Hi All,

I've recently run into a hesitation/misfiring issue with my 7. The car has recently had a Microtech LT10c with X4 box and Bosch coils (Downgraded from Megasquirt 2…Sad i know) installed about a month ago and had a base dyno tuned for 9 psi.

The car had been running well in the first three weeks and it started showing symptoms of the hesitation/misfire. Here is a quick summary of the symptoms experienced when the problem started happening -

- When problem occurred I discovered a huge vacuum leak on one of the block off plates on the LIM. May have been poorly sealed with flange sealer and is a coincidence or caused by this problem, not sure. Have resolved this.

- The car is now quite difficult to start. Takes about 5 seconds of cranking before motor starts catching. When it starts catching, it starts coughing and doesn't start straight away. Usually requires an additional 3 seconds of cranking and some accelerator pedal and fires up

- Once started the motor is start and warming up, it idles smoothly at around 1000-1100 rpm.

- Once warmed up, free revving the engine up to 1500rpm and holding causes the motor to sound like it's running on 1 rotor and backfire. This can happening anywhere between about 1500 - 3500 rpm.

- Initial low load driving of the car causes the motor to sound like it's running on 1 rotor, backfires and has a lack of power in the 1500 - 3500 range at about 20 - 25% throttle.

- Motor enters boost fine at around 4000rpm with no misfiring/hesitation but power feels slightly decreased.

- Motor does not want to idle on it's own after driving it. Have to keep touching the accelerator pedal to prevent motor from stalling out.

I currently have a LC-1 installed in my car, but unfortunately is not working (second failed LC-1 controller), so i'm unable to verify AFRs when the problem occurs.

I'm not sure if the issue may be related - Since the issue happened, the Microtech would not use the Idle map anymore. Even though the TPS is properly calibrated and shows 0% when off the pedal.

I've really run of ideas on troubleshooting this issue. Would really appreciate any input provided.

The following lists the troubleshooting i've completed so far:

- Fixed massive vacuum leak by LIM block off plate
- Removed UIM and checked for additional vacuum leaks - non found
- Checked condition of injector clips making sure they are firmly seated
- Check condition of vacuum hose to map sensor on the Microtech ECU. Appears to be fine
- Placed Microtech ECU in test mode and verified spark each lead
- Pulled spark plugs (2000 Kms old) and inspected. Appears to have minor carbon build up/very dark colour. Replaced spark plugs with a new set of BUREQ9s all round anyway.
- Pulled fuel pump and inspected filter sock - Appears to be clean
- Pulled fuel filter and inspected - Appears to be clean
- Cleaned grounds and added additional grounds from the battery to the chassis, chassis to engine block

My current setup is:

- 13b extend port 3mm seals rebuilt 8000 Kms on the rebuild

- Single Aeromotive 340 pump, Aeromotive Reg set at 40-41psi open air

- 850cc primary, 1680 cc secondaries
- Microtech LT10c with x4 box and Bosch coils

- MasterPower t-64

- Tial 44mm wastegate

- Coolingmist CMGS water injection (380cc pre turbo, 760cc post turbo nozzles) - Flow starts at 5Psi, full flow by 20PSI
-PWR Barrel Water to Air intercooler

Microtech Map -

idle Screen 1

30" 0.76
25" 1.10
20" 1.10
15" 1.24
10" 1.43
05" 2.19
00" 3.05
Aux 02psi 4.95
Aux 04 - 20 psi 4.95

Load

30" .. 0.90
25" .. 0.95
20" .. 1.10
15" .. 1.29
10" .. 1.76
05" .. 2.57
00" .. 2.76
02psi .. 2.81
04psi .. 3.24
06psi .. 4.19
08psi .. 4.81
10psi .. 5.57
14psi .. 6.90
16psi .. 7.76
18psi .. 8.43
20psi .. 8.43

RPMwot

500 .. +00%
1000 .. +00%
1500 .. +03%
2000 .. +00%
2500 .. +00%
3000 .. +00%
3500 - 9000 .. +00%

RPMcrs

0500 .. +00%
1000 .. +00%
1500 .. -03%
2000 - +00%
2500 -9000 .. +00%

Pump

Pump1 Amt 10
Pump1 Pulse +02
Pump 1 Trig + 14
Pump Stop 00"
Pump 2 start 2000
Pump2 AMT +30%
Pump 2 TIME +10
Pump 2 TRIG + 16
Pump 2 STOP 00"
Pump 1 Adv 05+
Pump 2 Adv 05+
Pump Dwell 5.00
Pump Timers NO
Pump 1 Sync NO
Pump Spare +8
Pump Cold 00

Water

124 C .. +00%
99 C .. +00%
82 C .. +00%
68 C .. +04 %
60 C .. +10%
46 C .. +15%
38 C .. +20%
31 C .. +26 %
24 C .. +32%
18 C .. +39%
11 C .. +46%
05 C .. +49%
-01 C .. +55%
-09 C .. +60%
-17 C .. +70%
-25 C .. +00%

air_t
-25 C .. +00%
-17 C .. +08%
-09 C .. +06%
-01 C .. +05%
05 C .. +05%
11 C .. +03%
18 C .. +02%
24 C .. +00%
31 C .. +00%
38 C .. +00%
46 C .. +00%
60 C .. +00%
68 C .. +00%
82 C .. +00%
99 C .. +00%
124 C .. +00%

Crank

-25 C .. 72%
-17 C .. 72%
-09 C .. 72%
-01 C .. 67%
05 C .. 62%
11 C .. 57%
18 C .. 50%
24 C .. 41%
31 C .. 31%
38 C .. 26%
46 C .. 20%
60 C .. 15%
68 C .. 05%
82 C .. 00%
99 C .. 00%
124 C .. 00%

t*rpm

idle .. 00
1000 .. +10
1500 .. +15
2000 .. +20
2500 .. +25
3000 .. +25
3500 .. +25
4000 - 9000 .. +25

t*map

idle .. 00
25"Hg .. +05
20"Hg .. +04
15"Hg .. +03
10"Hg .. +02
05"Hg .. +00
00"Hg .. +00
02psi .. -02
04psi .. -04
06psi .. -06
08psi .. -08
10psi .. -11
14psi .. -15
16psi .. -17
18psi .. -18
20psi .. -19

t air

0 C - 124C .. +00%

t gap

0500 .. 15
1000 .. 15
1500 .. 15
2000 .. 15
2500 .. 12
3000 .. 10
3500 .. 10
4000 .. 9000 10

t*inj

0500 .. 150
1000 .. 150
1500 .. 180
2000 .. 180
2500 .. 180
3000 .. 180
3500 .. 180
4000 .. 180
4500 .. 210
5000 .. 210
5500 .. 210
6000 .. 240
6500 .. 240
7000 .. 270
8000 .. 270
9000 .. 270

t*wat

-25 C - 124 C .. +00

Option

Opt MIXtrim - 20%
Opt TPScal - 30%
Opt TIMtrm - 00
Opt Static - 00
Opt TIM MAX 30
Opt RPM Wot 05"
Opt rpmCRS 12"
Opt Af_StE +10
Opt IGNlim OFF
Opt REVCut 8560
Opt BOOSTCut OFF
Opt REVstg 2120
Opt MAPstg 02"
Opt %stage 99
Decel 25"
Dwell 5.00

Maps = Normal
Config +04 Cyl/R
Firing SEQUENTIAL
LOAD = MAP Sensor
DWELL = Time base
Input Trig +POS
Spark Trig - IGBT
Timing check OFF
Rpm_ON 2500 Log
Map_ON 02psi Log
Sample +00 Log
Spare +00 Log
SHIFT 7500 Dash
WATER 99 C Dash
Air_T 40 C Dash
BOOST OFF Dash

Cheers
Grant

 

The car sounds like it's starving for fuel, if it has a delay when cranking give it more fuel. The big vacumn leak changes things and the dwell is set to high can burn the x4 box. Change it from 5.00 dwell to 3.5!

 

Thanks for you response. I'll play around with the Crank maps and see it improves. Will also drop the Dwell time down.

Cheers

 

Issue resolved - Pulled the injectors and flow tests showed 3 out of 4 injectors flowing miserably.. Re-installed cleaned injectors and car performs better than ever.

 

Yeah dirty injectors will give you a headache, I'm glad you got if figured out!

 

mixtrim -20 % whats the go with that . you need mixtrim to be set at zero..