Miserable season

[Campbell]

I haven't had a season like this in many, many years. I tried another race this weekend with nothing but problems. The car did run lean the first day (my 84 Scirocco) and I finally did determine the CPR was not stable (suggested strongly in another thread) - once changed the fuel mixture was solid however I could not pull any rpms. Last season I could easily pull 6500 but this weekend I could not get to 6000 and it got worse as the weekend went on - top rpms dropped to 5800 then 5500. I had fuel, it was not cutting out at all, although it would flutter under 4500 when floored (I did swap ignition distributors, still no power) and I checked my compression: 165 to 170 across all cylinders. I simply had no pull.

I was blowing oil from somewhere, it was wet on the fuel distributor and behind the engine on the transaxle and axle shafts.. someone following me said they saw a puff of blue smoke out the tailpipe when I let off the gas, not when I was on it.

What do you check when you can't get top end power? is it possible to have an engine blowing oil out the head gasket but not lose compression? I guess I will pull the tranny to make sure the rear main is okay although the engine was completely rebuilt at the start of last season (this is its second season) and I am not sure anything was coming out the timing hole... chances are oil was going in I think.

I am very frustrated and would be interested in ideas you may have. thanks

[racer_tim]

I'd check the ignition timing and the timing belt, to make sure that your not 1 tooth off somewhere.

Would the engine rev to 6k without a load? If so, I'd check the wires and electrical stuff.

What did the plugs look like? If you had blowby in the fuel distributor and the rear of the engine, there must be oil coming from somewhere.

How many breather's do you have? I have one on the valve cover, and 1 on the mech fuel pump cover. I have heard that you need both on the 8v VW motor.

What procedure did you use to break in the rings?

[lateapex911]

someone following me said they saw a puff of blue smoke out the tailpipe when I let off the gas, not when I was on it.

[/b]

Thats a classic valve guide situation. I would check leak down.

[zracre]

your control pressure could still be off...you could be too rich now. I am no expert with K-Jetronic but I know my car ran great once we figured out the warm up regulator (cpr)

[Campbell]

I'd check the ignition timing and the timing belt, to make sure that your not 1 tooth off somewhere.

Would the engine rev to 6k without a load? If so, I'd check the wires and electrical stuff.

What did the plugs look like? If you had blowby in the fuel distributor and the rear of the engine, there must be oil coming from somewhere.

How many breather's do you have? I have one on the valve cover, and 1 on the mech fuel pump cover. I have heard that you need both on the 8v VW motor.

What procedure did you use to break in the rings?
[/b]

It went to 4500 without a problem when I set the timing, I will go to 6000 and see what happens. Before I changed the CPR the plugs were honey colored to dark brown and the metal piece was rusty red. I haven't checked them after the CPR change.. I could have gone too rich - would that cause me to lose power?

I just have one breather on the valve cover. I looked closer at the engine last night though not for long, I had enough for one weekend. The oil had sprayed on to the radiator shield, both the front and passenger side of the fuel distributor (but not the back), and over the shift linkage and differential. It would have been a perfect oil pressure sending unit leak/spray but it was dry however the head gasket area on the drivers side and back was wet with oil. Maybe revving to 6000 rpms will show me something.

The valve guide leak down makes sense on the puffs of smoke. Right now my plan is to go back through everything as thoroughly as I can - including pulling the head and getting it freshend.

thanks

[zracre]

how were the coolant and oil temps? and yes I found my rabbit to lose power on top when it was too rich

[Campbell]

It did run hot all weekend, although it did improve a little bit with the changed CPR. I don't have a water temp gauge just the oe one - the needle was towards the top. This with the bigger Golf rad installed.

[zracre]

As racer_tim mentioned I would definitely check the cam tming (easy) reset the ign timing and check the Control pressure. These cars can be a pita when everything isnt set right but when they are good you shouldnt have problems with it...mine was too easy on me good luck! I dont know many people up there, but Gary Tyssen used to run a sirrocco up there with good results...i dont know if he still is, but i believe his son is (he used to run a corrado)

[Campbell]

Thanks, I will check the timing belt, actual timing and fuel pressures again. I also will do the 6000 rpm run and hopefully will see where the oil is coming from. The car has run well before and when it had issues they were easy to identify and fix.. not this year.

[Joe Craven]

I and one other VW GTI MK1 racer has experienced what you describe and in both of our situations, replacing the ignition coil fixed the high rpm problem.

Have you checked your coil?

[msogren]

Keep the timing at 32-33 BTDC for a session and check it out.. I guess that you have 36 or more lead and have blown the head gasket on the # 3 cyl, very slightly. Also , balance the injectors. If it ran OK last year and the cam is still right, that may be Ok but is worth a look at. Usually the newer guys run too much ting for the long pulls that a race car gets.
Pull the fuel filter and use Bosch only there.
Any chance that your car is red??
IMHO. MM

[Campbell]

I will try in the next couple evenings to check the coil and do the 6000 rpm run and let you know how it goes. The timing is always set at 33 btdc @ 4500 rpm - I checked the injectors when I had the lean issue before and they looked good. I hope it is a head gasket, that would explain a lot - hopefully the 6000 rpm will show me something. thanks for all your suggestions. Like most racers the discouragement only lasts a day and now I am very motivated to get it right for the next race!! my wife has no comprehension why I do this!!

[racer_tim]

At least your wive knows where you are. I'm either in the garage working on the race car, or in the office, working on one of many computers.

[keycom]

Howsa bout an update!

Best wishes.

[Campbell]

I haven't gotten that far, when I went to do the 6000 rpm run I remembered that I blew a radiator hose which ended my weekend (it was such a wonderful weekend I forgot all about that since it was the least of my issues!!) - more on that. I climbed around the car and seem to have both tranny fluid and oil spraying all around. So I know I have to pull the tranny (must be bad seals) and I assume the head (if the valve seal is leaking wouldn't that hurt top rpm compression?). I also have on my list to check the coil as well. I do want to do the 6000 rpm before I take it all apart.

I guess I could just replace the hose and fill it with water to start it up.. but I have been thinking I should re-pipe things. The hose that broke was the forked hose that goes from the water pump to the oil cooler and up to the expansion tank and the side of the head. I am thinking I should just pipe straight to the expansion tank and bypass the oil cooling (just have the filter on the flange) and cap off the inlet on the side of the head. This way the only coolant going in the motor will be from the radiator. Right now the hot oil coolant and the hot expansion tank bypass go straight back into the motor.. any thoughts on this? thanks

[Campbell]

My bad luck continues.. I fired it up tonight - ran it at 6000rpm to 6200rpm both in and out of gear for a while and everything worked great. Control pressure was 50 psi, system pressure 68 psi. Frequency valve worked fine, it wasn't running lean. Timing at 4500rpm was 33, creeped to 35 at 6000rpm. There was no missing, no fluid leaks (a lot of burn off of the previous fluid coating from the track). It ran great. Temp control was fine.

I am at a loss on how to trouble shoot this other than heading back to the track and see what I can figure out under load. That is a frustrating way to do things.

[shwah]

My bad luck continues.. I fired it up tonight - ran it at 6000rpm to 6200rpm both in and out of gear for a while and everything worked great. Control pressure was 50 psi, system pressure 68 psi. Frequency valve worked fine, it wasn't running lean. Timing at 4500rpm was 33, creeped to 35 at 6000rpm. There was no missing, no fluid leaks (a lot of burn off of the previous fluid coating from the track). It ran great. Temp control was fine.

I am at a loss on how to trouble shoot this other than heading back to the track and see what I can figure out under load. That is a frustrating way to do things.
[/b]

I just run fixed timing, that way I can set it at idle and know what it is at 6000. It should be fully advanced in race conditions anyhow IMO.

You could head to a dyno and run it under load with a wideband O2 sensor. Then you will know for sure if it is fuel, and can tune it properly right then and there. When I did my first event with my car it ran soo bad it was unbearable. I got through the weekend, but had to shift at 4500-5000 the whole time. Went to a dyno, found that it was running at 17:1 AFR, tuned it properly and picked up 25 hp.

If you decide to do this, GRD (Genesis Racing Development) on Ogden in Naperville has a decent Dynapac dyno system that is a true load dyno, rather than an inertia dyno (Dynajet, Mustang). This means you can hold the car at a given rpm under full throttle measuring power and making adjustments.

Good luck Bill. I look forward to seeing you with a big smile and a reliable running car at the track.

[Campbell]

Thanks Chris, I will give them a call.

I have gone through the car several times and boy it runs great in the garage. I am going to try running Saturday at the Autobahn regional and see if I can figure anything out while it is under load. Hate to do that at a race but my options are slim for track time. Next will be the dyno (I am going to swap the head out first). thanks

[Campbell]

I did call the GRD dyno place to see about an appointment and they wouldn't do any "tuning" on my car - only base runs. They thought I would be wasting my time. Apparently they only "tune" late model cars and were not interested in my A1 VW.

Back to basic troubleshooting at the track!!

[JamesB]

Cuz you called a tuning shop that only knows how to plug in parts. Talk to some of the racers and find out from them where you can look. thats what I did, and found 3 dynos that have very nice hourly rates to let me mess with timing and fuel mixture to get the optimal power without the chance of blowing up the motor.