PLEASE HELP! my '86 760 turbo wagon (b230ft) has all of the symptoms of a faulty fuel pump check valve (hard starting and sudden stalls for several starts after sitting overnight or for extended periods of time) so i replaced it (the check valve). seems to be a little better, but it's acting quite a bit the same. after running for 5 or 10 minutes it's fine and will start right up and run again and again throughout the day. until then it will die suddenly and then start a little easier, drive a ways, die again...does this a couple of times until i can coax a few minutes of steady driving out of it, then it's fine. the problem came on rather suddenly about three weeks ago when i was cruising at about 40 and the rpms dropped suddenly a couple of times w/o car actually dying. i have been battling it since then.

recently replaced: short hose connecting pre-pump to fuel sending unit, the sock/filter on pre-pump, fuel filter, fuel pressure regulator, injector o-rings, spark plug wires and a couple of worn hoses. i also cleaned the throttle body not long ago. the thing runs great now EXCEPT for this very agitating little problem.

from my research of past posts, it seems the fuel pump relay is a possible candidate for my problem, as well as the hall effect sensor in the distributor? do my symptoms fall under either of these areas? i would really appreciate some of your experience and expertise!

i'm young and a first time volvo owner and really want to love and trust my volvo like many of you seem to, but it's been tough so far! please help and thank you all for a great site!

thank you all for sharing your knowledge. i wrote this message originally and now have a regular username. all of you who suspected the hall sensor were right on. i realized it was an ignition problem by the cars instantaneous dying at and so (already having replaced plugs, wires, cap and rotor) went to the local bone yard and picked up a coil, power stage, and distributor (along with a variety of trim pieces) for a wopping $10! distributor was the last to go on and solved the problem--cranked right up and hasn't died since!

i'm a first time volvo owner and a youngster to boot, so despite the frustration all this caused i learned a ton about my car, so MAYBE it was worth it. if nothing else i don't want to give the car up cause i've got so much time and $ invested now. it is a great vehicle though. i just hope it's a reliable one now!

thanks again for all of your suggestions. they helped a lot!

('86 760 turbo wagon)

Not sure if you are still having a problem. Swap out your balast resistor (sp) with another one. It should be mounted on your driver side, just above the battery. I had a similiar problem once and I bought a new one and I had my old car back ...since you have already put quite a bit of $ into your brick, try to just swap it with a good one and see if it does the trick.

Best Regards,

Anastasia
1986 740Turbo Wagon 385,000 miles

thank you all for your helpful input. i just replaced the fuel pump relay to no avail. it sounds like i need to spend some time doing a thorough diagnosis to figure this out since throwing money at it obviously isn't working. i'm really hoping it's not the hall sensor--i've never done one, but it sounds like a very complicated job!

the problem has gotten worse--hard starting every time now, not just in the mornings and after it's been sitting for a long time. it really seems like it's a fuel starvation problem because i have to pump the accelerator a LOT to get it started and that's the only thing that seems to work. we'll see what i can turn up in a long volvo saturday tomorrow.

i'll keep you posted. thanks again for your help! this really is a great thing you've got going here.

I think you definitely have either bad hall sensor or bad FI relay symptoms.

The FI relay is cheap and worth having a spare in the car just in case. The hall sensor is a bit more expensive to replace if you want to do it on the cheap by reusing the old distributor.

But at this point I would advise you to take a step back and stop buying parts and do a more thorough diagnosis. Pick up a copy of the volvo fuel injection manual... TP31140/2 through www.volvotechinfo.com (TP31140/2) is for the B230F, but they also have one for the B230FT (TP31451/1) for about $25 each. YOu can sometimes find these on Ebay for cheap, but www.volvotechinfo.com is reasonable and has fast shipping.

These contain a complete step-by-step fault tracing guide for diagnosing engine problems. It proved a life-saver (and $$ saver!!!!)

I also picked up the ignition manual (TP31397/1) which also has a step-by-step fault tracing guide as well as complete description.

The only requirement for doing your own diagnosis is patience and a digital voltmeter (DVMM). A timing gun and a fuel pressure tester are required as well.

Think about it. :)

Mike

"the rpms dropped suddenly a couple of times"

this is symptomatic of faulty wire from hall sensor.

This happened last year on my '87 740-- it seems like I changed everything but the door locks before I got to the distributor. My advice is to find a FPR from a junkyard (~$5) and try that. (Buy all the relays if they're there!) Get the engine good and hot, shut it off and try to restart it. If it starts you may have solved your problem. If not, pull a new distributor-- forget about fixing the old one unless you have the time and expertise to do it (I don't)-- and install it in yours.
My junkyard distributor came out of an 86 sedan and it was a supreme pain in the @$$ to get it out. I had a helper and we had to pull off everything up to the timing belt before wedging the distributor out. Be careful-- that Hall connection is fairly fragile.
This should fix you right up. If not, the Hall will go out eventually anyway, and you'll already have your spare.
(BTW: I was charged a total of $100 for a starter, distributor, the entire relay board, AMM and the in-line fuel pump.)
'85 240 223k (R.I.P.)
'87 740 Turbo 213k

If you have a consistent starting problem, you really need to start by identifying whether the culprit is lack of spark or fuel.

Check the FAQs on how to test these. Here's a link you can start with.

http://www.brickboard.com/FAQ/700-900/ElectricalIgnition.htm#CarWontStartIgnitionDiagnosis

one more note: i can hear both prepump and main pump buzzing with key turned to position II, but the main pump doesn't turn off after several seconds like i understand it should.

thanks again all.

my '87 740 wouldn't start, period, but the fuel pump ran for minutes on end, even with the keys taken out--a new fuel pump relay was the main trouble in that case.

--'87 740GLE to 207000, '90 turbowagon at 157 going on 300...