740 no start

Oct 10th, 2002, 20:35

My fathers 86' 740 GL has a very niggling problem. It will start and run fine for 95% of the time and then won't start at all. Problem happens when car is cold and is very inconvenient. The engine will turn over but refuses to start. It has happened to him a couple of times and happened to me today when i borrowed it to get to work. I went back to the car after work and it refused to start. I then went back 3hours later and it started first time. It has also been started by bump starting it in the past - any takers??

The car is 86' 2.3 carb (pierberg?) manual and has 154k on the clock. It also had the carb replaced a couple of years ago.

JP

Oct 10th, 2002, 21:19

When you say that "the carb has been replaced" was that like for like, or did you do the Webber conversion??

The pierberg on the Volvo was a poor choice of carb and created a lot of problems, one of which was the problem you're now experiencing... that of "no starty!!" The carb itself was prone to going porous or warping at the flanges. The pulldown unit was also a common failure and costly, it could be an area to begin with, as it provides the automatic choke function to the car, when it fails it means that the carb is weak and is unable to richen up during the cold weather or it can fail in the "On" positon causing it to flood!

My advice is to bin it (if it's not already done!) and convert to Webber, cleaner, crisper throttle response, more economical and....
a manual choke to boot!!

Hope this Helps:-)

Regards
Dave M

Oct 11th, 2002, 09:13

for what its worth I second Dave M's recommendation to get a Weber. As well as the good points he mentions, there's less festoons of wires & vacuum pipes round it, plus you can feel under your foot when the 2nd choke is about to open which means the decision to drive like granddad on just the first choke, or open the second one to burn petrol & have fun is a conscious one. I found that so long as you don't want rapid accelleration you can still acheive illegal speeds on the motorway on just the first choke.

BTW I never have starting trubble with the Weber, but did with the Pierburg.

Oct 10th, 2002, 20:35	#1
jpollard Guest Location:	740 no start My fathers 86' 740 GL has a very niggling problem. It will start and run fine for 95% of the time and then won't start at all. Problem happens when car is cold and is very inconvenient. The engine will turn over but refuses to start. It has happened to him a couple of times and happened to me today when i borrowed it to get to work. I went back to the car after work and it refused to start. I then went back 3hours later and it started first time. It has also been started by bump starting it in the past - any takers?? The car is 86' 2.3 carb (pierberg?) manual and has 154k on the clock. It also had the carb replaced a couple of years ago. JP

Oct 10th, 2002, 21:19	#2
Dave M Guest Location:	RE: 740 no start When you say that "the carb has been replaced" was that like for like, or did you do the Webber conversion?? The pierberg on the Volvo was a poor choice of carb and created a lot of problems, one of which was the problem you're now experiencing... that of "no starty!!" The carb itself was prone to going porous or warping at the flanges. The pulldown unit was also a common failure and costly, it could be an area to begin with, as it provides the automatic choke function to the car, when it fails it means that the carb is weak and is unable to richen up during the cold weather or it can fail in the "On" positon causing it to flood! My advice is to bin it (if it's not already done!) and convert to Webber, cleaner, crisper throttle response, more economical and.... a manual choke to boot!! Hope this Helps:-) Regards Dave M

Oct 11th, 2002, 09:13	#3
phil_uk Guest Location:	RE: 740 no start for what its worth I second Dave M's recommendation to get a Weber. As well as the good points he mentions, there's less festoons of wires & vacuum pipes round it, plus you can feel under your foot when the 2nd choke is about to open which means the decision to drive like granddad on just the first choke, or open the second one to burn petrol & have fun is a conscious one. I found that so long as you don't want rapid accelleration you can still acheive illegal speeds on the motorway on just the first choke. BTW I never have starting trubble with the Weber, but did with the Pierburg.

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