| non-GMC- VW cabrio (Jetta) - diagnosis help [message #74012] |
Tue, 16 February 2010 06:34  |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
|
Senior Member |
|
|
The VW forum has lots of knowledge but I'm hoping someone here can provide wisdom, theory and insight. I know there's a few VW Toads (besides Dan's beetle)
Car has no power- how do i tell the difference between a fuel flow problem and a timing problem?
Background:
97 Cabrio has the same 2L ABA non-turbo engine as Jetta's from that period.
I bought this car cheap with a blown head gasket due to a catastrophic coolant leak.
I replaced the gasket and fixed the leak without doing anything else to the head. My thinking was i wanted to see the car run before deciding to invest any more in it.
It runs, it stays cool, the head does not leak, but it has no power. That's the mystery.
I spent a lot of time on valve timing- I am pretty sure i interpreted the little marks correctly.
It starts easy, idles smooth at 1000 RPMs. and seems fairly normal on takeoff but it bogs down when i step on it and struggles to get up to 60 in 5th gear.
I've owned a lot of crappy cars. This feels different- it's feels right in between bad timing and bad fuel flow.
Of course, my troubleshooting leads me first to things i messed with during reassembly. I believe the seller, that the car ran fine until the catastrophic event so I'm not really looking for a new problem. I don't expect a bad fuel filter or weak fuel pump. But anything is possible.
I don't think it's damage to the valves because it seems to have bursts of power at certain RPMs
thanks
emails or PMs welcome - dave@davesilva.com
Dave
|
|
|
|
| Re: [GMCnet] non-GMC- VW cabrio (Jetta) - diagnosis help [message #74021 is a reply to message #74012] |
Tue, 16 February 2010 07:49  |
Kingsley Coach
Messages: 2691
Registered: March 2009
Location: Nova Scotia Canada
Karma: -34
|
Senior Member |
|
|
Dave
Assuming it did run ok before the problem , the last guy to mess with it was
.....you <g>
Therefore, it's a timing problem.
Go back and check everything and when you finish, make sure the vacuum
lines to the dist are not messed up.
I must admit I couldn't figure out a problem with a 95 diesel one
time....yep, filter.
So with that in mind, change the fuel filter and then go back to the
timing.....
Maybe I just don't know and maybe I should have never started typing. <vbg>
Mike in NS
On Tue, Feb 16, 2010 at 8:34 AM, dave silva <gmc@davesilva.com> wrote:
>
>
> The VW forum has lots of knowledge but I'm hoping someone here can provide
> wisdom, theory and insight. I know there's a few VW Toads (besides Dan's
> beetle)
>
> Car has no power- how do i tell the difference between a fuel flow problem
> and a timing problem?
>
> Background:
>
> 97 Cabrio has the same 2L ABA non-turbo engine as Jetta's from that period.
>
> I bought this car cheap with a blown head gasket due to a catastrophic
> coolant leak.
>
> I replaced the gasket and fixed the leak without doing anything else to the
> head. My thinking was i wanted to see the car run before deciding to invest
> any more in it.
>
> It runs, it stays cool, the head does not leak, but it has no power.
> That's the mystery.
>
> I spent a lot of time on valve timing- I am pretty sure i interpreted the
> little marks correctly.
>
> It starts easy, idles smooth at 1000 RPMs. and seems fairly normal on
> takeoff but it bogs down when i step on it and struggles to get up to 60 in
> 5th gear.
>
> I've owned a lot of crappy cars. This feels different- it's feels right in
> between bad timing and bad fuel flow.
>
> Of course, my troubleshooting leads me first to things i messed with during
> reassembly. I believe the seller, that the car ran fine until the
> catastrophic event so I'm not really looking for a new problem. I don't
> expect a bad fuel filter or weak fuel pump. But anything is possible.
>
> I don't think it's damage to the valves because it seems to have bursts of
> power at certain RPMs
>
> thanks
>
> emails or PMs welcome - mailto:dave@davesilva.com
>
> Dave
>
>
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Michael Beaton
1977 Kingsley 26-11
1977 Eleganza II 26-3
Antigonish, NS
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: non-GMC- VW cabrio (Jetta) - diagnosis help [message #74025 is a reply to message #74012] |
Tue, 16 February 2010 08:14 |
Luvn737s
Messages: 1106
Registered: June 2007
Karma: 2
|
Senior Member |
|
|
Check Catalytic Converter. That could have caused the head gasket to blow before. I parted with my first good car (Mazda 626) when I was young for pennies because I never checked that. Only years later when the same thing happened to a GEO Prizm did I find that a blocked Cat can do that.
Man, cars seemed to have so much more seatbelt back then... 
Randy
1973 26' Painted Desert
Ahwatukee (Phoenix) AZ
[Updated on: Tue, 16 February 2010 08:14] Report message to a moderator |
|
|
|
| Re: non-GMC- VW cabrio (Jetta) - diagnosis help [message #74032 is a reply to message #74012] |
Tue, 16 February 2010 09:25 |
idrob
Messages: 645
Registered: January 2005
Location: Central Idaho
Karma: 0
|
Senior Member |
|
|
I agree with Randy, could be the cat converter. I had one break on a Quantum and had no power at all.
Also, did you check the valve timing? I believe that the VW's use the same rubber belt on the overhead cam that the Audi's have, and if it got put on wrong, the valve timing could be off causing the issue.
Rob Allen
former owner of '76 x-PB
|
|
|
|
| Re: non-GMC- VW cabrio (Jetta) - diagnosis help [message #74039 is a reply to message #74012] |
Tue, 16 February 2010 11:33 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
|
Senior Member |
|
|
I like the 'potatoe in the exhaust' theory. (Blocked cat). Runs good on low demand and no power on more demand is the classic symptom. If a helper floors the car while you listen at the tail pipe a nonlinear output with pressure build up and delay in the 'decay time' when foot is removed is the blockage symptom. Of course I'm a sound guy and diagnose most things 'by ear'.
John Lebetski
Woodstock, IL
77 Eleganza II
|
|
|
|
|
|
| Re: non-GMC- VW cabrio (Jetta) - diagnosis help [message #74076 is a reply to message #74012] |
Tue, 16 February 2010 18:37 |
 |
mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
|
Senior Member |
|
|
| hertfordnc wrote on Tue, 16 February 2010 04:34 |
The VW forum has lots of knowledge but I'm hoping someone here can provide wisdom, theory and insight. I know there's a few VW Toads (besides Dan's beetle)
Car has no power- how do i tell the difference between a fuel flow problem and a timing problem?
Background:
97 Cabrio has the same 2L ABA non-turbo engine as Jetta's from that period. ...
|
Dave,
I think your VW is new enough to have a OBD connector. That means you can use VAG Com software, an interface and a laptop to read the computer codes. That would be where I would start.
<http://www.ross-tech.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=VAGCOM>
<http://www.ross-tech.com/vag-com/cars/applications/beetlecabrio.html>
I have a USB Hex-CAN and an older serial (RS232) cable interface that only works with the old shareware software. Either should work on your car, and I would lend it to you if you where closer. A bit of searching on the internet should give you information on the software and interfaces.
I use mine on our 2000 Audi A6 2.7t. It is worth the money if you plan on keeping cars that use the VAG equipment. They say it will also read generic OBDII codes.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
|
|
|
|
|
|
| Re: non-GMC- VW cabrio (Jetta) - diagnosis help [message #74091 is a reply to message #74083] |
Tue, 16 February 2010 20:36 |
klassic kampers
Messages: 93
Registered: July 2008
Location: greer,s.c./ellijay,ga
Karma: 0
|
Member |
|
|
been doing vw since 1972..........sounds like the cam is retarded...to double check your ability to align timing marks, remove the valve cover and with the #1 piston up, align the marks and be sure that the #1 valves are closed with the lobes forming a "V"........if the "V" is tilted either way then your cam timing is not correct.......if the intermediate shaft is not aligned correctly then your ignition timing is off(probably retarded).....
if the engine digested an anti-freeze/oil mixture then the cat could be very well clogged......the easiest way to check is with a scanner, but the simplest is to pop off the exhaust above the cat and drive..........this car should easily do 60mph in 3rd gear.........
does not sound like a fuel flow problem unless the car had been sitting for a long time before you acquired it and the infamous ethanol is losening up the dead gasoline varnish and restricting fuel flow..........vw/audi vehicles really like clean fuel filters as the 77-80 rabbits would roast the fuse panel if the fuel filter became restricted........
good luck.........
Mike Stewart
1973 GMC 26' Canyonlands /
1973 B.S.A. B50 street tracker-----
Greer,S.C/Ellijay,Ga
|
|
|
|
| Re: non-GMC- VW cabrio (Jetta) - SOLVED - THANKS [message #76720 is a reply to message #74091] |
Mon, 15 March 2010 11:52 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
|
Senior Member |
|
|
Just thouht i'd share the results. It was a while before I had a weather window to get back to this problem.
I finally got around to dropping the cat and busting it in to a straight pipe.
Worked like magic. I'm driving the car. It's getting 28MPG.
The lesson learned from all this is the difference between KNOWLEDGE and WISDOM (or insight)
The folks on the VW board, who possess vast, detailed knowledge of these cars, could not, from the information I provided, offer a unifying theory on why I could not get it to run right.
-- FOLLOW UP QUESTION-
I put the head back on with no book, i got torque values online and faked it. How many miles do I need behind me before I can be reasonably confident I got it right? Will a head gasket fail right away if it's wrong, or could it crap out after 10,000 miles.
thanks
Dave
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
|
|
|
|
| Re: non-GMC- VW cabrio (Jetta) - SOLVED - THANKS [message #76754 is a reply to message #76720] |
Mon, 15 March 2010 16:08 |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
| hertfordnc wrote on Mon, 15 March 2010 12:52 |
<Snipped> Good for you
-- FOLLOW UP QUESTION-
I put the head back on with no book, I got torque values online and faked it. How many miles do I need behind me before I can be reasonably confident I got it right? Will a head gasket fail right away if it's wrong, or could it crap out after 10,000 miles.
thanks
Dave
|
Dave,
If it makes it to 500, you are probably good. The big killer of cylinder head gaskets is thermal cycles. After about 10 full thermal cycles, if there isn't coolant either peeing on the ground or what is in the radiator is not like a milkshake, you scored.
You do not say what you did do - just that you faked it.
VW has been "torque and turn" to pull fasteners to yield for two decades.
Did you use new fasteners?
Did you preset at some nominal and then do two passes of 90* or some such thing?
Matt (used to run the aftermarket at McCord Gasket)
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
| Re: non-GMC- VW cabrio (Jetta) - SOLVED - THANKS [message #76776 is a reply to message #76754] |
Mon, 15 March 2010 20:13 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
|
Senior Member |
|
|
I didn't change the bolts. I did find a source that indicated it's not absolutely necessary on that particular engine..
I did get a baseline torque and then hit it two more times at 90 degrees. But it was dark and cold and rushed (borrowed torque wrench)
I had no book. Just kept attaching things until there were very few spare parts left.
I was pretty amazed when it fired up.
I've driven it about 700 miles including a long hard run at a constant 75-80 -- runs great.
Thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
|
|
|
|
| Re: non-GMC- VW cabrio (Jetta) - diagnosis help [message #76817 is a reply to message #74012] |
Tue, 16 March 2010 09:49 |
WayneB
Messages: 233
Registered: July 2008
Location: Ontario, Canada
Karma: 0
|
Senior Member |
|
|
Did you check the head and block surface are flat and true before you put it back together?
Aluminium cylinder heads are not as forgiving as their cast iron brethren, they need to be absolutely dead flat, and gradually torqued down in the correct sequence.
I always check aluminium head surfaces for flatness and alot of the time I will have them skimmed If they are a little corroded to make 100% sure.
Very rare that an aluminium head will not need skimming after blowing a head gasket and /or overheating.
1976 23' GMCII By Explorer
|
|
|
|
| Re: non-GMC- VW cabrio (Jetta) - diagnosis help [message #76833 is a reply to message #76817] |
Tue, 16 March 2010 12:42 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
|
Senior Member |
|
|
Well yes, that is the question. How good is that head?
I committed many crimes against good mechanincs here.
I bought this car to canabalize for my wifes Cabrio. But it was in such nice shape I thought, why not bolt it back together and see how it runs? I limited my budget to the head gasket and an oil change. I felt to spend any more on a totally untested car would be foolish. As it happens, it has no reverse, the brakes are just OK, the steering pulls a bit, there is evidence of at least a minor wreck, and the right windo motor is bad and they cost $300.
I checked the head as best I could with a peice of glass. It seemed pretty straight.
So, i guess if i get a few thousand miles out if it I'm home fre. And maybe I'll fix the other things.
thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
