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Runs rich, wont rev past 2-3k


240DL?

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I am currently voltage testing the potentiometer on both of my AFM's. The vane on number one drops as in the video, but the voltage starts at nearly half of the input. 

Does this sound right?

I connected a 9 volt battery to pin 9 and pin 6 of the AFM, connected a voltage meter inside the case to pins 8 and 7. Pins 9-6 input 8.75 volts but 8-7 reads 4.5 volts when all the way closed. As I move the flap it drops as described. Should the voltage at pins 8-7 with the AFM closed be the same as the input of 9-6? 

The resistance at 8-7 on the AFM shows a resistance of 163 ohms? I'm reading now this should be near continuity

Edited by 240DL?
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don't get too hung up on the absolute voltage readings. I was just looking for breaks or large deviations while sweeping the trace. you just want the voltage setup on the lowest and the highest part part of the trace then check the voltage by reading one end of the trace  and the center wiper. As you sweep you should see the voltage ramp up as you approach the end of the trace. if you have other AFM just repeat your setup and see if they all behave about the same.

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try battery voltage at 6 and 8, then read from 6 and 7 and sweep. you should see a lower voltage as you approach 6 and a ramp up as you approach 8. again absolutes are not what you are looking for just a relatively smooth ramp go slow since you have digital. there are fixed resistors in there that make voltage division with out any sweep. see if you get the same results on the other AFM's. if that seems smooth then that clears the trace of any opens, just compare the fixed resistance readings on 6 to 8 and 8 to 9 between all the AFMs.

compare the "feel" of the flap spring resistance of all the AFM's are then about the same?

 

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BTW the go to problem for everyone that 1st starts in on EFI is messing with the AFM, these test will hopefully clear that as a major problem. Frankly I would bet its NOT the problem, just something else overlooked. this is what ZH was talking about, you need to read the fuel pressure at static no vacuum (36 psi), idle (30psi), the ohms from the temp sensor and what temp the coolant is, compare to the table. I just don't want you to overlook anything, the hard numbers will help reassure those trying to help that you are not missing anything. I see no reason not to swap another AFM if you have it just to see if there is any change. hopefully that will be it, but again its prob not unless it has been seriously monkeyed with. who knows it could just be a massive injector leak, a fuel pressure test after shut down will show that, it should hold and least for a few minutes. If the pressure goes away INSTANTLY then clearly a leak, also the FPR's have been know to leak, pull the vacuum line and see if its dripping. seems like it would have to be massive for the kind of problems you are having.

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4 hours ago, Dave WM said:

BTW the go to problem for everyone that 1st starts in on EFI is messing with the AFM, these test will hopefully clear that as a major problem. Frankly I would bet its NOT the problem, just something else overlooked. this is what ZH was talking about, you need to read the fuel pressure at static no vacuum (36 psi), idle (30psi), the ohms from the temp sensor and what temp the coolant is, compare to the table. I just don't want you to overlook anything, the hard numbers will help reassure those trying to help that you are not missing anything. I see no reason not to swap another AFM if you have it just to see if there is any change. hopefully that will be it, but again its prob not unless it has been seriously monkeyed with. who knows it could just be a massive injector leak, a fuel pressure test after shut down will show that, it should hold and least for a few minutes. If the pressure goes away INSTANTLY then clearly a leak, also the FPR's have been know to leak, pull the vacuum line and see if its dripping. seems like it would have to be massive for the kind of problems you are having.

My fuel pressure is 31psi pump running no vacuum, and 29 at idle. The fuel pressure gauge does show an immediate drop in fuel pressure after the pump turns off. I pulled the Fuel pressure regulator vacuum line and ran the pump with no sigh of gas (vapor or liquid) so I pulled the rail. With the pump running no injectors leaked. After crimping the line following the fuel filter on it's way to the rail the pressure holds. My guess would be either a leak before that or the check valve in the (aftermarket) pump installed by the PO. 

 

Here are the results of the tests I have done 

1.      TPS idle (2-18)

Throttle released    = continuity

Throttle depressed = none

 

2.      TPS full throttle (3-18)

 Throttle released   = none

Throttle depressed = continuity

 

3.      AFM resistance 1 (6-8) 180 ohms

AFM 1 = 183.6

AFM 2 =185.7

4.      AFM resistance 2 (7-8) continuity  (small resistance)

AFM 1 =163.4

AFM 2 =none?

5.      AFM resistance 3 (8-9) 100 ohms

AFM 1 =102.3

AFM 2 =103.8

6.      AFM air temp sensor (6-27)

AFM 1 at xf =2940 at about 60f

AFM 2 at xf=air temp sensor seems to be damaged

7.      AFM fuel pump contacts (10-20)

AFM 1 closed=none

AFM 1 open =continuity

AFM 2 closed=none

AFM 2 open =continuity

8.      Water temp sensor resistance (13-ground)

Cold =2750 ohms

Warm = 330 ohms at 170f

9.      Fuel pump relay circuit (20-ground)

Continuity? = 68 ohms

10.  Air regulator and fuel pump circuit (34- ground)

Continuity? = 79 ohms

11.  Control unit ground (5-ground)

Continuity? = continuity

12.  Control unit ground 2 (16-ground)

Continuity? = continuity

13.  Control unit ground 3 (17-ground)

Continuity? = continuity

14.  Control unit ground 4 (35-ground)

Continuity? = continuity

15.  Ignition coil trigger input signal (1-ground) ignition on

Battery Voltage? = 12.23/12.35 slight drop

16.  Control unit power input circuit (10-ground) ignition on

Battery Voltage? =yes

17.  Injector 4 (14-ground) ignition on

Battery Voltage? =yes

18.  Injector 1 (15-ground) ignition on

Battery Voltage? =yes

19.  Injector 5 (30-ground) ignition on

Battery Voltage? =yes

20.  Injector 6 (31-ground) ignition on

Battery Voltage? =yes

21.  Injector 3 (32-ground) ignition on

Battery Voltage? =yes

22.  Injector 2 (33-ground) ignition on

Battery Voltage? =yes

23.  Start signal (4- ground) key to start

Battery Voltage? =yes

 

 

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5 hours ago, 240DL? said:

4.      AFM resistance 2 (7-8) continuity  (small resistance)

AFM 1 =163.4

AFM 2 =none?

well looks like AFM 2 is a problem,  I will dig out my spare and see what I get on 7-8 and see if I get the same "small" or near that. I assume that was with the flap in the closed (since 7 is a movable contact). Will get back to you later. AFM 1 is what you have in the car right?

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