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| AFM Plate Position..?; Pics please | |
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| Tweet Topic Started: Tue Jun 8, 2010 6:16 pm (1,507 Views) | |
| cosser | Tue Jun 8, 2010 6:16 pm Post #1 |
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Hello Guys, can someone please post a picture of the AFM plate correctly set up..?? I've knocked the pin on mine down a little so the nut doesn't hit the bumpstop but now my plate looks way too low..?? Should the plate sit level with the very top of the cylinder before it bells out or another point below that..?? I had it sitting level with the very top before I knocked the pin down (about 5mm) but now its way below..?? How do I adjust the plate upwards without knocking the pin back up..and thus hitting the bumpstop again....?? Cosser..!! Edited by cosser, Tue Jun 8, 2010 7:04 pm.
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| balamb37 | Tue Jun 8, 2010 7:26 pm Post #2 |
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Grumpy Old Grampa with Dog
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If you read the 'Post' on 'mixture control' which I think is the next post there is the 'setup' instructions there
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| cosser | Tue Jun 8, 2010 8:00 pm Post #3 |
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Hey Balamb37, I have looked at those instructions,vague as they are..what I don't understand is how my plate was hitting the bumpstop when the plate was in the right position..?? I've knocked the pin in to correct this..and now the plate position is too low..?? Is there another way to adjust the plate position without knocking the pin back up..?? Do I adjust the mixture screw to bring the front edge of the AFM plate back up to the edge of the cylindrical part of the funnel..?? Cosser..!! |
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| zhenya | Tue Jun 8, 2010 8:30 pm Post #4 |
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Newbie
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Hey Cosser. Let's use the pic from my other post as a reference.![]() Note that there are essentially three colors of the venturi in my pic. The shadowed gray area near the bottom arrow I am calling the Machined Cylindrical Lip, the lighter area above that with the scribe line, and the darker area above that making the funnel. According to the instructions posted in my other thread, I believe the top of the plate must be even with the top of the Machined Cylindrical Lip at the measurement point, when pressurized by the fuel system. (Jumper the fuel pump temporarily before adjustment to make sure). It should also have 1-2mm of free play when depressing the plate before it contacts the fuel metering cylinder. How much free play do you have? Here is another picture showing the bump stop, with the plate clearly a little bit below it. You are saying yours is in constant contact? That would seem to me to be far too high and/or damaged. What is the gap around the outside edge of the plate when at rest? Can you post a picture? ![]() Be very careful about adjusting that pin down, as the only way to adjust it back up is to remove the entire unit like I have done, and even then, it is an interference fit, so adjusting it more than once or twice will cause it to be too loose, and to no longer hold adjustment. |
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| cosser | Tue Jun 8, 2010 8:40 pm Post #5 |
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Hey Zhenya, that's what I needed to know..I took my Fuel distributor off a while ago and knocked the pin back so that the plate was lined up with the funnel edge which is why it was hitting the bumpstop...!! I've knocked it down a little but looking at what you say is the measuring point..i.e. the machined cylindrical lip..I will need to give it a little more..!! On the diagram from the manual it looks like the edge of the plate is lined up to the edge of the funnel..?? Cosser..!! |
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| merc190uk | Tue Jun 8, 2010 8:45 pm Post #6 |
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The Godfather
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spot on description
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| zhenya | Tue Jun 8, 2010 9:11 pm Post #7 |
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Cosser, I'm having a little bit of a hard time understanding exactly what you have done since I think our terms might be a bit different. That's why pictures help. ![]() Are you saying you have adjusted yours high enough that it is lined up with the funnel lip, above the scribe line? (The second part in my description above?) I think that the manual is a little bit vague, as it really only shows a 2 stage transition in the funnel, when in reality, it is a 3 stage transition. 1) the cylindrical area, where you align the plate, 2) the slightly funneled shape with the scribe line, and 3) the obviously funneled part going to the top. What does the clearance around the perimeter of your plate look like? How much free play do you have? |
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| cosser | Wed Jun 9, 2010 11:55 am Post #8 |
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Hi Zhenya, I took mine off and knocked the pin out until it was aligned with the funnel..!! I've corrected it now and it's ticking over and driving a lot smoother..!! One thing..I may be wrong but I think the measuring point under the bar is for the 0.05mm gap between the plate and the cylinder wall....the plate needs to be aligned to the top of that machined lip at the front edge..!! It takes a few turns to start now but it's within 4 seconds and when it does start it goes straight to tickover whereas before,it would start after 1 or 2 turns and immediately rev to 1800 rpm before settling down to a lumpy tickover..!! I've reset the plate with a 0.05mm clearnce and adjusted the play in the plate to 2mm..!! Cosser..!! Cosser..!! Edited by cosser, Wed Jun 9, 2010 11:56 am.
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| zhenya | Wed Jun 9, 2010 2:26 pm Post #9 |
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Hey Cosser - I too may be wrong, but I have two reasons to believe the measurement point is relating to the plate height. First, the 0.05mm clearance around the edge of the plate must be equal at all points. If it is off even a hair, the plate will bind. That's why having multiple feeler gauges to set the center is helpful. I understand there was a factory tool of some sort that had 4 feeler gauges just for this purpose. Also, the bar is removed when setting the center. Second, in the manual, the measurement point is referenced in the section relating to plate height, not plate centering. Glad you are seeing improvements! -zhenya Edited by zhenya, Wed Jun 9, 2010 2:27 pm.
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| cosser | Wed Jun 9, 2010 3:07 pm Post #10 |
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Hi Zhenya, do you have that reference available to post..?? Which manual is it in..Wis?? If that is the measuring point for plate height..I've knocked the pin down too Fookin far..!! Cosser..!! Edited by cosser, Wed Jun 9, 2010 3:12 pm.
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| zhenya | Wed Jun 9, 2010 4:00 pm Post #11 |
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Same sections as I referenced in my other post - note that the section referencing the measurement point is part of Step 5 - 'check zero position.'![]()
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| stwat | Wed Jun 9, 2010 5:27 pm Post #12 |
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All of this info a more is pinned at the top of this section! |
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| zhenya | Wed Jun 9, 2010 6:55 pm Post #13 |
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stwat - yes, I know the info is pinned - that's where these pages are coming from. Sometimes it's just easier to explain something when the diagram is directly in front of us, as opposed to referencing the other post. As far as the info about setting the height - I have read the pinned post many times - and it has been very helpful - especially the section with photos of the actual components. That said, there is still considerable confusion about the actual position the plate should be in at rest - hopefully this thread will clear that up, and then maybe the relevant parts could be appended to that pinned post, if appropriate. Thanks! |
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| cosser | Wed Jun 9, 2010 7:55 pm Post #14 |
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Hey Zhenya, If you look at that diagram it shows the plate height setting at the front of the plate not at the side where the measuring point is..?? I'm going from the position of the arm in the diagram in relation to the plate which as far as I remember is in line and pointing towards the front of the car..?? If I am reading it correctly the measuring point is for the 0.05mm gap between the plate and the cylindrical part of the funnel and the 1 to 2 mm play between the control plunger and the AFM plate..??? Cosser..!! Edited by cosser, Wed Jun 9, 2010 8:23 pm.
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| zhenya | Wed Jun 9, 2010 8:44 pm Post #15 |
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I see what you are saying - yes, those two drawings do seem to contradict one another. I just can't see them going out of their way to specify where the measurement should be taken if they didn't mean it. The 0.05mm gap HAS to be taken at all points around the plate - it is intended to be centered - so using a specific measuring point doesn't make any sense. Same for the free play - that would be the same no matter where you measure it from. Can anyone else chime in on this from experience? |
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| cosser | Tue Jun 15, 2010 9:45 am Post #16 |
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Hi Zhenya, have you set your plate up using the measuring point as a reference..?? How is it running..?? Cosser..!! Edited by cosser, Tue Jun 15, 2010 9:46 am.
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| zhenya | Tue Jun 15, 2010 1:57 pm Post #17 |
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Plate has been adjusted and car is back together, but unfortunately the car is still stalling when I come to a stop. (Not every time, but sometimes). Push the clutch in, rpms drop too low, and the car almost stalls or stalls. Adjusting the plate seems to have made little difference one way or another. Not really sure what to look at next... |
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| cosser | Tue Jun 15, 2010 5:14 pm Post #18 |
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Hi Zhenya, does the car tick over O.K.? Hot and cold..?? |
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| Johnboy Mac | Tue Jun 15, 2010 5:31 pm Post #19 |
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More than part of things
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If you have'nt done, check these out. 1. Check mixture, too lean will cause idle problems. 2. Check condition of potentimeter - if it has'nt been replaced good chance it worn out. Will need to remove KE to access (well on 16V anyway) 3. Check the engine wiring loom for barkes bad connections. Hold loom at didtributor area and move. Check all earths too. 4. Check usual air & vacuum hoses. |
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| stwat | Tue Jun 15, 2010 5:41 pm Post #20 |
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Also adjust the black knob out a little on the ICV. Adjust it out a little at a time then rev the car to see how fast the revs drop. Too far in and the engine will want to stall when the revs drop. Too far out and it will take too long for the revs to drop down to normal. And make sure the engine is up to full operating temp when you do this. It may take a few attempts and test drives after adjustment to get it right. Stu |
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| zhenya | Tue Jun 15, 2010 6:38 pm Post #21 |
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Car starts right up when cold, and runs great when in gear. It's when I have to let the revs drop to idle that I have to watch it cause it might stall. I can't check mixture via duty cycle at the moment because the car is running in open-loop and I haven't figured out where that problem is. It is my understanding, however, that it does not require the electronic lambda control to run, and in fact, can possibly run better without it (I don't have emissions to pass here). Not saying that I won't fix it, just that even if I unplug the EHA the car runs exactly the same, so I am trying to focus on one problem at a time. 1) I have been adjusting the mixture in fine increments, and have gotten it to run better by doing so - it was far too rich before and seems to be ok now. I'm sure it is far from perfect. 2) Potentiometer was carefully checked while the mixture control unit was out. Appears to be good - the entire mixture control system was replaced not too many miles ago by the previous owner according to the paperwork I have. 3) I am not sure of the condition of the wiring harness in general. Every sensor I have been able to test has so far tested good. I have not yet had the opportunity to test the continuity and isolation from ground of the various wiring bits, though. On several wiring connectors I can see the insulation is a bit bad, but they do not appear to be shorted to ground or anything - just exposed to air. 4) Every hose I have looked at so far has been pliable and in good shape. Many have been replaced by the previous owner. Not 100% certain there are no vacuum leaks, but if there are, I haven't been able to find them. stawt- my understanding is that the ICV should not have to be adjusted? I have checked the ICV, and know it is functioning. That said, your suggestion sounds intriguing - right now what happens is that if the revs are high and I punch in the clutch, they drop, catch slightly around 2000, then drop down to idle. When they drop down to idle they will often go too far and almost stall or stall. It is also bouncing a bit at idle sometimes - ~900-1050 or so, back and forth. Thanks for the help all. |
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| Johnboy Mac | Tue Jun 15, 2010 7:40 pm Post #22 |
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More than part of things
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Just one other item off the top of my head, check operation of the throttle micro switch, I understand these go. |
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| zhenya | Tue Jun 15, 2010 8:14 pm Post #23 |
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Micro switch is good. |
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| zhenya | Tue Jun 15, 2010 11:21 pm Post #24 |
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ooh - new info. Prior to me pulling the mixture control unit to adjust the plate height, if I pulled the hose from the ICV to the valve cover, the idle rose immediately to 2500 rpm. Now, since putting it back together, I can pull that hose, and pretty much nothing changes... This has to be a clue, hopefully I'll have the time to look into it tonight or tomorrow. |
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| zhenya | Wed Jun 16, 2010 2:02 pm Post #25 |
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Ok, pulled the ICV valve last night. Again, checking it at 10v, it does fire, and appears to be in the correct position at rest - just slightly opened. 12v is present at the wiring connector with ignition on. However, I decided to try adjusting it to see what kind of difference it made. The adjustment screw was glued in place (is this normal? It didn't look professional enough to come from the factory this way). I was able to chip the glue out and adjust the screw, opening the valve slightly at idle. What a difference! I drove it HARD last night for nearly an hour and it didn't stall or come close to stalling once! Granted, by that time it was much cooler out than mid-day when it is usually at its worst, but still, it was good. I still have a bit a surging idle - 900-1050 or so, sometimes it settles, sometimes it hunts. Now that I think about it though, when I pulled the plug to the ICV last night and started it, the idle was nice and smooth. I'm thinking I need to pull it again and give it a good cleaning, and if that doesn't work, try replacing it. Too bad it's such an expensive part! Anyhow, this is the first real progress I've made on this irritating problem - so hopefully I'm on my way to fixing it for good! Thanks all! |
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| cosser | Sat Jun 19, 2010 6:35 pm Post #26 |
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Hey Zhenya, no way is that normal..lol..!! are you sure it was glue..?? It may have been a temporary fix for air leaking from the screw..?? Glad to hear you're getting some results for all your hard work mate..!! Idle hunting is usually a sign of weak mixture..maybe you went a little too far when you leaned the mixture out..?? Check the plugs,that should tell you if it's a bit weak..!! Cosser..!! |
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| stwat | Sat Jun 19, 2010 6:56 pm Post #27 |
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That's great news As cosser says, it should not be glued at all! It should be adjustable. It sounds like someone found a good setting at the time and then glued it! I find i have to adjust mine slightly from time to time to get the car running well again. Try richening the mixture a little to see if that helps get rid of the hunting idle. Only turn the mixture screw a few mm clockwise at a time. These valvers do seem to need regular tuning and fettling to keep them running OK. As i have found out with mine. Edited by stwat, Sat Jun 19, 2010 7:02 pm.
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| zhenya | Sun Jun 20, 2010 5:04 am Post #28 |
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Thanks guys. Yeah, this is definitely the issue - although in the back of my head I seem to remember a post somewhere that said something to the effect of "adjusting the idle speed is actually just covering up whatever the root problem is." I'm not sure if that applies here or not, but I am keeping it in mind as I continue to go through the car. In any case, the car is running very well now. I drove the snot out of it yesterday which was one of the hotter days we've seen in a while and had NO problems other than the occasional idle surge - which is now down to ~50 rpm, and not all of the time, since I cleaned the ICV. It's good to hear that the glue was not supposed to be there because it means someone else probably adjusted it at some point and/or as you noted Cosser, they were trying to stop a leak or something. I am leaning towards replacing the part now, despite the cost, as it appears that the ICV can cause issues even if it 'tests' ok. Also, there appears to be a direct relationship between the OVP and the ICV, so they may both get replaced. Anyhow, the car now has new injectors, new plugs, new cap and rotor, new air filter, adjusted the ICV and the air flow plate, and it is no longer stalling AND it starts back up just fine when hot. The previous owner warned me that it hadn't liked starting hot in as long as he could remember - you had to floor it to start it - and now it is starting the same hot or cold! Now on to tackling the rest of the electrical emissions system to figure out why the car is running open loop. Thanks so much! It's great to have it running! |
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| cosser | Sun Jun 20, 2010 1:50 pm Post #29 |
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Hey Zhenya, where did you set the AFM plate height to..the measuring point or the front of the plate..?? Cosser..!! |
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| zhenya | Sun Jun 20, 2010 9:36 pm Post #30 |
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Measuring point. |
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| cosser | Sat Jun 26, 2010 12:10 pm Post #31 |
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Hey Zhenya, It looks like it's metering head off... again.... for me then..lol..!!...why am I laughing..?? Cosser..!! |
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| zhenya | Mon Jul 12, 2010 8:17 pm Post #32 |
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did you ever get around to looking at this again Cosser? How's the car running? We are in the midst of the hottest weather we have seen here in years and I'm happy to report that everything is running tip-top! |
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| cosser | Wed Jul 14, 2010 7:58 am Post #33 |
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Yes mate, I didn't have time to take the metering head back off so in the meantime I took off the AFM plate and replaced it with the washer underneath the plate to raise it a mm or 2 as a temp fix..!! car runs a lot better..starts better just a little issue with the idle dropping too low intermittently but i think that's an electrical issue..?? I'll be taking the metering head off at the weekend to reposition the plate properly..!! I found a piece in the Wis which categorically states that the Top edge of the AFM plate must be aligned to the Top edge of the cylindrical part of the funnel "At The Measuring Point"..!! Cosser..!! |
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