99 vw loss of power...tried everything...please help

Which engine in this 99 Golf? Sounds like a 2.0, but am not sure even if this is a US model or what. I would ASSuME that since it is comcast that it is a US model. ;-)

How many fuel pumps does your 99 Golf have? 2? I would suspect a problem with the transfer pump in the fuel tank, if so equipped.

Possibly a ruptured Fuel Pressure Regulator that might allow gas to travel through vacuum hoses into the intake.

also did you ever get an Engine Check Light? Have you tried to hook up a ross-tech.com vag-com tool to the ECM to see what was happening?

Hi Dave,

I am so psyched that you wrote back. Yes it is the 2.0 and the car only has one fuel pump. My mechanic checked the fuel pressure and the fuel regulator twice and they both checked out alright. He also thought/stated that if the fuel pump was starting to fail, it wouldn't be able to put out the pressure. Wouldn't that take care of the ruptured fuel regulator?

Also I have gotten a check engine light...twice....not when it loses power and dies on the side of the road but twice when I let it idle for long periods of time with the AC on high and it stalled, which did not make my mechanic very happy! However, after all the times when I have let it idle like this is when it will then lose power a short time later. This is in addition to losing power on a number of others times when I am just driving "normal." In any case, both times when I got a code they were misfires, once in cylinder one, the other a random misfire. Today I have removed the gas cap thinking maybe there is some kind of clog, etc..in the Evaporative Emissions Control system. Seems to be a little better but it is hard to tell since the problem is so intermittent.

I have not tied to connect anything to the ECM yet. Can you tell me more about it? I will also check it out online.

Thanks a lot. I appreciate your help.

Andrea

Hi again Dave,

Is/isn't the computer my mechanic put on the car comparable to the the one you suggested? Yes?? No??

Andrea

andrea wrote:

Hi again Dave,

Is/isn't the computer my mechanic put on the car comparable to the the one you suggested? Yes?? No??

Andrea

andrea wrote:

Hmmm so he says that there is no fuel pump, or fuel delivery system, in the fuel tank? I am definitely not sure on this. Maybe that is the main fuel pump for your vehicle.

I have seen a lot of crud in fuel tanks that only clog the pickup strainer after running for awhile. Then of course when the engine stalls the vacuum that is created by the fuel pump drops to "0" and the crud falls back to the bottom of the tank. Then you can start the engine again and start this cycle all over again.

And like you said you removed the gas cap and it seemed better. Maybe there is a vacuum created inside of the gas tank that might cause a reduction in fuel pump pressure.

Fuel pumps need to create not only pressure but also volume. The ruptured fuel pressure regulator would probably only cause a very slight drop in fuel pressure. It is usally discovered when the vacuum lines to it are examined with the engine running. Of course some signs will be an engine that is idling rough, bad mileage, etc.

Hmmm since you said that your cap was replaced then I will assume that your '99 still has an ignition coil (transformer). That might be your problem and I only recommend purchasing them from the dealer. I have had problems with aftermarket brands.

good luck!

what is he using? some are only basically code readers and can read or erase DTCs (faults) and probably can't read info like a ross-tech.com tool.

Hi Dave,

He didn't say there wasn't one, he said that it checked out okay. According to my "research" there is just one fuel pump, the one in the tank. I had the gas cap off for two days but unfortunately that did not cure the problem, it came back repeatedly. The fuel tank was drained and there was no crud in it, it was clean. The coil was just recently replaced, and that did not cure the problem either. It has died 13 times in the last 6 days. Usually I can restart it after a minute or so, but the other day I had to wait 20 minutes until it was willing to restart. That's when I took the cap off but since then it's continued to die. I thought it all had something to do with the AC beng on high since that is when it struggles the most, except today I kept them completely off to "check out" if it would die. Unfortunately it did. I am very, very, very frustrated!! What about the possibility that is is a wiring harnes? Thanks for all your help.

Andrea

Or what about a starter relay???????

was that a vw dealer ignition coil (transformer) or aftermarket. That might be your problem if it was an aftermarket! I only recommend purchasing them from the dealer. I have had problems with aftermarket brands. Of course I only recommend BOSCH distributor rotors also. Both of those things above could give you problems that you are experiencing.

doubtful but it may be ignition switch causing it to die also

I've been kinda checking that out...but here's what happened today. Two times when the car died, in my effort to get it restarted...each time it took 3-5 attempts but once each time when I turned the key there was no cranking, completely dead...but the lights (oil, seatbelt, etc.) went on on the dashboard. If it was the ignition, everything I've read said those lights wouldn't go on. What about the ground to the intake manifold or an O ring in the fuel injector? I'll check tomorrow about the coil..but can't my mechanic tell if it's working appropriately?????? Here's something else...on Sunday it was hesitating every 10 feet, really struggling and then there was a loud bang coming from the engine compartment and suddenly absolutely zero hesitation, completely stopped. Later though I couldn't start it until after a couple of times...it would crank, start for a second (the accelorator would be to the floor) and then the tach would slowly decrease from 1000 to 0. Also one of the codes I got from Auto Zone was (I can't find the # right now) about the camshaft position sensor. I'm going to have the codes cleared tomorrow and then see if it comes back, etc. Any more thoughts? What about one of the wiring harnesses?

I've been kinda checking that out...but here's what happened today. Two times when the car died, in my effort to get it restarted...each time it took 3-5 attempts but once each time when I turned the key there was no cranking, completely dead...but the lights (oil, seatbelt, etc.) went on on the dashboard. If it was the ignition, everything I've read said those lights wouldn't go on. What about the ground to the intake manifold or an O ring in the fuel injector? I'll check tomorrow about the coil..but can't my mechanic tell if it's working appropriately?????? Here's something else...on Sunday it was hesitating every 10 feet, really struggling and then there was a loud bang coming from the engine compartment and suddenly absolutely zero hesitation, completely stopped. Later though I couldn't start it until after a couple of times...it would crank, start for a second (the accelorator would be to the floor) and then the tach would slowly decrease from 1000 to 0. Also one of the codes I got from Auto Zone was (I can't find the # right now) about the camshaft position sensor. I'm going to have the codes cleared tomorrow and then see if it comes back, etc. Any more thoughts? What about one of the wiring harnesses?

That pop sounds like a spark problem. Spark is affected by quite a few components, coil, cap, rotor, ESS, ECM, plug wires, etc. oh and even to some degree the ign switch. I will ASSuME that the battery and it's connections are clean and tight, esp. the grounds to the engine/trans and body.

I have seen new aftermarket ign coils have spark but the spark was so weak it would not fire the plugs well. Hopefully the ground strap to it is fine also. Have the codes checked before you have them erased. I have seen the Crankshaft Position Sensor (Engine Speed Sensor) not cause a code to pop up and also cause a '97 VR6 engine not to start.

Your mechanic should keep the vehicle so it can be tested while it is dying or dead! Give him the insurance card and a week to drive it. Whereabouts are you?

good luck!

Hi Dave, I am in CT. Where are you? You did assume correctly, battery connections are tight and clean. Today when they were checking it out, there were a number of codes, sometimes random misfires, sometimes cylinder 2 or 3 or 4...The ground to th intake manifold was cleaned. I'm going to assume he checked other ones but I will ask him later. I'll ask him about the coil too. (I forgot). Also...sometimes (only occassionally) when it dies and I'm trying to restart it, I will turn the key and it won't crank at all, completely dead like you have a dead battery but the dashboard lights eill still go on, then the next time I try it, it will crank and possibly start. The RPMs will rise to

1000 and then slowly decline back to zero despite having your foot on the gas pedal.

well if you get the EXACT CODES, post them here. If the battery is marginal that could cause some problems. It would be strange if you had a clogged exhaust causing your problems. Yes I know that you have a new cat, but I had a collasping rear muffler on my '91 Passat. Sounded OK at idle, but when you tried to accelerate too fast it clogged up. I also think you could have purchased a used car from what you have bought already for this one. But you will love it after the problem gets corrected! 8^)

Has the engine been put on an Ignition Scope?

I don't like that sometimes not cranking problem. :-( That is why I mentioned the ign. switch. I think VW has a recall on some Golfs' ign switches.

I am in Chicago and only guessing! ;-) later, dave (One out of many daves)

The misfire codes were PO300, 301, 302, 303, 304...in any case yesterday getting on the highway the car was beginning to die and then it backfired twice...brownish smoke out of the exhaust, died, then, got it started, died aboout 100 yds. later, backfired while trying to start it but this time under the middle of the car, and white smoke came billowing out on the side..sounds like it blew a hole in the exhaust...able to restart 5 more times for about 50-100 yds. each time and was able to finally get it off the highway. The past couple of days whenever it's died and you finally get it restarted there is always a huge smell of gasoline, kinda like it smells when and if you flood a car. My car then had to be towed to the mechanics.

The misfire codes were PO300, 301, 302, 303, 304...in any case yesterday getting on the highway the car was beginning to die and then it backfired twice...brownish smoke out of the exhaust, died, then, got it started, died aboout 100 yds. later, backfired while trying to start it but this time under the middle of the car, and white smoke came billowing out on the side..sounds like it blew a hole in the exhaust...able to restart 5 more times for about 50-100 yds. each time and was able to finally get it off the highway. The past couple of days whenever it's died and you finally get it restarted there is always a huge smell of gasoline, kinda like it smells when and if you flood a car. My car then had to be towed to the mechanics.

Also the battery is good. Yesterday when it was dying I kept finagling with the key and it would move the RPMs slightly, making them fluctuate slightly....if the ignition switch was bad, wouldn't the dashboard lights not go on when it stalled?

andrea wrote:

16684 P0300 Random/Multiple Cylinder Misfire Detected 16685 P0301 Cyl.1 Misfire Detected 16686 P0302 Cyl.2 Misfire Detected 16687 P0303 Cyl.3 Misfire Detected 16688 P0304 Cyl.4 Misfire Detected

Yeah that puzzles me since you have: excellent grounds to the engine, body and ign coil NEW cap, rotor, plugs, wires, coil, MAF, engine speed sensor(?) and other new components.

if the engine is running too lean, that might create some misfires. maybe your mechanic will catch the problem now that it is dying out more often.

hmmmm "brownish smoke out of the exhaust" don't forget to get that exhaust flow tested. maybe a clogged exhaust??

Yes generally if the ign switch is bad the idiot lights will not light up when the engine stalls, or the lights go out while cranking over the engine. Although on my '91 Passat when my ignition switch was going bad some components worked and other didn't. I could drive but not operate my power windows nor hear the radio. ODD huh? A new aftermarket ign. switch died in about a week's time. My rebuilt one at least lasted about 6 months, but the dealer's switch has been good for over a year so far.

guessing here again! good luck, dave (One out of many daves)