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I suspect you need to adjust your idle. Make a little wire connector for that diagnostic port on the driver's side rear (see https://www.lindseyracing.com/LR/Parts/IDLE944T.html) Warm up the engine on a ten minute drive then pop the hood and connect the "B" and "C" as indicated on the link. Listen carefully: if the idle speed changes much, I suggest you adjust it so that it is the same with and without the jumper.
Your idle adjustment screw may have moved--or it might be leaking. You can easily replace it with a new one (or just the O-ring).
FYI your vacuum looks solid (the boost gauge acts like a vacuum gauge below "1". You are showing a hair under the first line which on my dash is about 18 inHg--remarkable at cold start. I don't get that much vacuum until fully warm
I suspect you need to adjust your idle. Make a little wire connector for that diagnostic port on the driver's side rear (see https://www.lindseyracing.com/LR/Parts/IDLE944T.html) Warm up the engine on a ten minute drive then pop the hood and connect the "B" and "C" as indicated on the link. Listen carefully: if the idle speed changes much, I suggest you adjust it so that it is the same with and without the jumper.
Your idle adjustment screw may have moved--or it might be leaking. You can easily replace it with a new one (or just the O-ring).
FYI your vacuum looks solid (the boost gauge acts like a vacuum gauge below "1". You are showing a hair under the first line which on my dash is about 18 inHg--remarkable at cold start. I don't get that much vacuum until fully warm
Good feedback on the vaccum. I promise the vibration is more severe than the video would suggest I'm just glad it's only on a cold start. The car idles nicely and starts normally when up to temperature.
The car has a really interesting story per it's CarFax history. 6 months after arriving in CA in 1986 the car was stolen, recovered and sold at a police auction
Any idea what city where the car was stolen from? Circa 1986 I was working at a shop selling car phones, my customer parks his red 951 in front of the shop and comes in to have his phone installed. He's about 15 minutes early for his appointment. As we are chatting he sees his car pull away and mentions that we have fast service. I know right away that it's not our guys driving his car. I tell him I think his car is being stolen. I jump in my car, a Mercedes 190-16 valve and start following him. We are on a major street, El Camino Real. The thief has no clue he's being followed. He's driving normally, stopping at stoplights. I use my car phone to call the police to report what's happening. At the time, car phones were not too common. It took me awhile to make the dispatcher understand that I'm actually following the stolen car. Once she understands the situation she has me report my location. By this time the thief has turned off the main road into a residential area and has noticed me following him making all the same turns. He lights the turbo and takes off. While my 16 valve is no slouch, it's no match for the 951. As he pulls away from me, I see a black and white with its lights and sirens fly through an intersection about a half mile ahead. The thief see it too and makes a hard right going the opposite direction of the squad car. Then in my rear view I see another cop behind me. The dispatcher tells me they have us in sight and to pull over and stop following. I pull over to let the cops by but I really want to see what happens. I figure this is a situation where there is no way I'm going to get a ticket so I try to follow the cops at a pretty high rate of speed. Once the thief saw the flashing lights he said giddy-up and the "red hot" 951 obliged. I gradually lost sight of him and the chase and returned to the shop. My customer was sitting there in dis-belief. I relayed what happened and saw a glimmer of hope in his eyes. About a half hour later one of the officers stopped by to take the report and told us he got away. They broke off pursuit when he drove through a shopping center parking lot at 70 MPH plus. The car was recovered a couple of months later after my customer had already settled with his insurance company.
As I drove back to my shop, after the chase I knew I wanted a 951. Approximately 30 years later I got a red hot 951. AND it's parked next to my 190-16valve.
What's the chance your 951 is the very same one I saw stolen?
Any idea what city where the car was stolen from? Circa 1986 I was working at a shop selling car phones, my customer parks his red 951 in front of the shop and comes in to have his phone installed. He's about 15 minutes early for his appointment. As we are chatting he sees his car pull away and mentions that we have fast service. I know right away that it's not our guys driving his car. I tell him I think his car is being stolen. I jump in my car, a Mercedes 190-16 valve and start following him. We are on a major street, El Camino Real. The thief has no clue he's being followed. He's driving normally, stopping at stoplights. I use my car phone to call the police to report what's happening. At the time, car phones were not too common. It took me awhile to make the dispatcher understand that I'm actually following the stolen car. Once she understands the situation she has me report my location. By this time the thief has turned off the main road into a residential area and has noticed me following him making all the same turns. He lights the turbo and takes off. While my 16 valve is no slouch, it's no match for the 951. As he pulls away from me, I see a black and white with its lights and sirens fly through an intersection about a half mile ahead. The thief see it too and makes a hard right going the opposite direction of the squad car. Then in my rear view I see another cop behind me. The dispatcher tells me they have us in sight and to pull over and stop following. I pull over to let the cops by but I really want to see what happens. I figure this is a situation where there is no way I'm going to get a ticket so I try to follow the cops at a pretty high rate of speed. Once the thief saw the flashing lights he said giddy-up and the "red hot" 951 obliged. I gradually lost sight of him and the chase and returned to the shop. My customer was sitting there in dis-belief. I relayed what happened and saw a glimmer of hope in his eyes. About a half hour later one of the officers stopped by to take the report and told us he got away. They broke off pursuit when he drove through a shopping center parking lot at 70 MPH plus. The car was recovered a couple of months later after my customer had already settled with his insurance company.
As I drove back to my shop, after the chase I knew I wanted a 951. Approximately 30 years later I got a red hot 951. AND it's parked next to my 190-16valve.
What's the chance your 951 is the very same one I saw stolen?
Any idea what city where the car was stolen from? Circa 1986 I was working at a shop selling car phones, my customer parks his red 951 in front of the shop and comes in to have his phone installed. He's about 15 minutes early for his appointment. As we are chatting he sees his car pull away and mentions that we have fast service. I know right away that it's not our guys driving his car. I tell him I think his car is being stolen. I jump in my car, a Mercedes 190-16 valve and start following him. We are on a major street, El Camino Real. The thief has no clue he's being followed. He's driving normally, stopping at stoplights. I use my car phone to call the police to report what's happening. At the time, car phones were not too common. It took me awhile to make the dispatcher understand that I'm actually following the stolen car. Once she understands the situation she has me report my location. By this time the thief has turned off the main road into a residential area and has noticed me following him making all the same turns. He lights the turbo and takes off. While my 16 valve is no slouch, it's no match for the 951. As he pulls away from me, I see a black and white with its lights and sirens fly through an intersection about a half mile ahead. The thief see it too and makes a hard right going the opposite direction of the squad car. Then in my rear view I see another cop behind me. The dispatcher tells me they have us in sight and to pull over and stop following. I pull over to let the cops by but I really want to see what happens. I figure this is a situation where there is no way I'm going to get a ticket so I try to follow the cops at a pretty high rate of speed. Once the thief saw the flashing lights he said giddy-up and the "red hot" 951 obliged. I gradually lost sight of him and the chase and returned to the shop. My customer was sitting there in dis-belief. I relayed what happened and saw a glimmer of hope in his eyes. About a half hour later one of the officers stopped by to take the report and told us he got away. They broke off pursuit when he drove through a shopping center parking lot at 70 MPH plus. The car was recovered a couple of months later after my customer had already settled with his insurance company.
As I drove back to my shop, after the chase I knew I wanted a 951. Approximately 30 years later I got a red hot 951. AND it's parked next to my 190-16valve.
What's the chance your 951 is the very same one I saw stolen?
Wow. This is an incredible story. I was on the edge of my seat reading through. There's definitely a chance that my 951 could be the car you describe. I'm going to pull the CarFax again, I believe the police auction included the city it was sold from.
It's fun to imagine how flawless the performance of these cars must have been fresh from the factory.
Cars tend to have a bit more vibration when cold. From the video your car seems to sound good. Do you get a shudder or shake when you turn the car off? You can see the engine moving around a bit. Double check your invoice on the engine mounts. The part should be $500-$600 dollars without labor. There is another post here where the Porsche dealer was having a hard time installing the oe mounts. Turns out the mounts were not OE but OEM, ie Uro, mounts. The dealer and owner was unaware of this untill further research. People confuse OE and OEM all the time.
As a side note I would never bring a 944 to a Porsche dealer. They would be clueless in servicing a 944 compared to an indy Porsche shop. Most dealer techs probably have never seen a 944 much less worked on one. Not many people are going to the dealer for $200 oil changes. I say this as someone who used to work in dealerships (Porsche. Audi, mb, bmw and honda). 90% of the techs are R and R only techs (remove and replace- not capable of fixing)
To me . Its sounds like the t belts weren't tensioned properly. Which leads me to believe that the balance shaft belt wasn't indexed correctly either. I had this exact situation on my first 951. When a non professional shop did my belts.
I think everyone has covered most potential causes. I would recheck ports in the throttle body. Then of course recheck every vacuum hose. Especially that little two port hard to get one under the cycling valve. It’s temp sensitive. I typically find it’s the simplest thing and something I overlooked like tightening intake/ic/turbo boots etc. and your car is beautifully well kept. Great job
Thanks everyone for all the responses. I'm out of town until Tuesday but looking forward to double checking everything when I'm back. In Montana visiting my Dad and his friend has a 911 Turbo he said I could take out today. Should be fun.
Before I left I was able to pull the service for the motor mounts and it looks like genuine Porsche parts were used. I don't use this shop anymore as I've tried to tackle more projects on my own but this was the initial health check when first purchased the car.
Thanks for posting the garage charges... nice reminder how much I'm saving with DIY
Stolen car story is wild
Tell me about it! I paid around 8K for all the mechanical work including engine out, clutch etc. I dont necessarily regret it as I was new to the car and it was in rough shape but since that bill I've tried to DIY was much as possible. Expensive parts I can deal with but paying for time is the killer.
Expensive parts I can deal with but paying for time is the killer.
I'm the opposite: I can respect paying for someone's time... it's the parts markup that gets me. I understand the parts pay for the shop but 199 each for reference sensors is just nonsense given nearly identical are available at less than half that.
I do find the 400 alignment a little suspicious though
06-21-2019, 11:10 PM
I'm just glad it's only on a cold start. The car idles nicely and starts normally when up to temperature.
