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I could sure use some good advice aligning the engine up at TDC.

When I first set the camshafts up, I aligned both cam bearing marks at the very top. After starting the engine, it it didn't run real smooth -nor would it idle.
I went back and checked it and noticed that the cam bearing timing mark for the intake camshaft is off center (too the left if facing car). Therefore I readjusted the intake camshaft so that the cam bearing mark and camshaft are aligned.

It actually runs worst.

I have followed the setup as per the manual. I have the pulley lined up on the mark with the distributor pointing toward # 1 cylinder. I also have both camshafts lined up with the cam bearing mark. The engine will run but not smoothly and will not idle.

It will not run very and sometimes backfires. I would appreicate any help.:001_smile:
 

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I could sure use some good advice aligning the engine up at TDC.

When I first set the camshafts up, I aligned both cam bearing marks at the very top. After starting the engine, it it didn't run real smooth -nor would it idle.
I went back and checked it and noticed that the cam bearing timing mark for the intake camshaft is off center (too the left if facing car). Therefore I readjusted the intake camshaft so that the cam bearing mark and camshaft are aligned.

It actually runs worst.

I have followed the setup as per the manual. I have the pulley lined up on the mark with the distributor pointing toward # 1 cylinder. I also have both camshafts lined up with the cam bearing mark. The engine will run but not smoothly and will not idle.

It will not run very and sometimes backfires. I would appreicate any help.:001_smile:
you need to find true mechanical top dad center. you could be pretty far off using distributor marks and the front pully marks can be confusing.

clean out the area around all the plugs and then take all the plugs out. stick a straw down #1 hole and either turn the fan by hand while pushing on the belt or put the car in gear and push it a bit until the straw move as far as its going to go up and then back it up a bit and do it again and do that until you get a feel for where top is. then look at the front pulley and the pointer should be pretty close to a mark. that's tdc. put it on the mark , put your cams where they actually belong and youre done.
 

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I also have both camshafts lined up with the cam bearing mark
you probably got it right:).... but, just in case (as cams have 2 marks 180° apart)

front cam lobes (cyl #1) should point out away from one another on TDC.
 

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you probably got it right:).... but, just in case (as cams have 2 marks 180° apart)

front cam lobes (cyl #1) should point out away from one another on TDC.

right about this. forgot to mention ( as pointed out ) that both #1 cam lobes should be pointing away from the center of the motor at tdc firing # 1 ... the 180 deg marks are usable but the car was set up originally on the 0 deg ones.
 

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Discussion Starter #5
right about this. forgot to mention ( as pointed out ) that both #1 cam lobes should be pointing away from the center of the motor at tdc firing # 1 ... the 180 deg marks are usable but the car was set up originally on the 0 deg ones.
I did check TDC with a long wooden dowel to verify the pulley lineup was correct. Also, both cam lobes are pointing away from the center as mentioned. I will continue to try to determine what is amiss.

Really appreciate the help!
 

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I think it'd be wise to describe the background as to what work you have been doing (you say "when I first set the camshafts up")....and whether before this work the car was actually running fine ?

(what model btw? you say motronic, so an S4 spider?)...there is not much fiddling with the timing you can do on an S4 apart from setting TDC (as you have, it seems) and getting the leads in the right order in the distributor cap....(1-3-4-2)
 

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Discussion Starter #7
I think it'd be wise to describe the background as to what work you have been doing (you say "when I first set the camshafts up")....and whether before this work the car was actually running fine ?

(what model btw? you say motronic, so an S4 spider?)...there is not much fiddling with the timing you can do on an S4 apart from setting TDC (as you have, it seems) and getting the leads in the right order in the distributor cap....(1-3-4-2)
The car is a 1991 S4 and was running good prior to me doing any work.
The work I was doing on the car was checking the valve clearance and removed the exhaust camshaft to inspect one of the tappets.
 

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The car is a 1991 S4 and was running good prior to me doing any work.
The work I was doing on the car was checking the valve clearance and removed the exhaust camshaft to inspect one of the tappets.
In order to do that you had to remove the intake hose and AFM so make sure all the connections are secure, that you don't have an intake leak from either the bellows or the hook ups for idle stabilizer, Oil Vapor Separator, fuel pressure regulator or cruise control (if you have it). The intake hose can develop cracks so inspect it closely. Any intake leak past the Air Flow Meter will throw the whole system off.
 

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.....nor would it idle....I went back and checked it and noticed that the cam bearing timing mark for the intake camshaft is off center. Therefore I readjusted the intake camshaft so that the cam bearing mark and camshaft are aligned.
can you run us through just how you did this? did you loosen the VVT (Variable Valve Timing) cog to do this? (I ask, because you need some fairly big wrenches to do this!)
http://www.alfabb.com/bb/forums/5271625-post205.html

a bad (as in 'stuck on') VVT will give you v. rough idling, practically conking out, as it advances the intake cam by some 7°

.......can you look thru the inspection hole on the VVT and see if the plunger is stuck in? (ie. you see a big space between solenoid tip and plunger tip)......you can remove the 2 wire connectors under the rubber boot, and simply apply 12V + and - to the two terminals (any way round works) and see if
a) the solenoid clicks out and pushes the little plunger in
b) the plunger follows the solenoid back as it retracts.
and
c) the idle gets (even) worse?

Obviously double & triple check for air leaks as Paul above says.......this is imperative for the smooth running.
 

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If you use a bright lamp and look very carefully, you will notice the cam caps are stamped 1-6, beginning with the front exhaust cap, proceeding to #3 at the rear, across to #4 on the rear of the intake cam and ending at #6 on the front intake cap.

Just sayin'
 

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Comments were not meant to insult or ridicule.
Having been on the other side of such comments, I can tell you that intent doesn't mean squat. When someone posts a question that clearly implies: "I did something wrong, I've done my best to trouble-shoot, and I now need help figuring out my error based on the symptoms I'm seeing," someone will always respond with "You need to realize that you did something wrong." Such answers are at best useless, and at worst, an implication that the original poster is so arrogant or simple-minded as to have never entertained the thought that the problem rests in a recently-bungled repair. In this case, regardless of the intent behind these posts, it appears that the original poster has left the building.

I can only imagine what some of you say when asked "Does this dress make my butt look big?" :001_tongue:
 
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