 Posted: Tue Apr 27, 2010 7:46 pm Post subject: |
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All looks correct, i cant take any pipes off the plastic spider as i'm scared that it will snap. i have blown down the FPR pipe and can hear air come out of all TB's  I can't figure it out. |
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| Posted: Tue Apr 27, 2010 10:03 am Post subject: |
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| Hi
All I can suggest is taking the pipe off from the fpr to the manifold and checking it is clear, along with the connection on the manifold. And double checking it is attached after the throttle body. All the best Keith |
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| Posted: Mon Apr 26, 2010 4:29 pm Post subject: |
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| I tried closing all the idle bypass screws, no difference to fuel pressure, tried at 1 turn out, then 2, then 3, made no difference. Then i put back to where they were.
If you look at theis video http://www.youtube.com/watch?v=MmPNQhYsTJ4 kindly posted by a helpfull member, you can see that there is enough vacuum to hold the FPR pipe to his finger, there is not on mine. |
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| Posted: Mon Apr 26, 2010 4:14 pm Post subject: |
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| Hi
From experience with a bike, getting the throttle body sync miles out got them to appear close to being in sync. However if they are in sync then that suggests that none of the throttle bodies have any vacuum at idle which is pretty much impossible. All the best Keith |
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| Posted: Mon Apr 26, 2010 3:49 pm Post subject: |
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| I have done a compression test, back 2 are same, front 2 are the same, all above minimumand within tollerances. TB's synced ok.
Throttle stops adjusted to 10 thou, 1/4 turn from closed, also tried at 3/4 turn. |
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| Posted: Mon Apr 26, 2010 8:32 am Post subject: |
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| Hi
Can't see how with a closed throttle you can avoid having a half decent vacuum on that cylinder, unless the throttles are well out of sync (or compression is non existent in that cylinder). All the best Keith |
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| Posted: Thu Apr 22, 2010 10:55 am Post subject: |
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| With the engine off, the plenum chamber off too and the pipe off to the FPR i can hear air in all 4 TB's when i blow down it, i checked all pipes to TB's they look good, also checked pipe to carbon canister all good, im stumped. |
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| Posted: Wed Apr 21, 2010 7:55 pm Post subject: |
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| Hi
I would check that the pipe is clear. Possibly remove the pipe to the fpr and with the engine at idle squirt something like cold start down the pipe to the inlet. If it affects the revs the air can get through. All the best Keith |
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| Posted: Tue Apr 20, 2010 11:20 pm Post subject: |
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| Keith, My fuel pressure is at max all the time due to no vacuum causing it to drop. I agree with lack of vacuum and can't for the life of me pin point it, everything looks connected correctly. | |
| Posted: Tue Apr 20, 2010 2:59 pm Post subject: |
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| Hi
It shouldn't matter. If you have no intake vacuum then the fuel pressure should be at max. The reason you have the fpr connected to the intake for pressure is so that the pressure difference between the intake and the fuel pressure is constant, so that the length of time the injector is open is directly proportional to the amount of fuel that flows. The actual pressure is (within reason) irrelevant. However there should be a large vacuum at idle with the throttle closed. That there isn't suggests that either the vacuum pipe / takeoff is blocked or the vacuum pipe has been connected to the intake before the throttle. All the best Keith |
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| Posted: Sun Mar 07, 2010 8:21 pm Post subject: |
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| My fuel pressure is at the max and drops if i suck on the FPR.
I am getting no vacuum on idle so fuel pressure is on max, when it should be on min. 
Fuel pressure should be min on idle and max on WOT Mine is max all the time, hence running slightly rich. |
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| Posted: Sat Mar 06, 2010 11:15 pm Post subject: |
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| Hi
Put it this way, I would expect about 30~40psi fuel pressure at low vacuum, and when the vacuum in the intakes 'increases' I would expect that to drop. Without intake vacuum the fuel pressure should be at the max. All the best Keith |
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| Posted: Thu Mar 04, 2010 1:35 pm Post subject: |
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| ?? | |
| Posted: Thu Mar 04, 2010 11:24 am Post subject: |
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| Hi
Wouldn't expect the fuel pressure regulator to really do anything at idle. All it does is maintain the fuel pressure at X psi above intake air pressure (basically to make mapping easy, as if the difference in pressure is constant then the amount of fuel injected is pretty much directly proportional to the time the injectors are open). As such if the intake vacuum is nominal then no need to drop the fuel pressure. Not sure on the throttle body issue. I can see that having one bypass closed and the other slightly open could easily balance a pair of throttle bodies, you would then need to balance each of the pairs against each other by adjusting the linkage. Either way though, as long as they are balanced then they shouldn't affect the mixture as they are taking effect long after the air flow meter. All the best Keith |
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| Posted: Wed Mar 03, 2010 12:37 am Post subject: |
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| I mentioned that maybe there is not enough vacuum being produced to cause the FPR to drop the fuel pressure on tick over. I think I am right.
I tested the fuel pressure again today and removed the vacuum pipe and it made no difference. This time I put some vacuum pipe on the FPR, gave it a suck and saw the fuel pressure drop by 5 bar as it should. When I mentioned this to my Alfa garage, they said that one idle bypass screw per side of the TB's should be closed and the other one is use with the manometer to balance out each side, I wish they said this before  mine were both open.
Does this not seem strange as one cylinder per side will be unbalanced with the cylinder on the same side??? |
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| Posted: Mon Mar 01, 2010 2:42 pm Post subject: |
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ok guys 
What do you / other people need to know I am trying to figure out why my CO is higher than the maximum of 0.3% on fast idle. Fuel pressure regulator, Throttle body butterfly stop adjustment / idle mixture screw adjustment, air leak? |
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| Posted: Mon Mar 01, 2010 2:18 pm Post subject: |
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| nope, never read them and don't have a clue or a cat |
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| Posted: Mon Mar 01, 2010 2:09 pm Post subject: |
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| I read them Al, It's just that I haven't got a f***ing clue what you're going on about |
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| Posted: Mon Mar 01, 2010 1:51 pm Post subject: |
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| Is anyone reading these pages anymore? |
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| Posted: Mon Mar 01, 2010 1:42 pm Post subject: |
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| Is anyone reading these pages anymore? |
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| Posted: Sun Feb 28, 2010 1:07 pm Post subject: |
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| Any one??
Have i missed anything? |
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| Posted: Fri Feb 26, 2010 7:40 pm Post subject: |
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| I have since adjusted the butterfly stops on the throttle stops, this cured my slow tick over when cold, checked compression and spark plug gaps and I will do another fuel pressure test. My thinking is that as the butterflies were closed too much, not enough air was passing the pipes to the plastic spider thingy and therefore not making enough vacuum for the FPR to drop the pressure on idle, what do you think?
I had another emission test today and borrowed the proper Alfa tool to be able to do a pre cat test. I got the following.
I adjusted the Volts on the idle mixture screw from the default 2.55V and set it to 4.58V to get the CO down from 3.2 to 0.69. The manual says between 0.6 and 1.0. Where there are “?” I forgot to test, DOH! The emission tester doesn’t think it’s the cat as the HC’s are good and the CO would be much much higher if the cat had gone, he thinks slight over fuelling. Could there still be an air leak, injector, FPR problem?? Keith could you look at the "code" section as it is not appearing correctly, what am i doing wrong? Thanks Alan |
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| Posted: Wed Sep 16, 2009 2:24 pm Post subject: |
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| I had to let si calm down after his cursing session before confirming the following.
When revving the engine the fuel pressure dropped, i believe this to be wrong and think it is either a vacuum leak or the FPR is faulty. If the fuel pressure drops there is not enough fuel going in, does the ECU detect this from the lambda sensor and increase the injector duration? If it does could it be that it cant get it quite right and is just over fueling? |
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| Posted: Mon Sep 14, 2009 6:26 pm Post subject: |
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| Big thanks to Simon at Formula One for doing the test after hours. I had to listen to him curse at alfa's for not being normal
The pressure is at it should be 2.9 3.0 bar. Only other thing to do is replace the injectors with some that were on a car that passed emissions, as i cant think of anything else. |
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| Posted: Fri Aug 21, 2009 10:33 am Post subject: |
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| I think we did the measurement wrong, Than tried to explain it to me last night but i could not get my head around it. With the help of bianco i belive i now understand what Than was trying to say.
We need to connect an inline fuel pressure gauge anywhere in the rail, eg, after the dampner. The way we connected it was incorrect because with no return going back to the tank you are taking away the ability to dump fuel pressure via the return line, so i guess i have to do it again, DOH! Paul hold fast it might still be a problem. |
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