What's going on? T2 ecu
Posted: Sat Aug 27, 2022 6:07 am
Please bear with me - this is a long story but thought it better to tell all...
I have a Porsche 914 I use for hillclimbing which now runs a T2 ecu with wasted spark. Injectors are Bosch 440, crank sensor/trigger is Hall effect 36-1 set-up from Dubshop in the USA, with 48mm throttle bodies from CB Performance.
Car ran fine after set-up on Rawspeed rolling road in Plymouth (Graham Rawlings is the south west's DTA expert!), starting at the turn of a key without touching throttle etc. A few weeks ago on a Thursday I drove up to Dartmoor to meet a friend – the car ran faultlessly. I left it until the following Tuesday when I decided to check it over ahead of a hillclimb event the following weekend. It suddenly became reluctant to start, turning over and over. When it did start, it issued a belch of black smoke out of the exhaust. I went to drive the car up the road, but it could barely get out of its own way. I suspected a failed TPS as the only way it reacted was with wide-open throttle – I guessed the TPS was telling the ECU it was on wide-open throttle regardless of throttle potion, hence the over-fuelling. After some checking and rechecking, came to the conclusion the TPS was working and the car started... Too late for the hillclimb, but at least it started. Then a couple of days later it wouldn't start unless I jumped it off my Golf and kept turning it over for an eternity. However, once started, it would restart for the rest of the day, albeit a bit sluggish turning over.
Thinking the slow cranking speed might be a problem, a replaced the starter motor with a high-torque geared unit, and the old Optima red top battery with a new Odyssey. The engine spun over but wouldn't start.
The ECU wouldn't always connect with my laptop so it was difficult to see what was going on at times. When it did connect, I tried checking the crank oscilloscope readout but it wouldn't gather information (see video). I checked the sensor was working with a multimeter and manually turning the engine. It read 0 – 5v – 0 etc, suggesting all OK.
As it didn't even cough, I visually checked the injectors by opening the throttle wide and looking down the throttle bodies while my wife cranked the engine on the starter. Nothing from the injectors, but plenty of fuel pressure. Hmmm.
I sent the ECU back to Alex to check and it came back with a clean bill of health, other than a software adjustment to solve the comms problem with my laptop. I've now fitted a new TPS and wanted to try using the test function on the DTA software to check the injectors, but gather this is not possible with the Beta software.
What I don't get is how it went from running perfectly OK to reluctant to start and then on to won't start at all, without any warning or changes to settings. This is all new to me – I had a 911 running Jenvey ITBs with a Megasquirt system which ran fine and required very little fettling once dialled in. This car is driving me mad – and is now stuck immobile outside my house while I try to solve a problem I don't understand with the telephone help of Graham who is 30 miles away.
I have a Porsche 914 I use for hillclimbing which now runs a T2 ecu with wasted spark. Injectors are Bosch 440, crank sensor/trigger is Hall effect 36-1 set-up from Dubshop in the USA, with 48mm throttle bodies from CB Performance.
Car ran fine after set-up on Rawspeed rolling road in Plymouth (Graham Rawlings is the south west's DTA expert!), starting at the turn of a key without touching throttle etc. A few weeks ago on a Thursday I drove up to Dartmoor to meet a friend – the car ran faultlessly. I left it until the following Tuesday when I decided to check it over ahead of a hillclimb event the following weekend. It suddenly became reluctant to start, turning over and over. When it did start, it issued a belch of black smoke out of the exhaust. I went to drive the car up the road, but it could barely get out of its own way. I suspected a failed TPS as the only way it reacted was with wide-open throttle – I guessed the TPS was telling the ECU it was on wide-open throttle regardless of throttle potion, hence the over-fuelling. After some checking and rechecking, came to the conclusion the TPS was working and the car started... Too late for the hillclimb, but at least it started. Then a couple of days later it wouldn't start unless I jumped it off my Golf and kept turning it over for an eternity. However, once started, it would restart for the rest of the day, albeit a bit sluggish turning over.
Thinking the slow cranking speed might be a problem, a replaced the starter motor with a high-torque geared unit, and the old Optima red top battery with a new Odyssey. The engine spun over but wouldn't start.
The ECU wouldn't always connect with my laptop so it was difficult to see what was going on at times. When it did connect, I tried checking the crank oscilloscope readout but it wouldn't gather information (see video). I checked the sensor was working with a multimeter and manually turning the engine. It read 0 – 5v – 0 etc, suggesting all OK.
As it didn't even cough, I visually checked the injectors by opening the throttle wide and looking down the throttle bodies while my wife cranked the engine on the starter. Nothing from the injectors, but plenty of fuel pressure. Hmmm.
I sent the ECU back to Alex to check and it came back with a clean bill of health, other than a software adjustment to solve the comms problem with my laptop. I've now fitted a new TPS and wanted to try using the test function on the DTA software to check the injectors, but gather this is not possible with the Beta software.
What I don't get is how it went from running perfectly OK to reluctant to start and then on to won't start at all, without any warning or changes to settings. This is all new to me – I had a 911 running Jenvey ITBs with a Megasquirt system which ran fine and required very little fettling once dialled in. This car is driving me mad – and is now stuck immobile outside my house while I try to solve a problem I don't understand with the telephone help of Graham who is 30 miles away.