3.0 problems

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mac74
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3.0 problems

Post by mac74 » Mon Apr 24, 2006 2:38 pm

Hi!
I've just installed a 3.0 engine coming from a 75/Milano in my GTV6. Tonight was the night for the first testdrive. Just had to install the exhaust manifolds and were then set to go.....I thought!

It seems like the engine only fires on the left bank. I've got spark on the right side but no action. It runs somewhat smooth and idles fine except for only on three cylinders :?

Any ideas?
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Murray
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Post by Murray » Mon Apr 24, 2006 2:54 pm

Are you sure you have all the ground wires connected to the passenger-side valve cover ? there should be 2 ring terminals each with 3 wires attached for the six injectors.
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1989-75 Twinspark very sadly sold-remarkable sedan !
2014 Audi Q5 3.0l TDI - torque MONSTER
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Post by mac74 » Mon Apr 24, 2006 3:07 pm

Hmmm, the ground wires on the passenger side are connected to the AAV. I run 2.5 l-jetronic.
On the 3.0 engine when I got it, there were 2 cut-off ring terminals with each 3 wires hanging on a the bolt at the back of the valvecover.
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Barry
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Post by Barry » Mon Apr 24, 2006 8:58 pm

First thing to do here is check compression on all 6 cyl`s..Make sure basics are good..
Ive had belt jump before,no bent valves,but valves in free air doing nothing..

Check spark for each cyl. event..
Check fuel for each event..

Compression,ign and fuel at the right time,its got no option but to purrr.......
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Post by dcefali » Tue Apr 25, 2006 7:03 am

I just finished a similar swap and had trouble as well. My troubles were electric FI connections, and once the connections were right the 2.5 LJet worked great on the 3.0.

But I picked up a 3.0 AFM and loosened up the flap spring 4 notches. What a difference. I swear my GTV6/3.0 is faster than my Boxster S with a 3.2

Doug
1986 GTV6 3.0
1991 Spider
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Post by mac74 » Tue Apr 25, 2006 7:46 am

Thanks for your replies, guys....

Today I moved the ground wires (which are actually two ring terminals where one has 3 wires and the other has 2) from the AAV to the original 3.0 bolt on the valve cover. No improvement.

I can now definately tell for sure that no cylinder on the right bank fires.
If I sniff a sparkplug from the right side I can hardly smell any fuel and I guess if the injectors were opening as they should it would be quite wet, right.

Don't have the full history on the engine but it's supposed to have gone through a leaktest and a compression test at an Alfa workshop before I got it.

I'm bringing a friend tonight who is into electrics and we'll see what he can come up with.
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Barry
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Post by Barry » Tue Apr 25, 2006 8:08 am

Mac,check the 12v supplu to the right bank injectors....
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Post by mac74 » Tue Apr 25, 2006 8:18 am

Barry, will do....
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Billy
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Post by Billy » Tue Apr 25, 2006 11:43 am

Mac,

You may have no luck.
Perhaps your trouble comes from injectors blocked in place.

It happend to me a year ago (with 5 off) when I changed my engine and
belive me I checked and overchecked everything before I found out the
trouble.

So, if you have a pulse generator, I would suggest that you check if
the injectors work correctly. If you can't hear them working, try to hit
them on the side with a screwdriver (but not too hard).

I know it may sound strange but when it happend to my car, I took all
the injectors out of the engine in order to get them cleaned. But, once
the specialist pluged them on the bench they of course refused to work.
Then the guy took small hammer to make them start moving and it
worked ! He told me that it would have been a great gain of time if I
would have done that when injectors were in place.

We never know, it may work on your engine as well. Try it and tell me !

Best regards.

Billy
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Post by mac74 » Wed Apr 26, 2006 7:51 am

After checking ignition timing with a stroblight we corrected it a bit. Now it runs a lot better and on all cylinders. At least on idle. When I took it for a testdrive it kind of bogs when I open the throttle and feel powerless. Once in a while during acceleration I can hear and feel it revving like it should. When it's bad it sounds like a two-stroke engine 'four-stroking'. Can't explain it better in english ;)

Injectors messing with me? Something wrong with the ignition?


I will take it for another run tonight and check all the sparkplugs after. I'm also thinking of swapping the fuelrail out for my known-good 2.5 rail.
Any difference between 2.5 and 3.0 fuel pressure regulators?



/Mac
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Post by Billy » Wed Apr 26, 2006 10:25 am

Mac,

Before swapping the fuelrail, try as follow :

- Start the car
- Once it is idling, remove the plug from injector #1
- Check if the revving varies (or if the sound changes)
- If not, plug it back and do the same with the next injector
- Proceed this this way until injector #6

At the end, you will know if the injectors are working correctly or not.
Last comment : be careful not to break connectors while unpluging it !

Keep me informed !

Regards.

Billy
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Post by mac74 » Wed Apr 26, 2006 1:25 pm

Billy,

Tonight I started with a testdrive and since it was running ugly I killed it without letting it idle. After removing the sparkplugs I saw that the plug in cyl. 3 was wet while the others looked OK. Checked the wet one for spark, and spark there was.

Decided to swap the rail and almost went mad having to remove those stupid injector connectors once again without breaking them.

After finishing up I was prepared to have to crank for a while to get some fuel running. Only took a couple of seconds. It fired up, perfect idle and best of all really nice response when pushing the pedal!!

Only took a shorter test drive because it's late but 'mama mia' it sure feels like a different animal. Smooth and powerful with lovely music coming from the rear end.
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Post by Billy » Thu Apr 27, 2006 3:37 am

Nice job Mac !
It's always a pleasure to know that a new beast is born.
Have fun !
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