1990 240 intermittent no start/rough cold start

abracadabra · Post by **abracadabra** » 02 Dec 2010, 12:32

THE STORY:
Every morning, I go out to my not-so-trusty 1990 Volvo 240 and turn the key with trepidation, unsure of whether or not it will start. If it does start, I drive to work, wondering if I am making a mistake and should really be going to the mechanic's shop instead. If it doesn't start, I call a friend to give me a ride, and do some troubleshooting while I wait. I know that when I come back from work in the evening, chances are it will start after a bit of cranking and my opportunity to find the root cause of the problem will be gone. Initially, I did enough diagnosis to determine that it is indeed a fuel/mixture problem...it started with starting fluid. I replaced the fuel pump and fuel filter and fuel fuse holder and fuse (near the battery). The car started, and I was overjoyed, but over the next few days, I realized that I had not fixed the root cause of the problem. With the same symptoms leaving me stranded and in need of a ride yesterday, I had the chance to do some more diagnosis. Removing the fuel pump relay and jumpering from the red/yellow wire to the red wire, effectively forcing the fuel pump to run constantly, made the car start and run normally. Replacing the fuel pump relay did not.

THE SYMPTOMS:
Intermittent no start, when cold. It always starts when I go back out to the car after errands, and the engine is still warm. When it does start, it typically has an oscillating idle for the first minute or so, before smoothing out to the sound of a good Volvo engine. Even when warm, it will miss a few times just after starting. It starts just fine when a mechanic is with me, even if it is cold.

THE CLUES:
Replaced fuel pump, fuel filter, fuel pump relay, fuel pump fuse holder and fuse.
Forcing the fuel pump to run constantly by jumpering wires at the fuel pump relay causes the car to start and run as it should.

THE QUESTION:
I'm stumped as to what to check next without just starting to replace parts. Does anyone out there have pointers on what to check next? I'd prefer to diagnose the problem rather than breaking the bank replacing parts.

Post by **billofdurham** » 03 Dec 2010, 12:36

Welcome to Matthew's Volvo Site.

My question - which fuel pump did you replace? Oh yes, and why?

You have two fuel pumps - one main under the car and an in-tank pump which acts as a priming pump for the main. Before jumping in and replacing either pump you can usually hear if one or both aren't working. To check the in-tank pump remove the filler cap and listen at the filler opening whilst someone switches on the ignition. You should hear it run momentarily. To check the main pump you can listen or put your hand on it, again whilst someone switches on the ignition.

Bill.

kwaykuul · Post by **kwaykuul** » 19 Dec 2010, 16:02

Hi,i have a 1993 240 and am having the same problem as abacadabra had...car wont start when its cold.
i put in a new fuel pump under the car and the car worked fine for a few noncold days
but then its stopped working again now that its cold. The main fueI pump still works fine.
I know it works fine cos i can hear it momentarily
when key is turned and also i gave it direct power from a battery and it
was running like crazy

However, after a lil research on here i notice that my intank fuel pump doesn't work.
Had my lady start the car whiles i listened at the filler as instructed by bill, and i didnt hear it running.
Am guessing that since thr main pump works the relay should be working fine and that the
problem may be an in-tank one. Any suggestions please? Am desperate for help.
Also how do i locate my fuel pump relay?

Post by **billofdurham** » 20 Dec 2010, 11:41

On the 240 the fuel injection relay is behind the right side of the dash. The attached shows the locations of most of the relays in your car.

240 relays.pdf: (1.18 MiB) Downloaded 626 times

You can access the in-tank pump through an inspection hole in the floor of the luggage area and you could give direct power to it as you did the main pump. Also check fuse #4 which is for the in-tank pump.

Bill.

andys240 · Post by **andys240** » 22 Dec 2010, 21:35

i just updated my post about a similar situation, but i have been using heet the last tank and a half and its been starting first time every time, good luck!