Hi:

ADDENIUM to the note below and thanks so far for many of your helpful tips:

Since the note I have replaced the fuel pump relay: That did nothing to correct the problem.

But, I think I am closer to isolating the problem. Last night after trying to start the car at five-minute intervals and just before the tow truck arrived I decided to try one other thing. I turned the ignition and just left it on for about 2 minutes then tried to start it and I could tell I was very close to victory. But it would not start. I left the ignition on for another minute and tried again and it instantly started just as the tow truck pulled in. It seems to me logic dictates there is one or possibly 2 components working together to cause the problem but for someone who knows this car can probably point to the cause fairly easily given these facts. Obviously the problem needs to be corrected, as this would create some difficult especially at a stoplight.

Original Note:

Re: 1987 Volvo 740 GLE (non turbo)

Problem: Will not start on an intermittent basis (not as intermittent as it might seem on further effort as described below:

Action taken thus far:

Had it towed 3 times to 3 different mechanics the last time to a very knowledgeable Volvo mechanic.

The first 2 mechanics gave up because ever time they tried to start it, it worked perfectly.

The 3rd kept the car for five days --- tried numerous times and it always started --- he let it run for various lengths of time up to 4 hours once and could not get it to fail to start. I picked the car up drove it for 20 or so miles into my drive way ---- shut it off and ten minutes later tried to start it and it just kept turning over with no results pushed it in the garage and left it over night --- it immediately started in the morning --- I drove it 2 miles and parked and just for kicks tried to start it and again got the same no start results --- 2 hours later it started up right away --- drove it for 15 or so miles and turned it off --- tried to start it and it fired up right away at 5 and 10 minutes interval up to an hour.

Fuel Pumps Work ---- get spark --- battery fully charged.

Sorry I didn't notice that you indicated that you are getting spark and reference to David's question- are you getting spark during the no start situations? Is it strong, blue white spark that will jump a good gap or just mediocre. If you are getting a good spark you should be able to spray starting fluid into the intake and have it run momentarily(remove hose on the throttle body, spray fluid in for 3-5 seconds,quickly replace hose and immediately try to start it). If it will run on the starting fluid this would indicate a fuel delivery problem. Also I'll mention that your car is not equipped with a radio suppression relay.

Randy

Unfortunately an intermittent problem can be the most difficult to diagnose. You say that you have spark. Do you mean you have spark during the actual no start period? During attempts to start during a no start incident does the tach nudge up slightly as you crank? If yes then your hall sensor is producing a signal.
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David Hunter

You haven't mentioned the radio suppression relay/aux fan relays in engine compartment. Well documented source of intermittant starts. The relays are the same, I would just swap to see if problem is solved. Also, you said you replaced the fuel pump relay. the relays rarely fail, but they do get cold solder joints- resolder first!

If you have had the car to three different mechanics and none of them have suggested the distributor/Hall switch I am surprised. The easiest way I know to check that possibility is to swap out a known good distributor, but that may not be an option in your case. At the very least when the car won't start next time GENTLY wiggle the wires at the distributor connection and see if it makes a difference. Changing out the switch in your distributor is an option but my experience is that removing the pins in the shaft is difficult at best.

If you have a pick and pull in your area and it is above zero you might consider pulling a distributor off of a car there. Most places will refund your money or at least give you a credit for your next trip if the part you get is defective.

Be careful of stressing your wiring harness too much as unfortunately the model year 87 is usually equipped with one that is degraded with the insulation easy broken off of the wires.

Your car does not have an RPM Sensor (which would be a much easier repair than replacing the Hall switch). Good luck.

Randy

I had similar symptoms, in my case it was the rpm sensor working intermitently.
Everytime i had a no start problem,i went into the hood and played with the wires etc. and then try to restart.
good luck.
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jlp

the 87s did not have a speed sensor that reads the flywheel, those came out with lh 2.4 sometime in 88. chuck.

Try some of the stuff on this page:

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

Possibilities that come to mind are the Hall sensor wiring, and coil.