Idle Fine no run problem

bp042665

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#1
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MAKE:VW
MOD Cobrio
YEAR
:1999
MILES:
ENGINE:2.0
DESCRIBE ISSUE....Came In No Start Put Ignition Cap & Rotor Start's Fine But upon Test Dive It Falls On Face And Die's Starts Right Back Up But when Trying to accellorate it dies
 
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#2
any codes?
Then with scanner look at
Fuel Trims's maybe a failing pump.
Restriction in exhaust - MAP- holding @1500 a restriction will have reading drop. back toward baro (KOEO) reading.
 

nickb2

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#3
First, look for air duct crack, will open on accel, die. Then on start up, revs fine, but under load, no go. MAF readings out of whack and should have coded by now.

I realized it was a typo, and you meant cabrio. These 2.0ls were notorious for MAF problems. Also vac leak under the intake manifold. So look for that also.

Have someone throb engine in gear and listen to a whistling sound from the intake and air duct when under load. If parking brake sucks, just hit front of car to a good solid wall and stall test it. Check live data while doing so. If it dies under 30% or so calculated load, look to what I just wrote above.
 

nickb2

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#4
Another thing to look for as Kev2 mentioned, these down pipe volks, the cats like to disengage chunks of debris and cause a symptom as yours. The monolithe will move with back pressure back and forth. So removing the post cat o2 should releive some of that pressure and if the symptom still persists, go back and check what I wrote above.

Since I have time tonight, I did some internet search to confirm my own experience with these 2.0ls.

Here is a copy paste of a forum I fell upon. Knowing you just redid the secondary wiring, read the following so it will hit home for the next step of this trouble shoot.

I agree that this could be some form of secondary ignition failure but plug and wire replacememt usually resolves it. I have seen symptoms. You describe for other reasons also. Look at the maf sensor to throttle body accordian hose and make sure ther are no cracks developing between the segments. When this happens the cracks can open up when the engine twists on the mounts and causes hesitation. I have also seen a damaged catalytic converter cause similar symptoms when a chunck of broken monolith will jump in and out of the exhaust pipe and restrict it. If tje car has a converter you can take it loose from the down pipe to look inside for damage. With it disvonnected you can also tie it up with a coat hanger and test drive to see if there is any change in the symptom.
 

nickb2

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#5
More from same site. I tell you BP, this simple thing IS WAY OVERLOOKED

Check your motor mounts. I had a very similar experience with my 95 cabrio. Found out that all of the hardware and the front motor mount bracket was mangled. It would idle fine and rev in neutral without issue but once in gear and under load the car would lurch and jerk. The engine was trying to leave the bay. Look for a torn intake boot aswell.
 

nickb2

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#6
On these volks, the motor mount is called a hamburger cuz it looks like one, and those give out 90% of the time. They cause excessive movement under load and the dried up intake air duct can no longer flex so they just split from heat and the fact that volks used a very rigid and unforgiving ducting, also from the oil pressure sensor located just above the hamburger and lord knows a volks always leaks from the oil sending units.

The engine oil deteriorates the engine mount, and the rest just seems to be a repeat of itself. I have been working on these cars for the vast majority of my life, and the same thing always happens. Any good shop that does europe cars in North america has these parts in stock.

Volkswagon sucks for northern life, and you can be sure that you will never see one up here in the artic. We usually just let fire to them that is how useless they are.

No wonder the german army froze to death trying to invade russia. :D
 

nickb2

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#7
There is a huge difference from skiing in the alps and trying to get panzers across siberian lines.

Same applies here. Ok, now I am getting ahead of myself.
 

bp042665

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#8
thanks for all the input i have read live data and all the pips look great also have took off the pipe to cat and still die's im going to try and get back on this car today if posable raining here so dont know if i can but i will let you know if i get any clueson the vaccuum leak
 
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#9
- no codes, fuel pressure ok, no exhaust restriction, data good, FT,s, TPS, MAP - were good
A thought may fuel tank is not venting ?