Is the map wire the correct one to cut for installing a fuel cut lifter ? map wire in pic below MY97/98

http://homepage.ntlworld.com/b.ruces...7ecupinout.jpg

I have cut the map one but doesn't appear to make any change with the lifter...
Bit stuck, as it should be working......


Cheers
Hakon

 

Apologies, link now working...

 

Yes, the map wire is the correct one to cut, then you put the fuel cut lifter between the two ends.

When you say it doesn't make any change what do you mean? Does the engine still cut out at the same boost pressure?

Matthew

 

Matthew

I have followed the supplied instructions but whenever I adjust the dial away from normal ( 12 ) to say ( 10 ) it seems to lower the fuel cut and adjusting it to ( 7 ) causes the engine to run badly under slight boost. It feels as if the choke has been pulled out as on a carb engine. I thought I might have wired it the wrong way round but it wasn't the case. I have checked all the four wires at least twice but can't see any problems.......


Cheers
Hakon

 

Hakon

What have you done to raise the boost pressure?

All a fuel cut lifter will normally do is stop the map voltage reaching the ECU from exceeding the value that causes the fuel cut. If you do hit fuel cut it is pretty unmistakable - as though you've slammed your foot on the brake when at full throttle. It sounds as though turning the dial to a lower number sets the clamp voltage lower, which means that with it at 7 the ECU is seeing less boost than the turbo is actually providing and the engine is quite likely to be running lean.

If you have a digital voltmeter and can attach it to either side of the lifter then you should be able to read the signal to the ECU and see if it's being clamped. It's best to get someone else to drive while you're doing this as attempting to steer while looking at a meter on the passenger seat could end up in a nasty accident.

Matthew

 

Thanks for the reply Matthew,

I had an Apexi avc-r set up in the summer to 1.0 Bar, since it has been getting colder I have run into fuel cut on a number of occasions. Two weeks ago I bought a Hks fuel cut defencer so as to lift the cut just a little while still maintaining the same settings on the avc-r and possibly at a later date increase the boost a little... maybe
Anyway, I played with the fuel cut defencer to see if it lifted it, I didn't notice much on settings 11 and 10 and the car ran progressively more lumpy the lower the setting 9-7. ( Didn't play with more than a couple of psi in case of trouble) Since then, I have kept it on 12 (norm)
I turned the avc-r start duty function down a little as the boost was overshooting and is now not hitting the cut.
Still a bit unsure as to why the cut defencer is not working. Does it actually change the fuel cut level that much ?
It was set up with det cans and wideband as I think you can never be too careful and I have knocklink and Afr on the car.
What sort of voltage changes should I be looking for, regarding cut lifter..?

Thanks
Hakon

 

Where are you taking the map input to the avc-r from? If it is on the ECU side of the fuel cut defencer then it will see the limited voltage and won't work correctly.

I don't know how sophisticated the HKS version is, but a basic fuel cut defender just clamps the maximum voltage seen by the ECU so fuel cut never happens! A more sophisticated approach is to scale the voltage so you still have a limit, but it is at a higher value.

Matthew


Pre96 Map Sensor Scale

kPa mmHg PSI Bar mv
-26.7 -200 -3.87 -0.267 2100
-21.36 -160 -3.096 -0.2136 2200
-16.02 -120 -2.322 -0.1602 2300
-10.68 -80 -1.548 -0.1068 2400
-5.34 -40 -0.774 -0.0534 2500
0 0 0 0 2600
5.34 40 0.774 0.0534 2700
10.68 80 1.548 0.1068 2800
16.02 120 2.322 0.1602 2900
21.36 160 3.096 0.2136 3000
26.7 200 3.87 0.267 3100
32.04 240 4.644 0.3204 3200
37.38 280 5.418 0.3738 3300
42.72 320 6.192 0.4272 3400
48.06 360 6.966 0.4806 3500
53.4 400 7.74 0.534 3600
58.74 440 8.514 0.5874 3700
64.08 480 9.288 0.6408 3800
69.42 520 10.062 0.6942 3900
74.76 560 10.836 0.7476 4000
80.1 600 11.61 0.801 4100
85.44 640 12.384 0.8544 4200
90.78 680 13.158 0.9078 4300
96.12 720 13.932 0.9612 4400
101.46 760 14.706 1.0146 4500
106.8 800 15.48 1.068 4600
112.14 840 16.254 1.1214 4700
117.48 880 17.028 1.1748 4800
122.82 920 17.802 1.2282 4900
128.16 960 18.576 1.2816 5000

MY97- Values.....

Bar Map sensor output (volts)
0.0 2.29
0.1 2.44
0.2 2.58
0.3 2.73
0.4 2.90
0.5 3.03
0.6 3.18
0.7 3.33
0.8 3.47
0.9 3.63
1.0 3.78
1.1 3.92
1.2 4.07
1.25 4.13
1.3 4.21
1.4 4.36
1.5 4.52
1.6 4.67
1.7 4.81
1.8 4.93
1.9 5.01
2.0 5.01

 

Thanks

The avc-r doesn't require a map input so I dont think it's that. I'll check it with the voltmeter and see what the story is...