Volvo expert needed

FENIXX3435 · Aug 12, 2004

Volvo expert needed

I have a 1990 Volvo Penta AQ131C 4 cyl. I have replaced the Coil, the wires, plugs, points, condenser, The distributor wasn't advancing. Mechanic told me it wasn't getting enough Spark? So we replaced the whole distributor. New fuel pump. The carburetor has been completely rebuilt. I'm even running a new 12 gallon above deck fuel tank with fresh 93 octane fuel. Compression test was done and it checked OK? At least 147 lbs per cylinder. Timing & dwell were done bye a professional. Heres my TROUBLE. The boat starts and runs great in the driveway. The boat starts and runs good at the dock. I can raise the rpm's to about 4500. at the dock! Once under way runs so so. (While in no wake mode) But won't go over 2000 rpm's??? and shuts off then takes a moment to re start. There has been no such thing as WOT! The season is almost over and I'm almost out of my mind! Any And ALL HELP WILL BE MUCH APPRECIATED!

DHPMARINE · Aug 12, 2004

Re: Volvo expert needed

Re: Volvo expert needed

No expert here.But are you sure on the AQ131C 4 cylinder?I thought in 1990 they were using GM 3.0 Liter engines.If it is the GM motor I have an idea. DHP

FENIXX3435 · Aug 12, 2004

Re: Volvo expert needed

Re: Volvo expert needed

I'm no expert, but on the engine it clearly says "Volvo Penta AQ131C" All parts I have replaced on engine have been ordered for a Volvo Penta AQ131C, would much rather have GM engine. How I can I tell if its a GM engine? Are there markings to indicate this? Could Volvo say its theirs if its not?

DHPMARINE · Aug 12, 2004

Re: Volvo expert needed

Re: Volvo expert needed

No if it clearly says 131 it is a Volvo motor.I just didn't realize they still used them in 1990. My idea if it was a GM 3.0, h2o on top of the pistons,locking up the engine underload.I've had 4 of these this season,and everybody says there is no problem with this engine. So I replace the intake/exhaust manifold and no more problem. You could try pulling a couple sparkpugs when this happens,crank the engine over and see if water comes out of the plug holes.That would do it. The 131's also jump timing under load,but I wouldn't epect it on a 1990.Keep us posted. DHP

marinemech · Aug 13, 2004

Re: Volvo expert needed

Re: Volvo expert needed

check the area in the sterndrive where the exhaust gas exits i have see afew of the flaps get pushed in and the engine cannot breathe properly just a thought and good luck

Dunaruna · Aug 15, 2004

Re: Volvo expert needed

Re: Volvo expert needed

AQ131c was released in 1988, old stock on the showroom floor maybe? They did have a habit of jumping timing belt teeth due to lack of maintenance which can give similar symptoms to what you are describing. Aldo

FENIXX3435 · Aug 21, 2004

Re: Volvo expert needed

Re: Volvo expert needed

I pulled it apart, And the valve timing was off one tooth. Reset everything to specs. It fired up and ran better than it ever did! Only in driveway again? Took her to water, Ran so so about 3000 rpm's but real ruff. I'm convinced the timing is right. Unless it jumped again? But still have trouble. I think it's fuel related now? New tank, Fuel pump, carb was rebuilt? I'm not sure if it's clockwise or counter on my mixture screw? Seems to be dumping too much fuel? Carb is just one barrel small junk. Don't know it I should start over with new carb. Or is there something else I can check or try? When in driveway runs the best.But what good is it if you can't put her in the water?

placebo · Aug 21, 2004

Re: Volvo expert needed

Re: Volvo expert needed

Fen, I would check the timing again. Even though you are sure it is right! I have run Volvo auto's for years and have had to R&R timing belts more than once to get it right. One tooth can make a huge difference under load. I have also seen distributor trouble that will do the same, but I still suspect timing. Good Luck, David

FENIXX3435 · Aug 22, 2004

Re: Volvo expert needed

Re: Volvo expert needed

OK I took it apart again, And it has jumped timing again? Now what? How do I fix this? What makes it jump timing? The belt was new, The gears were cleaned. The washer and gear on the crank were even replaced. What else is there? What else can I replace or check. I know it was right when it was fired up the first time. But it has jumped again!

Dunaruna · Aug 22, 2004

Re: Volvo expert needed

Re: Volvo expert needed

Fenixx, I'm no volvo expert but I've changed enough timing belts in my time. A few things can cause a new belt to jump - wrong belt (different profile teeth or too long), worn pulleys (rust, pits, cracks), incorrectly tensioned (too tight is just as bad as not tight enough), worn tensioner pulley & spring, misaligned gears (bent camshaft, worn idler bearing etc). Even if pulleys looks o/k you need to check them closely for wear and 'feel' the idler pulley for roughness. Don't take any chances, replace any pulley that is suspect. The raw water pump can weep and cause rust build up on the pulleys also but that would become obvious when you remove the timing belt cover. Follow the workshop manual installation instructions closely, don't 'guess' the tension - this is a common mistake. Check your new belt for damage, jumping a tooth can cause cracking & tears. If it is all done properly you should get 500hrs between belt replacements without a problem. Aldo

FENIXX3435 · Aug 22, 2004

Re: Volvo expert needed

Re: Volvo expert needed

Aldo, I bought the boat, the water pump was replaced. Was told it needed a timing belt. I replaced crankshaft gear and big washer in front, washer had been worn to same size as the gear, even had gear teeth marks in it (matched up exactly). Distributor gear, camshaft gear, nothing wrong, just slightly corroded (cleaned up and painted). Idle tension pulley was replaced, third time I have replaced the belt and always replace with the one for Volvo AQ131C. I am not a mechanic, but I can read a book, and try to do what it says, you have given me more info than the book actually. For that I thank you. Is there anything else you think I could check other than the stuff I have already done? Or should I just junk it and replace the whole engine? I am strongly considering becoming a former boat owner. Mom says I was born to be on the water...maybe I should have joined the Navy, that has to be easier than this! Thanks, FENIXX

Dunaruna · Aug 22, 2004

Re: Volvo expert needed

Re: Volvo expert needed

Fenixx, I understand your frustration but don't throw the towel in just yet. Two things peak my curiosity, the worn washer and paint. For the large washer in front of the crankshaft gear to wear down it must have had metal to metal contact - either it was on backwards or something is misaligned, is their a corosponding wear mark? Paint will interfere with the meshing of the belt teeth and the pulley teeth. With the belt off, feel the idler pulley and the intermediate gear (distributor/oil pump shaft), both should feel smooth with no 'notchiness'. ANY uneven feeling will cause a harmonic vibration that can loosen the belt. Most timing belt problems begin over a period of time and culminate in a breakage or tooth skip. Using the maintenance history is often a good guide to discovering the cause. Over what period have you replaced three belts? Did the first belt replacement coincide with a pump replacement? The clues are there - we just need to find them. Aldo

FENIXX3435 · Aug 22, 2004

Re: Volvo expert needed

Re: Volvo expert needed

I bought the boat in April, From original owner. He told me the boat was running great @ WOT, When belt went. Then he parked it about 5-6 years. (Cause he had another boat) Said it need a timing belt/tune up. I could see that he had water pump replaced and new battery. {Did oil change, and complete tune up. Replacing plugs, wires, points, condenser, was told there was no spark, I replaced the coil as well. Put a new alternator on the boat, new fuel pump, new above deck fuel tank w/inline fuel filter (temporary until we get issues resolved). I put on a new timing belt. After turning over engine several times, I could see the belt was walking forward. So, we tore it all back down, inspected all gears, replaced idle tension pulley, and painted distributor gear and cam gear, replaced the belt (since the edge of the other had damage from walking forward). It was running, but running rough. Was told by professional mechanic, I was not getting spark and advancing. So I then replaced the complete distributor. At that time was told had carburetor issues, so had carburetor rebuilt. During this time I found IBOATS! Have received several ideas from others here. Tore it back down, replaced crankshaft gear, and noticed big washer between crankshaft gear and harmonic balance was worn down to same size as gear due to rust and corrosion. I am assuming that the replacement of the impeller, prior to me buying it, was due to part of this. Replaced the washer. I am not a mechanic, but I think the replacement has stopped the belt from walking forward. Set TDC replaced belt, aligned timing marks, put everything back together, and fired engine. Fired right away, ran better than it ever has. Shut it down went to water. Somewhere between initial start and the restart (25 Minutes) fired great, but had no power. After 2 hours of trying to make adjustments under load, it wasn't happening. Brought it home, tore it down, timing has jumped again. Belt is not damaged, but everything does not line up. I have since put a lot of money and time into something I have always wanted. I am learning a lot as I go along. It just that the season is almost over and I have yet to be relaxing on the water with the fishing pole doing the work. Looks like I have a nice long winter project. I do appreciate all help and advice.

Dunaruna · Aug 22, 2004

Re: Volvo expert needed

Re: Volvo expert needed

Excellent post, I wish more people would give that much information. Lets assume the previous owner parked the boat for six years because he was having exactly the same problem as you are now. One step at a time - put a straight edge (metal ruler?) against all the gears and look for anything that may cause the belt to 'walk'. Aldo

FENIXX3435 · Aug 23, 2004

Re: Volvo expert needed

Re: Volvo expert needed

I will try it this afternoon. But let's assume the gears are not warped? Where do I go from there?

Dunaruna · Aug 23, 2004

Re: Volvo expert needed

Re: Volvo expert needed

If everything is spinning 'true', no wobble, clean and properly matched cogs/teeth, idler and tensioner bearings running smooth - then it won't walk. The only other thing that can cause a belt to jump is a foriegn object getting under the teeth or the engine runs backwards momentarily at shutdown. Anyone else with ANY other ideas please jump in. Aldo

FENIXX3435 · Aug 24, 2004

Re: Volvo expert needed

Re: Volvo expert needed

I replaced The Crank gear, Both washers (front & Back of crank gear) The camshaft gear. ALL corresponding nuts & bolts. Cleaned the distributor gear. Removed all paint from it. Not sure how it will act. Didn't get enough time to finish. But it's first on list today. I feel good about it right now. The camshaft gear, was pitted in the center, just slightly. Couldn't get it smooth. So it was added to the list of new parts. How or why would the engine run backwards momentarily at shutdown? And how would I check for that? Thanks again for all your help.

FENIXX3435 · Aug 26, 2004

Re: Volvo expert needed

Re: Volvo expert needed

OK timing checks out fine. I'm stilling having trouble. Runs great! Just NOT under a load? Under a load I. Can't get more than 2500 rpm's without her bogging? The carburetor was rebuilt, New fuel pump, New tank with fresh fuel (93) its just a single barrel solex carburetor. I have good spark, Timing is advancing, Points are gaped to specs. We also have good compression. Any suggestions would be appreciated.

placebo · Aug 26, 2004

Re: Volvo expert needed

Re: Volvo expert needed

Fen, Sounds like your going in the right direction. What are you pushing for a prop. Too much pitch will prevent the engine from reaching WOT, even if things are right, though 2500 is low. I recently got 2 belts from a local supplier that had an extra tooth. They were both painted with the correct part #, but each had 1 tooth too many. Very frustrating. By the way, my cam washer was quite worn into the gear as well, but I used it anyway. Aldo is right on about the tensioner and the straigt-edge idea is great. If all three gear are not in the same plane, you are in trouble. Also, you state you had carb rebuilt. The Solex carb's are very simple, but have some area's that can collect quite a bit of sediment and dirt. Be sure to thoroughly clean all passages and screens. I have 3 on my boat, so if one is a little off it is not as big a deal. You only have the one, so it has to be perfect. Dave

fish393 · Aug 26, 2004

Re: Volvo expert needed

Re: Volvo expert needed

No expert but a shot in the dark.I had the same problem no power but ran fine.First I was able to get it to plane by pumping the throtle back and forth which would take the pressure off the crap in the carbs to let more gas through therefore it would plane.Second I was told to place my hand over the carbs one at a time which would make them choke themselfs and ask for more fuel there fore making it run and when I came to the bad carb it nearly throw me out of the boat.I know you only have one carb but it should do the same.You can a least try these and then alimanate the carb.You have done the hard work Look at simple stuff;Screens in the carb,gas tank ports,fuel filter and check for water in fuel separator.Do a pressure test on the fuel filter if you havent allready.Boats go through h473 when they sit for a while I bought mine and was told it only sat for a year and it took me a whole season before it seen water.Close it right this winter and advoid problems next year. hope this helps a little, good luck fish

Volvo expert needed

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