Piers300

Hi Lee. I believe that all speed sensors have a magnetic tip. The ones I use at work on large Diesel engines will pick up swarf particles, caused by the starter motor ring gear engagement. When it happens, the ac voltage coming out of the magnetic pick-up is very badly effected and the speed control system goes a bit haywire. Piers

Lee. Yes, it seems that we have the same issue. If I start it by squinting fuel in the T/B's, away it goes and it runs smoothly and goes well. Last week, I went to the local 7 Club Meeting. I had to squirt fuel in to start the car at home and I had a 40 minute run to the meeting. So after eating, we came out and it started first time, so I felt confident it would start when time to leave. Another 45 minutes of chat and time to go and of course it would not start, much to everyone's amazement. A quick squirt and away it went and ran fine. The only thing I have not replaced is the ECU and the TPS and then there is the wiring.. Plus I do have he original in tank pump, but this was checked when serviced and was I think 3.5 bar at the fuel rail. Lee. I will keep you in the loop on all developments. Piers

Unfortunately, the car would not start today, but did fire once or twice on the first attempt. Since then and numerous attempts - nothing, so we are not there yet. Incredibly frustrating and I have not squirted fuel into the t/b's and I am sure it will then start. Only thing that has not been replaced is the TPS, but when connected to the laptop, it seemed to be working to specification. I did take out the new crankshaft sensor and put the old one back in, but no difference so the new one went back in. Piers

Lee. The crankshaft sensor is Euro Car Parts no: 419750061 and had a list price of £72.26 and I paid £23.49. Description is crankshaft sensor Rover/MG 2. I am not quite sure why the discount but probably a cash sale. Piers

Lee The replacement sensor from Eurospares was £23 and is pretty easy to replace. It just bolts into place and has a plug and socket arrangement .I will get you the part number tomorrow as sitting in bed reading posts at the moment. Revilla when Arnie connected to the ECU and we cranked for the first time, the software displayed some very strange readings from the sensor, no doubt caused by the swarf on the tip of the sensor. As I understand it, the ECU would not switch on the fuel with this incorrect signal. I am no expert in this at all so it is from my memory from talking to Arnie. By squirting fuel into the t/b's , the engine starts and I must assume that the voltage from the sensor gets better and the ECU then gives fuel. John the wiring for the flywheel sensor is a fair distance from the new HT leads, as it is down by the clutch cable. However the HT lead from the coil runs quite close. I will check it tomorrow when I do some start tests Piers

I am told by Arnie, that the ECU gets it signal from the crank sensor and then the ECU gives the engine some fuel. As the signal from the crank sensor was rubbish due to the swarf on the tip, the ECU was not giving the RB's any fuel, hence it would start if you squirted some in and the speed increased which was sufficient for the system to run and get a better voltage from the sensor. Piers

Well, I think we have a result. Arnie Webb very kindly came over to my house on Saturday. He said the first thing that needed doing was to install the RS232 cable into the ECU, as without it, we were in the dark to what was going on. He already suspected one item and this would show up on the laptop once connected. So once the cable was installed and connected to his laptop, we cranked the engine and Arnie noticed that the signal from the flywheel sensor was very strange and all over the place. We removed the flywheel sensor, something I have not replaced and found a bit of swarf on the magnetic tip. This was what Arnie suspected from the start. As the sensor looked rather tatty, a quick trip into Canterbury where we got a new unit. When installed, the car started first press of the button and has continued to do so since yesterday. The signal from the new sensor was as it should be on the laptop. So it looks to have been the crankshaft sensor that was causing the problems and some regular starts from cold should prove we have cracked the problem. A very big thank you to Arnie Webb for his time to sort my problems out. Piers ​

I had a Super Sprint from 1985 to 2010. I recall issues of the in tank sealant being sucked into the fuel line and blocking it. The way to clear it, is disconnect fuel line at the tank and carbs and either use an air line or foot pump to pressurise the fuel line. What flew out of mine way interesting. Piers

Hi John The cable is being installed on Saturday, so watch this space. Piers

Your questions Yes, I have tried cold starting with the Pipercross filter removed - no difference. Yes, I keep my foot off the throttle - always have, but once it starts then the throttle can be used. when it starts it idles at around 1000 rpm No, the wiring loom does not have a serial port that I can find and I don't have any comms cable or laptop with the old XP. Thanks all Piers

Just got back from the local East Kent 7 meeting, where true to form, the car failed to start when ready to leave. However a quick squirt of petrol into the T/B's and it started. I went prepared for this to happen. i will answer all questions tomorrow. Thank you everyone for your continued help. Piers

Unfortunately, the car would not start this evening, so I am back to where I was before. It still starts with a squirt of fuel. Piers

Lee - I just did the in-line filter that is located behind the drivers seat. I did not know there was another one, Where is it ? Piers

Paul - When the car was picked up as a non runner, by the company who serviced it, they had ordered in a new in-tank fuel pump, because they thought it was either the pump or the relay module, which was replaced during the 6000 mile service. They tested the fuel pressure and said it was good. The car is a standard 2004 R300 with a locked MBE 72908 ECU and standard injectors. The air is taken from within the engine bay, via a Pipercross filter. I cleaned and washed the filter today, as I have a spare. I was going to fit it and I thought it was new, but it turned out to be dirty, but still in the CC packing. It came with the car when I bought it six years ago and because it was in the packing, I never really looked at it. I've got the foam filter cleaner and oiler left over from motor cycle Trials days, when you cleaned the bikes filter after virtually every trial. Piers

Jonathan. The volts on start up with the old battery was 10.2. I have not measured the new battery yet. Piers

John. Yes the old and new battery are on a conditioner when in the garage. When I took the old battery out, I measured with a certified Fluke 87 meter and it was 13 volts. The car had been running before hand hence the voltage but it is 6 plus years old, so that is pretty good. However the new battery cranks the engine faster. Piers

This morning, the car started on the second push of the start button and settled down into a smooth idle. I have to admit to being highly relieved and delighted at the same time. Piers

Well after a rather good weekend of Kent County Show yesterday, Wimbledon and F1 this afternoon, plus quite a few hours in the garage I will bring you up to date, I replaced the battery with a new Banner even though the old one is six plus years old and reading 13 volts when removed from the car. i then set about the t/b's and tried to adjust the opening to 1mm on each barrel. I then checked the resistance of the TPS and got a reading smack on what it is meant to be. I then started the car having to use the squirt of fuel in each barrel and using the synchroniser, checked the air flow and that was also spot on. Finally, I changed the in line fuel filter and what a faff that was. I got it done and I started the car. It was a bit rough to start with and then it settled down. I then left it to cool down, watched the F1 and took the dog for a walk. When it had really cooled, it started first turn of the key. I have to say I was mighty relieved, but the real test will be tomorrow morning. Piers

Lee Thanks for the link on the TPS. I hope to get some time in the garage tomorrow or Sunday. Unfortunately, mowing comes first and then teak oiling the garden tables and chairs. I have to fit the new battery, fuel filter, check the TPS and check the connection in the multipin plug below the t/b's. Thanks again Piers

A new Banner battery and fuel filter arrived today and both will be fitted over the weekend. If these don't crack the problem, the final thing is checking the TPS resistance. Piers

Dave J. I just tried disconnecting the air temp and water temp sensors in turn and no difference. The next thing is to do the TPS resistance check and check the balance. That will have to wait till Friday. Thank you everyone for responses. Piers

Steve, I am in Selsey for the weekend, but not in the 7, otherwise I would have joined you. Piers

Hi Lee Thanks for the advice. I will try and find your other threads and have a read. I have never tried to balance the RBTB's or adjust the voltage of the TPS before, so will need to do some reading and a phone call might be very useful next week. One thing I do have left over from my old Super Sprint with twin 40 DCOE's is an air flow meter, which looks like it will come in handy. Piers

Thanks everyone for your input, so will give it a go at the weekend. Piers

Just tried removing the filler cap and no whoosh. I tried starting and it cranks but does not fire at all. Piers