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AQ131D Starting/Running problems

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wayne4123

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I have a Volvo Penta AQ131D with starting/running problems. Sometimes won't start at all then go back 30 min. later and it starts. When warm and accelerating under load it will sputter and die. After running a short time and turning off it will not start usually for at least an hour. I have changed the coil, points, condenser, rotor, wires, spark plugs, distributor cap. We have checked the gap and timing and everything is right on. When engine won't start I look inside the carburetor and it is getting lots of gas but when I pull a spark plug it is dry. It seems like the gas is not getting to the cylanders. I have been having these problems for the last year and a half and even the local boat mechanic is scratching his head at this point. I had it in the shop where they lifted the valve cover and everything looked okay. All timing was reset, water pump was changed, distributor reset and carburetor rebuilt. I had installed an electronic ignition but the mechanic took that out again. Any input would be much appreciated.:)
 
First, why did the mechanic take out the electronic ignition? Unless it was faulty, that's a dumb thing to do. And if it was faulty, I would have replaced it with another electronic ignition kit... NEVER with points in today's day and age.

If I were you, I would re-install the electronic ignition kit.

Now let's look at your problem. The first thing I would do (for test purposes) is hotwire the + of the coil with a lead coming from the + of the battery, then attempt to start the engine. If it starts, but then it dies or does not start without the jumper, then you may be dealing with a defective ignition switch or faulty wiring to the coil.

If that is not the problem, there are a number of things you should look at:

1) Make sure you have the idle mixture set correctly in your carb. In the early version the screw is supposed to be opened about two turns, but the late version is supposed to be 9-1/2 turns open.

2) Make sure there is a good ground between the distributor and the engine block, and that the ignition wires go to the correct spark plugs.

3) Make sure the anti-syphon valve in the fuel tank pick-up tube is not stuck.

4) Make sure the accelerator pump is working in the carb.

5) Make sure the engine is not flooded after it dies. For this, attempt to start with the throttle lever about 75% open, then be prepared to bring it back to idle once the engine starts.

6) Make sure the timing belt is correctly installed and it has not jumped a tooth (or several). If the valve timing is off, the engine will perform poorly or will not start at all.

7) Run a compression test and a leak-down test. The former will indicate if compression is adequate and balanced, and the latter with tell you where your engine is loosing pressure (valves or piston rings).


I hope the above will help you to troubleshoot the problem.
 
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Thanks, I will check these things out. The carb in my boat does not seem to be the original carb. I ordered a carb. kit for AQ131D, 18-7000, and the idle jet screw and the float valve did not fit my carb. Neither Sierra Marine nor Marine Engine have ever heard of this part not fitting an AQ131D and tell me my carb must not be the original. Identifying it has been impossible so far. On the carb cover is stamped 131A with these numbers underneath it 61186 16 0 01. On the base of the carb is stamped 70795 16 0 01. The carb kits are supposed to fit all AQ131 series?? Very frustrating. I can go back and try the screw both ways.
 
Wayne, you are not the first person having this problem. There are two different sizes of idle ixture screw and the latter (yours) is apparently narrower and shorter than the one coming with the kits. Please send me a PM with your e-mail address and I will try to send you some additional information.

Not sure if this is the one you are looking for, but if you contact the web site and include the dimensions of yours they may be able to belp.

http://www.carburetor-parts.com/servlet/the-196/solex-idle-mixture-screw/Detail
 
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Thanks for the referral. My idle mixture screw is the thinner one but it does not have a collar on it like the picture of the one for the 44PAI, it looks more like the Holly one. Strange. I will have to remove it to get a measurement and take a picture.
 
I also am having a problem finding idle mixture screws for my 44PA 1,it is the later model and the screws are smaller.Any help locating them would be greatly appreciated.If I can't find some I don't know what other options I would have?
 
wap41, my inability to find the idle mix screws you are referring to is one of the main reasons I switched to a Weber carb.
 
Okay, have tried all of the suggestions and everything has checked out okay but still gas to carb but not to cylinders. As I said before when I pull a spark plug they are dry. The mechanic seems to think it may be hydraulic lifters sticking. He has tried everything else. Actually, after removing the distributor and cleaning it up and reinstalling it and then removing the electronice ignition and reinstalling the points system the boat would turn over but not start. Getting good spark and gas puddled in bottom of carb but none seems to be going to plugs and just won't catch.
 
Have not had a chance to check the idle jet screw yet but the picture of idle mix screw in thostorey's reply looks to have a collar and mine doesn't but I will check it out. Saw what looks like maybe the one I need in a VW universal solex carb rebuild kit. Will have to contact seller of kit to see if it is what I need.
 
Are you sure the timing belt is correctly installed? If the gas does not reach the cylinders but reaches the carb, it could be an indication that the timing belt has jumped. You may want to take a compression test and see what compression you get. If too low or zero, then you likely have a timing belt problem (jumped, broken or incorrectly installed).

BTW, your engine "lifters" are not hydraulic, and they are commonly referred as "buckets" or "cam followers" (the OEM referes to them as "valve pushers" or "valve tappets"). Hydraulic lifters are installed on the DOHC models (AQ171 and the 251). The cam followers in your engine are not notorious for sticking, and I doubt very much that all or most of of them would stick at the same time.
 
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I bought a volvo 230b and also have some trouble getting it started. Its firing and almost runs. It now has a new electronic ignition, wires and plugs. Lots of spark. The carb is also full of gas and has flooded the intake manifold. But the plugs are dry all the time???? I have the carb off and everything is clean and seems to be working. Any ideas on what I should try next. Thanks in advance.... dennis123
 
Sounds to me like you are dealing with a fuel quality issue. I had bad fuel and had the same symptoms. Luckily I had 2 tanks and was able to switch tanks to verify the problem.
 
I replaced the timing belt on my 230b. All three marks on the shafts are correct according to the repair manual and the firing order is right. How do I know which is # 1 spark plug on the distributer cap. Still trying to get it started...... Thanks
 
89 Baretta with aq131d, had same problem starting it. Wet manifold, dry plugs, ect. When I hooked up my battery charger and switched it to engine start amps, things sarted coming to life. I found it needs to spin fast, try jumping it, or two batteries. It's still tricky, but it fires a few times until it catches.
Thanks,
Dale
 
Hi, if You has not solved Your problem yet, the problem can depends on that the needle valve above the floater has loosen. I have seen this problem earlier on cars and the symphtoms were similar.
 
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