hi...
i have a 88volvo740gle-- low km. 1 owner.
for quite a some time i have been experiencing strange problem., that is when ever it rain heavy OR when ever we have high humidity and if i don't start whithin a few hours. my car won't start.
i had a same problem as we had lot of rain and humidity (meaning i did not start in last 36 hour. i went to start just now and it will not start)
i have a new battery. alternator works fine. belts o.k. lots of light on dashboard.
please some one point out some of the possible causes. i just read it could be fuel but fuel pump is working fine.
could it be spark plugs?
many thanks in advance for any help.

 

If the fuel pump is running, then it is probably not getting a spark. Attach a old sparkplug to one of the leads and wedge it against metal and get someone to crank the engine. If no spark, then the damp might be in your distributor cap or wires. They may be so old that they are shorting in the wet. If your plugs are ancient with massive gaps that will also make it harder to start. So change rotor arm, dizzy cap, wires and plugs if they are all very deterioriated. Also, I used to have a problem where if my O2 sensor got wet the car would die. Check the wiring is good to the sensor and the insulation is not perished. Wiring in the eighties cars was terrible with the insulation crumbling to the touch. Check also under the bonnet for water leaking onto wiring. The fact that high humidity causes the problem suggests wires/dizzy cap/rotor arm etc. Everyone forgets to replace their rotor arms, which do deteriorate, as do the dizzy caps and wires. Hope this helps

 

If it only happens when the weather is damp, start with the distributor and wires.
Old cracked wires and moisture under the cap can dull your day.
Ed