Login Register

86 740 No spark, fuel pump doesn't turn on unless push relay Topic is solved

Help, Advice, Owners' Discussion and DIY Tutorials on all Volvo's "mid era" rear wheel drive Volvos.

1975 - 1993 240
1983 - 1992 740
1982 - 1991 760
1986 - 1991 780
1990 - 1998 940
1990 - 1998 960
1997 - 1998 V90/S90

Post Reply
JohnG

86 740 No spark, fuel pump doesn't turn on unless push relay

Post by JohnG »

I'm working on a 86 740 4 cyl, no turbo. Cranks, but won't start. Would occationally, apparently randomly, work fine for 10 minutes then fail. Hasn't even done that for a while.

The fuel pump doesn't go on, but will if you manually push the relay. (I took the cover off the relay). The lamda sond (or whatever it's called) relay right next to the fuel pump relay does engage on its own.

There's no spark. I removed the distributor and the HAL sensor was very dirty and oily. I cleaned it well, but that didn't solve the problem. The distributor does spin.

I assume it's the coil or the HAL thing in the distributor. I couldn't figure out anything else. We're on a very tight budget at it would be nice to close in on the problem before buying parts.

Can I test the coil by putting voltage across it to manually generate a spark? Can I test the HAL thing some way?

I can get a coil for $5 or so at a junk yard and a whole distributor for $25. Sounds cheap, but if I could know the problem first, then it would be worth it. $25 on a guess will hurt.

Anyway to test those items, or maybe something I didn't think of?

Thanks,

John

JohnG

Post by JohnG »

Oh, and the tach "jumps" when you first turn the key.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post