i have just recently bought a 1988 volvo 740gl turbo and i was driving it the other day only done 10km when it stalled as i came to a stop at a set of traffic lights and wouldnt start... i left it there for a hour or so then came back and it started and i drove a few kms home.. car hasnt moved since!! what would this be????

 

could be almost anything. fuel pump relay, ignition wiring, hall sensor, or something else.

 

so i am gonna go ahead and say not a common problem?? haha thought it might of been a easy fix ie. blown fuse/relay...

its getting fuel, has strong spark, injectors are new, leads are new... havnt checked relays?? but if it were relays would the car start again??

i have been a ford man my whole life and just jumped on the volvo band wagon! and want to get this machine up and running but i dont have a strong volvo understanding.....

 

well, relays can fail intermittently.

are you sure you had spark and fuel when it wouldn't warm-start ? intermittent problems are a bear to diagnose.

 

yer had fresh spark plugs i pulled aone out grounded it and turned it over all good... it doesnt like warm starting.... my first issue is why it stalled in first place then second problem is why it wouldnt start..

i did some resarch the fuel pump relay is behind the dash ill replace that and go from there that hopefully will solve my re-starting issues as for why it stalled could that be a relay as well??

yer intermittent issues are the worst especailly if there electrical!!!

 

on a 740/940, the relays are behind the ashtray, in the back of the fuse panel. if you remove the cigar lighter/cubby above the ashtray its a lot easier (unsnap plastic bezel around cigar lighter socket, and there's 1-2 screws, pull those, cubby comes out, easy access).

I wouldn't just replace the relay without doing some tests to prove its the actual problem

when it won't start, pull a spark plug or two... if they are wet, then you got fuel, and probably no spark. if they are dry, you probably aren't getting fuel.

 

thanks for all your help ill source a relay and replace the old one and go from there! as the only annoying way to test it is go driving and see weather or not i break down !! then i can pull put the spark plug and see !! cheers..

ill get back to you with proceedings!!

 

I'd start with the Hall Sensor: check the wiring and possible oil contamination of the sensor.

 

where is the hall sensor? and what is it? and what does it do?

sorry fot the questions just want to get up to speed with everything so i can get this beast going!!

 

LH2.2 cars have the hall sensor in the distributor. it provides the timing reference signal that both the ignition and fuel injection use to know when to spark and how fast the engine is turning.

on LH2.4 cars (90+ turbos, 89+ non-turbos), the hall sensor was removed and instead a crank position sensor reads notches on the flywheel between the engine and transmission.

 

Hall sensor was my first thought too, though all other suggestions are good ones. But that is what stopped my old 740T cold. But, my failure was all at once, and it was dead, dead. Nothing intermittent about it. My guess is if the hall sensor is a problem, it may not be the sensor itself, but the wiring leading up to it or the plug.

 

Actually it failed a few times and then after a few episodes it would never start. As far as I know Bill's fail all at once. This is all referring to zjinqui1k's post about the hall sensor as far as I remember it.