint that looked even slightly suspect, but no good. Try as I might, I could not find why the relay would not operate. Since I had run out of ideas there, I decided to look at the ignition problem.
The electronic ignition is a Bosch unit with markings 0 227 100 018 12V. To test the main power transistor I unsoldered the flexible leads going to it from the printed circuit board, and it was here that I found a problem. These leads consist of short pieces of metal foil. I had unsoldered them at the transistor end and thought one of them felt loose at the board end. Removing the board revealed a classic dry solder joint. It looked like it had been that way since new, but apparently had made reasonable contact until now, although I wonder about how many subtle problems it has caused over the years.
Bosch 0 227 100 018 12V Unit in situ (front right hand side of engine bay of 245GL Australian model
||Dust cover slid off.
||Unit removed from vehicle and snap-on cover removed. (Note that I have marked the functions of the main connector pins. They are (left to right): 16: no connection, 16: output, 31: ground, 15: +12V, 31d reluctor ground, 7: reluctor active. Note that there are two pin 16s! I believe this is just to confuse us!).
||Close-up of connections to main power transistor. In my unit it was the emitter connection (uppermost connection in photo) that had a bad solder joint under the circuit board.
I re-soldered the lead and put everything back together. Expecting to get ignition now, but to still have the fuel problem, I was amazed that the fuel pump relay now operated normally and the engine started immediately.
I think the system works something like this: when the ignition is first turned on, the relay pulls in for about 1 second then drops out. This is achieved by a timing circuit around a 555 timer IC in the unit, but there must be a low (about 1 volt) on terminal 31b of the relay unit for this to happen, brought about by the ignition unit output being low at this time. (Terminal 31b is connected directly to the ignition unit output/coil primary). When the engine is cranked over, the relay pulls in again and stays in while ever the engine is running. The mechanism for this is circuitry between terminal 31b and the 555 which detects pulses from the ignition unit output and causes the relay to remain operated while the pulses are present. In my case, because the power transistor in the ignition unit was effectively open circuit, the ignition unit output stayed
permanently high, the initial timing sequence would not happen, and the relay would not pull in while the engine was cranking.
Dave Pike, NSW, Australia.
Feedback from Mick Cook from Australia (April 2007).
Hello Jim, Great web site. Great article by Dave Pike.
Just cured a problem with my 82 245 K-Jet which was similar to Dave's. This may help someone.
Have had intermittent start probs for a few months. A good second hand heavy duty battery righted that for several weeks - then the "I'm not going anywhere" hit.
Had already stocked up on a good tank and pressure pumps, firewall mounted filter and complete fuel line from a wreckers, just in case.
I live in an environment with high background noise so I couldn't tell if either pump was on or off.
To test I removed hose to inlet of pressure pump (under floorpan on cradle below LH rear passenger seat) and routed it into bucket. Ignition on produced about 2 litres/min at about 2 to 5 psi. GOOD, this means in-tank pump performing as required.
Remove firewall mounted filter and connect hose (used fuel line from wreck) to filter inlet side of supply line to collect fuel from supply line, catch fuel in bucket.
Ignition on produced NO FUEL. Try starting to see if pressurising fuel pump might make fuel under no load. Still NO FUEL. Jiggle wiring to pressurising pump. Still no fuel in starting mode, at filter position.
Remove pressure pump and accumulator on cradle to test and to renew cruddy wiring job from distant past....(does this mean somebody has been down this road before on this unit?). Repair wiring loom (hot wire and ground join onto main loom inside car, under seat and above cradle) to pump and re-terminate pump wires to loom.
Use removed short loom to test pump and accumulator off a battery. BEWARE, this test is DANGEROUS if proper procedure not followed - fuel and sparks result in combustion. Use jumper leads clamped (with small multi-grips or similar to provide strong connection that will NOT SPARK) to the loom ground and to an inserted female spade connector to the loom live (or active) wire, which is yellow on my case.
Connect 1/2 metre of 5/8 inch (if I recall correctly) fuel line to inlet of pump and drop free end in a bucket with a few litres of fuel.
BTW, I've found fuel in the open tends to be less explosive in combustion than in a closed container - hence the bucket. NO SMOKING!!! If there isn't a short supply line hanging off the end of the accumulator, connect up some line there to take fuel back to the bucket - or any other bucket will do. Sit the cradle on a plastic milk crate and prepare to activate pump off battery (which is min. a metre away).
Activate pump - works GOOD, great flow. No awful noises - whirring away beautifully.
How about pressure? Connected up my irrigation pressure and flow tester to accumulator outlet. This device is for water, but what the heck, it's all incompressible liquid with similar viscosity. Pressure test showed about 130 psi on my gauge. That's GOOD. Accumulator doing it's job too, NO BLEED-DOWN from 30 minute static test other than a few pounds lost through a weep on the gauge plumbing.
So I now know that mechanically the fuel delivery is just fine. Refit cradle and reconnect fuel lines - test for delivery at filter again. Still NO FLOW even with engine cranking. Aha - found relay and it RATTLES. Yes, I removed green coloured relay from position near fuse-box and it rattles when shaken. That's not right. I love these Volvos. You can unclip relay cover and have a look! Ah yes - obvious problem. Armature cradle loose on circuit board - shakes, rattles (and no it doesn't roll) when I shake it. Can see on other side of circuit board how solder is no longer bonded with 3 posts on armature cradle. Solder 'em up. It's easy - the procedure is keep heat of iron on post and feed fine resin cored wire to where break is. I found an 80 watt iron was about right. Be patient and careful.
Refit relay and test. Yo bro! Have fuel flowing from filter inlet pipe when cranking in start mode. RELAY now GOOD. Refit filter, but not with Bosch monster I found on my firewall. Used a smaller diameter unit off a wreck - seems to be less restrictive (I blew through them both) or was the old one becoming blocked? Never broke it open so don't know how it works.
I digress - ignition on, starting starting YES! SHE'S A GOER!!!
A word of warning - that green relay will, if it ain't workin', will create all sorts of bother that will have you exploring engine compartment electrics and all. Good idea to have a spare one handy just in case. I have one now - got it from the wreckers for $6 and it also had a rattle; so I fixed exactly the same problem as the one now running. It tests OK now.
I wonder - was that very straight car I removed the relay from in the wreckers because it had died due to a dead relay?
Mick Cook from Australia.
'82 245 x 423k and still strong
Feedback from Liz
Hi Jim, It worked! I walked up to my car this morning and took out Fuse #13 (the one that controls the relay to the fuel pump and my indicators) and sure enough it was all corroded. Not badly, but enough that I could scrape off some black stuff. I "shined" it against (of all things) my dashboard cover and replaced it. TA DA - My car started. I carefully drove it home (my unit is on the side of a hill - one road home is less 'hilly' than the other) and left it there all day. I bought some new ceramic fuses on my way to work and after work, I called my mechanic back in Perth (have moved to VIC, but this guy's looked after my car since it was NEW if you can believe it or not) and he just said "yes yes yes". So it was totally the fuse, which I have now replaced.
Thank you SO MUCH JIM!!!!
Liz Aitken from Victoria, Australia
Feedback from Richard Ford
I have been having fuel pump problems for a few months with my 1990 240. It just wouldn't start one morning and I saw that it wasn't getting any power to the fuel pump at the fuse panel. I jumped the wire to another fuse outlet and the car started. It would run ok, but was always hard starting. I found out that my intank fuel pump wasn't getting any power to it. Only the external fuel pump was working. The pump was ok, just not getting any power. It ended up to be the computer ECU unit. It wasn't sending the correct signal to the pump. I got one at the junk yard and it now starts as soon as I turn the key.