Hard to start after injector pump belt replacement

palmtree · #1 03-15-2012, 01:31 PM

I just had my IP belt replaced in a shop. The car runs fine but is a real pain to get started in the morning. Before the belt replacement the car always started almost instantly. Now it cranks for what seems like forever before it will finally start with some depression of the accelerator. I never had to touch the accelerator pedal to start it before the belt replacement. I am pretty new to this car and diesels in general. Is there some kind of adjustment he made when replacing the belt that makes it start different from before?
Thanks

Volvoist · #2 03-15-2012, 04:33 PM

I am guessing that the injection timing (hopefully not the cam timing) is off. That or the over tight belt has worn the injection pump input shaft bushing, and is now sucking air. It could be possible that you have a bad glow plug, but you'll need to check the timing first.
You can check for air by looking at the line between the fuel filter and injection pump (assuming you have or install clear tubing). If you see bubbles, you are sucking air, most likely from that shaft seal or bushing. Whatever you do, DO NOT, UNDER ANY CIRCUMSTANCES, USE STARTING FLUID (AKA ETHER) TO START THE ENGINE! Immediate damage can, and will, result.

v8volvo · #3 03-21-2012, 11:47 AM

How much smoke during cranking and after starting? More than before, or less? Rough running for the first couple minutes after a cold start? Minimal smoke during cranking before starting and fairly smooth running after startup is a likely sign of air ingress into the fuel system. Lots of smoke and poor running during and after starting points to incorrect (retarded) injection timing.

I second Mike's advice to absolutely avoid any kind of starting fluid. What kind of shop did the replacement? Do they have any VW diesel experience or tools? It sounds as though they have got the timing off as well as the belt too tight. Special timing tools (dial indicator and holder) are ***REQUIRED*** (not suggested, not highly recommended, but absolutely required) to set injection timing on any mechanical VW/Audi/Volvo diesel engine. Working without the proper tools, information, and techniques means you are shooting in the dark on timing, and are almost guaranteed to achieve an incorrect result that causes difficult starting, loss of power, reduced fuel mileage, excessive smoke, rough running, accelerated engine wear, and a litany of other problems.

It is a very easy task to do with the proper tools, which are available inexpensively on ebay. All the necessary info is available here. You could do the timing and belt tension adjustment yourself in a weekend afternoon, or a good diesel-familiar mechanic willing to learn a few new tricks (some are not!) and supplied with the appropriate information and tools could also do it without any trouble. Just to check the timing takes about 15 minutes with the dial tool; adjusting it takes a little longer but is quite straightforward once you understand what needs to be done.

If the fuel pump is leaking air in, that can be temporarily solved with a low-pressure electric helper pump in the fuel line. Even just installing a hand primer bulb in line before the fuel filter can help identify that issue; if putting one on and giving it several squeezes before attempting to start makes it start better, then you have an air leak. Proper fix is replacing the relevant pump seals, but my money is more on timing than fuel leakage. Generally with a leaky shaft seal, air leaks in when running but fuel leaks out when sitting overnight, so if that is your problem you should be able to see/smell evidence of fuel leakage from the rear of the engine. If everything is dry then you are focused on timing or perhaps glow plug issues... but unless you know for sure that your mechanic had the ability and equipment and inclination to set the timing right and did so, I would start there.

palmtree · #4 03-22-2012, 02:05 PM

Thanks for all the great help -- I really appreciate it.
Not much smoke, just a little white smoke when it would finally start. Maybe cranked over 15 times and would eventually start after I would depress the pedal to the floor. After it started it would run fine.
I started nosing around and noticed that the cold start device was disconnected. I re-engaged it and then it was starting about the same as before -- always started but not easy and took a while. I decided to change the fuel filter. I have driven the car about 3500 miles since I bought it and I have no idea when the previous owner changed it before. He did a complete tear down and rebuild about 8500 miles ago so I bet I was still running the original fuel filter. I decided I would change the oil and air filter as well. After all that was done it started right up instantly and is running great.
The guy that changed the IP belt (the second time) has worked on some VW's in the past and he does have the tools. This was his first Volvo but he said it was basically the same just on the back of the engine which makes it a literal pain in the back. He doesn't see many VW's either. I live in rural Missouri and he gets mostly pickup trucks and tractors. Anyway, he is pretty confident and has done it before on VW's. His shop actually rebuilds Bosch VE IP's too so he is very familiar with the pumps. Also the last belt that was too tight broke within 15 miles.
Sorry for the long post. Just wanted to say thanks for the help and I'm sure I'll need more help in the future since I'm new to these cars.
Brett

v8volvo · #5 03-27-2012, 09:22 PM

A clogged fuel filter will do it.

Glad you got it sorted out.

palmtree · #6 03-29-2012, 05:55 AM

Well, I thought I had it figured out.
After changing the fuel filter it started right up for a few days then it started getting harder and harder to start. This morning it started about like it did before the filter change (took a lot of cranking and wouldn't start until the accelerator was pressed to the floor). Then after about 45 minutes of driving I arrived at the office and it died as I was pulling into my parking spot. I had an appointment so I just left it for about an hour. When I went back out to look at it again, it would start, but slowly and not until I floored it -- just like first thing this morning.
My first thought is that there is a partial occlusion in the fuel line or maybe the tank pickup before it gets to the filter. That would explain, maybe, why it started up so quickly with a new and primed filter. Another possibility may be that something has already clogged that new filter.
Any other suggestions? I just hope I make it to the other office today (it's about a 30 mile drive). Wish me luck.

palmtree · #7 03-30-2012, 02:48 PM

I made it to my house yesterday. Had to coast into my parking spot because it died again (just got lucky twice in a row I guess). I changed the fuel filter yesterday on my lunch break. It started up pretty quick and ran fine yesterday afternoon/evening. This morning it started a little slow but not too bad. I took my daughter to school which is about a 15 min drive with some idling in the parking lot of the school without trouble. It ran just fine. Then I drove for about 35 minutes on the highway and as soon as I turned off the highway when the car was just coasting it died and would not start again. I walked the 1/4 mile to the office and worked for a few hours before borrowing someone's car to drive to O'Reilly to buy a fuel filter. I primed the new filter and put it on and started cranking, and cranking, and cranking. I drained the battery in my desperation to get it started and eventually gave up. Called my wife and a tow truck. Had my wife take me to the other office and the truck towed the Volvo to my house where it sits. Sorry for the long story.

My plan is to disconnect the hose before the filter and gravity feed diesel into the filter to see which side of the filter we are dealing with. I am hoping the problem is before the filter (in the tank or line). I'm not sure an IP rebuild is in the budget for this car -- it was just done 8500 miles ago according to the previous owner.
Any suggestions?
Thanks in advance
Brett

anders · #8 03-30-2012, 03:11 PM

Have you put a primer bulb in line between the car and filter? As V8volvo said, you can see if there is a small leak somewhere causing the IP to get air. Whats the shape of the rubber fuel lines and clamps? At one time on another diesel, I had a leaking banjo washer causing the IP to get air. If you have not all ready got the primer bulb I would get one.

palmtree · #9 03-30-2012, 03:18 PM

Quote:

Originally Posted by anders

Have you put a primer bulb in line between the car and filter? As V8volvo said, you can see if there is a small leak somewhere causing the IP to get air. Whats the shape of the rubber fuel lines and clamps? At one time on another diesel, I had a leaking banjo washer causing the IP to get air. If you have not all ready got the primer bulb I would get one.

Will do. Thanks for the quick response Anders.

v8volvo · #10 04-03-2012, 08:21 AM

First thing: don't keep driving it after it gets hard to start and loses power. It may not need an IP rebuild now, but it will soon if you keep asking the IP to suck against a blocked supply line. Transfer pump cavitates, pulls chunks of metal off and pumps through the rest of the system, and pretty soon you are in for major IP work. With any VE pump diesel, it is critical to shut the motor down at the first hint of fuel flow restriction or else the pump will self-destruct in short order.

Good idea to identify whether the restriction is before or after the filter. As Anders suggested, check condition of all hoses and clamps. One neat trick with a primer bulb is that you can actually use it as a rough vacuum gauge for fuel system work. If you install the primer bulb in line before the fuel filter and get the car running, the bulb should stay full and open. If the bulb sucks down flat as the car is running, then it means the pump is having to pull hard on the fuel line to draw from the tank. You can do the same test between the pump and the filter, but it is more difficult since that section uses a molded line with banjo fittings, and you also run the risk of introducing contaminants into the fuel system that way... so I would just do it before the filter. If the filter is restricted, the only thing to do is replace it anyway.

Quick "primer" (heh heh) about fuel filters.... if you have a car that is repeatedly plugging them, it is a good idea to try to see what is getting into them. Take the filter off carefully so as to spill as little fuel as possible, then dump it out into a clean container. What came out? Any obvious crud, dirt, water, rust? If so, then there is going to be more where it came from and you will have to either keep replacing filters until it is worked out, or drop the tank and clean the system out. If no obvious contamination, then it gets more tricky as to what is causing the problem. Air ingress or, as you suspected, an occluded tank supply line is the most likely issue at that point.

Also, what kind of filters are you using? If you are using a cheapo Fram, Wix, NAPA, etc, those are much smaller in capacity and will plug 10x faster than a proper OE style Bosch or Mahle Knecht filter. The Bosch filters only cost about $8 so they are worth getting a few of if you are in doubt. The other advantage of the nice filters from Bosch is that they have the smaller inner O-ring secured in place, whereas the cheaper ones do not. The difference there is that, if that O-ring is not held in place, it likes to not come off with the old filter when the filter is removed. Then, when your new filter is installed, there is a double O-ring around the threaded snout on the filter head, which can cause the new filter to not seat all the way on the head and allow air to leak in past the outer gasket. Or, worse, if you forget to install that inner O-ring because it is not fixed in place, you can end up having a filter on there that is allowing some fuel to bypass unfiltered... not good.

So, short version: especially if you are going through filters, consider getting your hands on some better fuel filters, and take care when replacing filters to make sure that there is no old inner O-ring still stuck on the filter head after the filter is removed, and the new filter's inner O-ring is in place during installation. Since Volvos have the filter mounted down low on the block, it is hard to see or feel if there is an old O-ring up there... get a mirror or feel up there carefully with sterilized clean hands, and pull any old ones off. I once worked on a car that had two ancient O-rings piled up there! Needless to say it was hard to get it to run well until I discovered that. This became such a problem for Volvo techs back when these cars were newer and on the roads in larger numbers, that Volvo actually issued a service bulletin in the late 1980s instructing techs to check for it.

If none of this gets you anywhere, report back... there are other, more weird causes for trouble like this... plugged screen in fuel return banjo, reversed inlet/outlet banjo bolts, etc... but starting with the basics is more likely to yield a solution. Just keep in mind that the entire fuel system is under suction, so any air leaks are tricky to trace because they won't leave big signs of fuel dumping out anywhere. An attentive eye and sometimes ear is required to find air leaks in VE pump diesels.