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Golf85
Samba Member
Joined: July 18, 2014
Posts: 12
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 Posted: Fri Jul 18, 2014 5:37 pm Post subject: 1985 VW Golf Bucks Violently in 1st Gear |
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Hello All,
My 1985 VW Golf made a turn for the worse. It was running pretty good and then last week it started to buck violently starting out in first gear. I tried to adjust the idle/mixture and that made it worse.
It's a 1.8 gas engine with the basic CIS fuel injection system with a 5-speed manual trans. It is so bad, it is impossible to drive the car smoothly. I put it in 2nd gear once the car moves a few inches. Now it is starting to buck in second now and then. The car idles nicely and starts right up. Once I get it in 3rd gear, the car runs good and has plenty of power. Once I can get over 2,000 rpm's anyway. The car was tuned up about 17,000 miles ago with all Bosch parts (plugs, wires, dist cap, rotor). I had a spare set of plugs around, so I put them in. But nothing changed.
I hooked a multimeter to the Oxygen Sensor and it looks like the engine goes way lean between 1,000 and 2,000 rpm. There is very little power just off the 1,000 idle. (This is just my guess as the voltage goes way down off of idle).
I am trying to think of things that would effect the engine performance in that rpm bracket. Once I go about 2,000 rpm, the car runs great and has plenty of smooth power.
If the fuel pressure was low, I can see how it would effect power, but I would think it would also effect high speed. I guess I could buy another set of wires and dist cap and see what happens, but I am really just guessing.
Anybody have any thoughts on my problem. Should I take it out back and shoot it? That's what my Better Half wants me to do. |
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Golf85
Samba Member
Joined: July 18, 2014
Posts: 12
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| Posted: Fri Jul 18, 2014 5:43 pm Post subject: Here is my very sick puppy... |
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ps2375
Samba Member
Joined: April 24, 2014
Posts: 2471
Location: Meridian,ID
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| Posted: Fri Jul 18, 2014 8:12 pm Post subject: |
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| Any vacuum leaks? |
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Golf85
Samba Member
Joined: July 18, 2014
Posts: 12
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| Posted: Fri Jul 18, 2014 8:48 pm Post subject: |
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| ps2375 wrote: |
| Any vacuum leaks? |
I found a small one near the idle speed setting screw and fixed it. But it was pretty small, so fixing it didn't change anything. I did put a vacuum gauge and only got up to about 10 on my gauge. Seamed a bit low. But my gauge is pretty old and only goes down to 5 and not zero. |
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ps2375
Samba Member
Joined: April 24, 2014
Posts: 2471
Location: Meridian,ID
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| Posted: Fri Jul 18, 2014 11:11 pm Post subject: |
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| No tears in intake boot? Have you checked timing, ignition and mechanical? |
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Golf85
Samba Member
Joined: July 18, 2014
Posts: 12
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| Posted: Sat Jul 19, 2014 6:23 am Post subject: |
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| ps2375 wrote: |
| No tears in intake boot? Have you checked timing, ignition and mechanical? |
I will check the intake boot today... I forgot about that as it is big. Thanks.
I did check the timing and it is right on and steady. At least on cylinder 1.
Today (July 19), I think I am going to turn the mixture setting way rich and see if that makes any difference. Maybe I just have that all messed up. But it does idle very nicely and right at the 900 rpm mark.
I also noticed that there is the intake hose before the air cleaner that runs to the back of the motor (exhaust manifold) that is no longer attached to anything. So that is just sucking in air from the engine compartment. The ended of it rusted and broke off. But I don't think that really matters. Its about a 3" diameter hose and goes into the back bottom on the air cleaner. |
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ps2375
Samba Member
Joined: April 24, 2014
Posts: 2471
Location: Meridian,ID
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| Posted: Sat Jul 19, 2014 8:29 am Post subject: |
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| That is a preheat hose for cold weather, would not cause or contribute to any issue you are having now. |
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73sports
Samba Member
Joined: September 26, 2004
Posts: 2107
Location: Warrington, PA
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| Posted: Sat Jul 19, 2014 2:45 pm Post subject: |
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To me it sounds like one of the intake boots is cracked, either at the throttle body, or the fuel dist. When you pull away in 1st, the engine moves on it's mounts, and the split in the boot opens, creating a massive vac leak, and the engine almost dies, until the engine flops back forward and the crack in the boot seals up again, and everything starts to run again. Had an 86 jetta do that to me once.
_________________
I will never lie, but sometimes the truth changes.
Central Jersey VW Society |
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Golf85
Samba Member
Joined: July 18, 2014
Posts: 12
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| Posted: Mon Jul 21, 2014 3:12 pm Post subject: It's Alive!!! The problems has been resolved... |
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Thank you ps2374 and 73Sports for all your help.
It was a major vacuum leak. But before I found it, I turned the mixture adjustment as rich as it would go and the car ran much better. So I confirmed it was running lean. Of course being that rich, the car would not idle, but it did not stumble as much. Than I discovered the vacuum leak.
73Sports nailed it on the head. It was the intake boot at the throttle body. It was ripped underneath. It was just like 73Sports said:
"When you pull away in 1st, the engine moves on it's mounts, and the split in the boot opens, creating a massive vac leak, and the engine almost dies, until the engine flops back forward and the crack in the boot seals up again, and everything starts to run again."
ps2375 also mentioned the intake boot. You guys are good!!!
As a temporary fix, I just fixed the boot with some rubber cement, but I will buy a new one as soon as I can. But the rubber cement sealed the leak at least for now and the car is running great again.
Thank you ps2375 and 73Sports for helping me keep my old 1985 VW Golf on the road. |
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