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Rev limits at exactly half what it's set to

did you check to see if the tooth was in front of the sensor when the led came on for step #5? im suspecting the window was in front of the sensor when the light was on if that is the case then your megasquirt board is wired for a high to low type of hall sensor and you will need to change that.
 
Magnum TE said:
and did you check the timing with the light to confirm that it stays at the fixed angle ad various RPMs
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Yup.
Magnum TE said:
Is it still rev limiting at 3500rpm?
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Depends on timing, engine temp, ambient air temp, etc. but generally it's around 4500 now.
Magnum TE said:
Please don't be insulted, but do you have the plug wires setup correctly?
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From left to right on the cap it's 4-3-1-2, yes?
burstcurse said:
did you check to see if the tooth was in front of the sensor when the led came on for step #5? im suspecting the window was in front of the sensor when the light was on if that is the case then your megasquirt board is wired for a high to low type of hall sensor and you will need to change that.
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I did not. Do I need to pull out the black dome piece to see it?
 
yea you might have to thake the rotor and the black cover off to see it ther is a metal rotor with 4 teeth that pass through the hall sensor.

I think that your trigger angle is too low(10 degrees) because the hall circuit is built to read the wrong edge of the teeth on the wheel in the distributor.

or you could compaire the jumpers on the ms board with the options in the megasquirt documentations to see whitch way it was built. the circuits Ive posted above are the correct way to wire ms for bosch hall sensors.

ive had them built wrong before but I use msII now and it has an option to select a high or low input.

the way I see it you will either have to rewire the ms board for the correct hall circuit or pop in a msII chip
 
I'm about to check right now. If it is the wrong way around could I put a different distributor in there? I didn't build the MS board I'm using and I have absolutely no interest in taking it apart/breaking it.
 
Couldn't get the rotor off to get the black dome off, so I pulled out the whole dizzy. The distributor shaft (I'm guessing that's what it's called?) wasn't spinning freely and was kind of clicking into place. Got the rotor off and found that the hall sensor is loose and rocks back and forth, but usually has the inner magnet against the inside of the veins. :| So maybe found the problem? A problem?
 
Went back out and completed steps 1-5 with the cap and dome thing off. This is where the vein was located.

2moypds.jpg
 
so your light is coming on over the hole rather than the metal tooth.

if you don't want to rewire the ms then I guess the easiest solution would be to get a msII chip because it can be set to read the rising edge or the falling edge of the wheel. I don't believe the msI code has that option.
 
or I just thought of this try a much higher number for the trigger angle like 110* and leave the distributor where it ran at 10* this will make the previous tooth be the trigger for the next one and you will have a high enough trigger angle to get advance in the higher rpms.

enter 87.5 then use the 22.5 addition box
 
I don't think the plug can go on backwards? I talked to Silver/Matt about reversing the wires and the consensus was that it wouldn't change the signal from 0v -> 5v to 5v -> 0v, but would actually change it to -5v -> 0v or the other way around.
 
I can't remember, you've changed that dizzy out completely right? For a known good working one.

Do you know someone with a LH2.2 740 to drop that one in?

I know the failed head mounted lh2.2 dizzys I've had were a complete failure, not an intermittent/strange running problem. It's worth a try if you have a lh2.2 740 you can tap.
 
Trigger angle: 10
Trigger angle addition: 0
Cranking timing: Time based
Cranking angle advance: 10
Hold ignition: 1
Spark output inverted: No
Oddfire: No
Fixed angle: -10
Trim angle: 0 (Normally this is -7 while driving, I set it to 0 for the sake of troubleshooting)
Car starts and idles 'normally' (this is my normal setting).

Trigger angle: 88 (87.5 automatically rounds up)
Trigger angle addition: +22.5
Cranking timing: Time based
Cranking angle advance: 10
Hold ignition: 1
Spark output inverted: No
Oddfire: No
Fixed angle: -10
Trim angle: 0
Engine cranks a few times then stops; sounds like something is preventing it from spinning. Additional attempts are crank, crank, tries to start, makes weird noise (like when you try to start a running engine?) and stops.

Trigger angle: 88
Trigger angle addition: +22.5
Cranking timing: Trigger return
Cranking angle advance: n/a
Hold ignition: 1
Spark output inverted: No
Oddfire: No
Fixed angle: -10
Trim angle: 0
Sometimes starts after cranking for a while with throttle open, runs like butthole, then stops.

Trigger angle: 65
Trigger angle addition: +45
Cranking timing: Trigger return
Cranking angle advance: n/a
Hold ignition: 1
Spark output inverted: Yes
Oddfire: No
Fixed angle: -10
Trim angle: 0
Starts almost instantly, seems to idle pretty well, can't get it timed by moving the distributor. Trying to rev make the engine want to die.

Trigger angle: 75
Trigger angle addition: +45
Cranking timing: Trigger return
Cranking angle advance: n/a
Hold ignition: 1
Spark output inverted: Yes
Oddfire: No
Fixed angle: 10
Trim angle: 0
Little bit harder time getting started, timing is almost correct but the timing light doesn't seem to be firing half the time and the mark wobbles. Trying to rev make the engine want to die.

Trigger angle: 65
Trigger angle addition: +45
Cranking timing: Time based
Cranking angle advance: 10
Hold ignition: 1
Spark output inverted: Yes
Oddfire: No
Fixed angle: 10
Trim angle: 0
Seems to start and idle a bit better, timing is still off ~10-15 degrees, still doesn't want to rev.

Trigger angle: 80
Trigger angle addition: +45
Cranking timing: Time based
Cranking angle advance: 10
Hold ignition: 1
Spark output inverted: Yes
Oddfire: No
Fixed angle: 10
Trim angle: 0
Starts okay, idles fine, timing is almost spot on but wobbles slightly. Still doesn't want to rev.

Pretty sure the distributor came off my old engine since the new engine came out of a 2.4 car. My buddy has a lead on a distributor for me to throw in so we'll see how that goes.
 
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Increased the req_fuel from 14 to 16 and set the trim angle back to ?0 and it drove normally up to just past 4,000 where it hesitated/misfired per usual. It's an improvement since before I had to run from -5 to -10 to get it to drive without backfiring as soon as I pull out of the driveway.
 
High pressure in-line is brand new. The in-tank pump's sock is clean, not sure how well the pump itself works. I have a Walbro that needs to go in.
 
I got the MS as a 'kit' from Poik who built it following this guide: http://forums.turbobricks.com/showthread.php?t=121163

I'm following the steps to try make sure that everything is wired up correctly. Bold steps are ones that I verified to be correct, non-bold I haven't looked into yet.


500dollar744ti said:
1) Pin 1 from the existing AMM connector is already grounded for you and it goes to ground on the IAT sensor.

2) Pin 6 on your existing AMM connector is the signal line for the IAT sensor going to MS.

3) Go into the fusebox and remove the brown wire that supplies power to Fuse #1, splice it into another power wire that is on switched 12v from the ignition switch when it is in the run (II) position. Make sure whatever source you use is fused, (I used the blue/red feed going to the fuse directly below Fuse #1 because that is switched 12v) This is VERY important, if you skip this step your fuel pump will run at all times when the key is off and cause horrible flooding in the cylinders.

4) The stock overpressure switch remains in place so if you want to use it, leave it there, if you have not already bypassed it and don't want to use it, do it now.

5) Pin 1 of the IAC is TPS signal. (IAC is not used here, adjust idle with thumbscrew on throttle body!) This leaves you with two pins running to the IAC connector if you wish to add the bosch 2-wire IAC in the future.

6) Pin 2 of the stock TPS needs to be removed, next move wire from IAC pin 1 (step 5) to this hole, do it whatever way pleases you, I used a black wire and covered it because that looks nice.

7) Swap the wire that was originally in TPS pin 2 here (empty hole for pin 3). IT HAS BEEN FOUND THAT DEPENDING ON YOUR TPS CLOCKING PINS 1 & 3 MAY NEED TO BE SWITCHED IN ORDER TO OBTAIN CORRECT TPS SIGNAL!

8) EZK box- Volvo has already run the wires you need to go from the EZK connector to the LH2.2 connector so this makes things simpler!

9) This pin is your WB02 input to megasquirt, it is the little jumper in the harness next to the LH box. It is a simple spade connector and I used it because it makes wiring O2 output to the adapter wiring easy. If you want to use your STOCK O2 sensor, MS pin 23 will need to go to LH pin 20 instead of 19 which is where i have it in the pinout.

10) EZK jumper wire from pin 8 to 24, redirects dizzy signal line to megasquirt using the stock wires.

11) Jump pin 6 to 4 with 10 ohm resistor inline, supplies dizzy power using stock wires. I did this all inside an old EZK box but drew the line outside because it is easier to see.

12) Jump pins 12/10 to pin 20 to supply ground for the dizzy and knock sensor. I do not have a knock sensor wired to MS but if i ever choose to, this will already have it grounded for me.

13) Jump pin 17 to 16, this redirects ignitor module signal back to MS.

14) Pin 5 needs to be moved to pin 6 when using a Saab 139.

15) Saab (Bosch) 139 module, get one from a 900/9000 turbo, it's located on the driver side fender near the strut tower.
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The TPS-related stuff would be in bold but after I took out the harness and put it back in (to loom and fix rotten insulation) it stopped working. I probably have the wires wrong, but it shouldn't have anything to do with the rev problem, especially since it was doing this when the TPS worked.
 
Do you have a wideband or narrowband gauge hooked up?

You can always reset your TPS thresholds. It might maybe could be thinking that you're giving it either more or less throttle than you actually are, and then routing that through your VE table and giving you crappy fuel which would stop you from freely revving.
 
kahlua240 said:
You can always reset your TPS thresholds. It might maybe could be thinking that you're giving it either more or less throttle than you actually are, and then routing that through your VE table and giving you crappy fuel which would stop you from freely revving.
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TPS isn't a factor in the VE equation on MS.
 
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