Volvo Penta AQ131D will not start

[rdengil1]

I believe the engine is a 1989 AQ131D 4 cyl. I had the boat since last May, ran great through the winter until this past March. I took it out and when I throttled up, the water temp rose to 200-220. Immediately shut down and began to try and find the cause, no problem found, ran the boat at low speed water temp remained at 180. Returned to dock and when I got home, dismantled the exhaust manifold, the tube that runs off the heat exchanger was clogged with sediment and rust from the manifold. I cleaned everything out completely, and installed new gaskets, reattached the manifold after testing water flow, which was perfect on flushing. Started boat and ran, water temp fine and exhaust spewing water from the sterndrive as it should. OK, a week later, went to take it out, I usually warm it up at home first so it will start at the dock, (hard start in the cold), it started and stalled on 2 occasions then would not fire at all, I read numerous posts and followed several troubleshooting ideas with no result except $650 in the hole. Here is the testing I did. Checked cap, rotor, wires and plugs all good, spark everywhere, replaced condenser, coil, batter, rebuilt alternator (bad diode), changed plugs. still won't start, checked ignition switch per Don S. instructions posted in the forum, all good, tested the relay switch, checked good. Not sure what else to check its been over month and I can get it on occasion to run for a few minutes the cuts off and will not restart. Checked compression, 120 across all 4 cyl. checked fuel pump, turn the key fuel pumps to the filter, open the carb, fuel squirts from the jet when pushing throttle back and forth. Drained fuel tank and clean it out and refilled with fresh gas. I did notice the 40 amp circuit breaker, not sure if it is good or bad don't know how to test, the button will not push in and stay. What else can it be? When the engine is turning over, it sounds like there is no compression, but it checks fine? Maybe it sounds like that because it isn't firing? I'm at a loss. Thanks. Dennis

 

[captmello]

Re: Volvo Penta AQ131D will not start

Did you replace the timing belt?

 

[rdengil1]

Re: Volvo Penta AQ131D will not start

I replaced the timing belt back in January, I had taken the heat exhanger off to have it bead blasted and repainted and while it was off, I slipped the old belt off and put a new one on, boat ran fine for about 2 months after. Nothing moved on the cam or crank when changing out the belt.

 

[rdengil1]

Re: Volvo Penta AQ131D will not start

Is there a way for me to check the timing without the boat turning over? Also, could the Tachometer be bad, causing it not to fire?

 

[captmello]

Re: Volvo Penta AQ131D will not start

Yes. Static timing.

http://www.youtube.com/watch?v=hpp67aqwM2Y

Not sure on the Tach thing. You think the Tachs bad?

 

[Robj]

Re: Volvo Penta AQ131D will not start

I have seen a bad tach result in non-starting. You may want to try disconnecting it.

Have a great day,

Rob

 

[rdengil1]

Re: Volvo Penta AQ131D will not start

When I disconnect the tach is there something I need to do to the wires I take off the back of the tach? Thanks for the help all. I am about to sink this thing.

 

[rdengil1]

Re: Volvo Penta AQ131D will not start

Ok, so I ran through all the checks posted tested everything again, all good, except where I had 120psi compression across all 4 cylinders, today I have 0. Obviously it won't start without compression. So after replacing all the electronics and checking all the fuel, what are the compression issues, is there anything that would cause no compression, meaning electrical or is it all mechanical. How difficult is this job, is it a head gasket maybe leaking? or does it sound like valves and things in the cylinder, or if the timing is off, would that cause it. My point is what should I check before removing the cylinder head for repair. If removed what do I repair. Please take time to explain. Thanks. I really appreciate the help. Dennis

 

[Don S]

Re: Volvo Penta AQ131D will not start

it sounds like there is no compression, but it checks fine? Maybe it sounds like that because it isn't firing? I'm at a loss.

Have you checked for spark????????

 

[rdengil1]

Re: Volvo Penta AQ131D will not start

Don, without going back to the original post, here is the short of the problem. I took off the exhaust manifold and cleaned out the ports, replaced with new gaskets, boat started right up and ran on muffs for about 5 min. then went to go out again and it wouldn't start. replaced battery, had alternator rebuilt, new points, condenser, checked the ignition switch, tach, tested the relay, starter, changed plugs twice, ran through the fuel system all checks fine, checked compression 120 across all cylinders. Still won't fire, had replaced the timing belt while the boat was sitting without moving any gears back in Jan, this problem originated in March after taking the boat out a many times. Today, after following your test of the starting system, I decided to recheck the compression, 0 on all 4 cylinders, I had previously checked spark when I replaced the coil last week, sparks good at the coil wire, tested it on top of the rotor for insulation, no spark (as it shouldn't), then checked the plug end by removing plug and putting it to a ground, sparked. didn't check today though when I read 0 across the cylinders?

 

[rdengil1]

Re: Volvo Penta AQ131D will not start

check. I just checked for spark again since its dark out, nice blue spark. I know it is sparking at the plug at least. Tomorrow I will take out all 4 and test the compression again and post my findings. If it is no compression, what should I do? My point again would be to fix what I can without removing the head, if the head needs to come off, then I will do that as well, just want to avoid it if it isn't necessary yet. i.e. more testing to be sure. Thanks Dennis I also think the compression test was not done correctly? I removed one plug at a time, someone told me I need to remove all?

 

[captmello]

Re: Volvo Penta AQ131D will not start

Pulling all the plugs out allows the engine to spin freely with no compression.

No compression in all cylinders seems strange. you may want to test your gauge on the lawn mower or something that runs.

How hard is it to see the timing belt?

 

[Don S]

Re: Volvo Penta AQ131D will not start

I also think the compression test was not done correctly? I removed one plug at a time, someone told me I need to remove all?

Even if you remove one at a time, the compression will be more than zero.

I do see you are really in to throwing parts (and money) at it and hopeing for the best. By now you are probably figuring out you need to try something called troubleshooting so you know what to fix.

Exactly what service manual are you following for your testing and repair?

 

[rdengil1]

Re: Volvo Penta AQ131D will not start

Don, troubleshooting is what I have been doing. the parts that have been replaced either tested bad or needed to be replaced. SELOC is the manual used. when the boat wouldn't start, I started with checking the compression it was good, then on to the electrical, where I found my battery was dead, recharged wouldn't take, so replaced, then it died again, had the alternator tested it was bad so rebuilt, then while continuing to check the electrical system, my points were shot (had build up) so replaced those and the condensor. At this point is still won't start, so I replaced the coil and stopped there, the ignition switch and relay tested fine, on to the fuel system no clogs, a little water visible, so drained the tank and dried then refilled with fresh gas, changed plugs, checked the carb, gas going to fuel filter from pump and out the carb. The motor just sounds soft and will not fire, there is spark at the plug as I pulled it out and checked. put some gas down the intake and still won't fire. I don't think I have thrown any money at the problem, only replaced failed or failing parts that would eventually cause an issue, however I also know that none of them fixed my problem as the boat still won't start. It turns over fine just no fire, I am going to recheck the compression as I found out it is almost impossible to have zero on all 4. while doing this, I will recheck the timing belt to see if it is moving as well, (it was replaced in January while doing routine maint. nothing on the boat was moved. meaning the old belt slipped off and the cam and crank weren't moved at all, the new belt slipped back on. boat fired up and ran well until march when i found the clog in the pipe leading to the exhaust, which is when I took it off and cleaned out the debris and reattached the exhaust manifold with new gaskets. Thanks Dennis

 

[Don S]

Re: Volvo Penta AQ131D will not start

How sure are you that you have the timing belt on correctly? Were the marks on the belt inline with the marks on the wheels and cranksharft?
It sounds to me like you have the belt on wrong and the valves are opening when they should be closing.
Do you have the OEM service manual to go buy?
If not, download it here.

http://www.4shared.com/file/64741910/25295432/230_250_251_131151171.html

 

[rdengil1]

Re: Volvo Penta AQ131D will not start

Don, now that you say that about the timing belt let me ask this. when the boat ran, I shut it off and parked it, the next day removed the belt by just prying it off no movement of any parts. The new belt I just put on the same way, again no movement. everything was where it originally was when I turned the engine off. I was told I didn't need to line up anything since I did not disturb anything and only changed the belt. Is this not correct? Is there a specific mark on the belt that needs to line up with the other gears? I know that after I did this, the boat was running as if I never changed the belt, ran for about two months with no issues. The only issue started after I removed the exhaust. I rechecked the compression today, zero, put my finger over the plug hole and hand cranked the engine, got suction, just no blow out. This was the same on all cylinders. Is there something I am overlooking? I will download the manual next. Thanks. Dennis

 

[Don S]

Re: Volvo Penta AQ131D will not start

The timing belt is wrong, why or how, I don't know. But you might as well download the manual, pull the belt and reinstall it and see if that brings your compression back.

 

[rdengil1]

Re: Volvo Penta AQ131D will not start

Will give it a shot. I'll try it tomorrow and post the result. Just not sure how the boat will run fine for months then just not work. Luck?

 

[Don S]

Re: Volvo Penta AQ131D will not start

Just not sure how the boat will run fine for months then just not work.

EVERYTHING works great, right up to the time it breaks......... EVERYTHING.

 

[JustJason]

Re: Volvo Penta AQ131D will not start

on every belt or tchain I have ever done you almost always have to hold the cam gear with a wrench where ya want it. They never not shift 1 way or another when you take the belt off. All it takes is a few degrees, or 1 or 2 teeth to screw you all up.