The car was put into storage in 2016. Note that it was running perfect at the time. I drained the fuel, put Sta-Bil in 2 gal and ran the engine. I pulled the plugs and sprayed the cylinder with fogging oil. The car had an ez life as the owner was in his 70's and only did track days and always took it ez. I do not know the engine/chassis hours but my guess is between 50 and 100. The engine is an injected/dry sump/1500 with original seals in place.
Prior to start up, I replaced the fuel cell and fuel pump (Walbro GSS242), all fluids and filters, plugs (CR9EB), and the battery (SBS30). I had the injectors cleaned and tested and they are fine (the worst was only 6% off before cleaning). Compression is 225-230 on all cylinders. Fuel pressure is a bit high at 3.5 bar. I spun it over without plugs and got oil pressure. When I tried to start it, it was a no go. I tried several times and with some throttle, I got it running but it would not idle. I increased the idle and with a warm engine, it would start and idle. I synched the injectors at about 6-7 on the synchrometer at idle. It got hot pretty quick while I was balancing the injectors which were all close to start with. Next day, it won't start without some throttle and wouldn't idle until warmed up. I had to play with the idle adjustment to get a nice idle. This time, I watched the clock and it was 100C on the gauge (confirmed by pyrometer) in about 8 minutes with an ambient of about 92deg (Houston). The electric water pump feels like it was running and it feels like it is flowing through the water tubes. This seems way quicker to hot than this car was, or my 2 previous Radicals. It's got the MBE 992 rev B, #34250, dated 02/02/06.
Questions: This car used to start and idle with no throttle like a normal FI car? What would change or what sensor should I change to try a fix? Could the .5 bar high fuel pressure be causing the problems with starting and idle? Can I get any data out of the MBE, ie throttle position sensor reading? What pigtail or plug does it take to get data? What about the quick to temp? It has the hip mounted rads. Any ideas? I have read most of the MBE posts on the forum and it seems that a lot of them are swapped out with something better. That's beyond something that I want to try and as noted, it ran fine before storage.
I appreciate any of your thoughts. Don
I have had a similar experience with one of my cars. Ran very rough and required extra throttle, but eventually died. It turned out to be weak batteries. After replacing both, car ran perfectly.
I don't know what this effects; perhaps the ECU or fuel system does not operate well under low voltage.
@davidf Thanks for your consideration of my issue. The on board battery is a new SBS30 and I use an Optima as a booster battery when starting. I wanted to check the alternator so I checked the voltage while the engine was running and it was about 12.7 volts. Seems that it was about 12.2 volts with the engine off but the master on which runs the water pump and fuel pump.
I don't have experience with gen 1&2 cars, so I cannot answer your questions about how to get data and what wire harness you need. For my cars, I have a data cable that plugs into the dash. I downloaded software from Radical which I installed on my laptop PC. PTMon is the application that shows the throttle position. For older data loggers, you might find some help here, AiM, or from Radical.
I have found that the most common source of idle issues are caused by:
1) faulty TPS or TPS not set correctly
2) weak battery
3) faulty coil wire(s)
I would not suspect high fuel pressure to be the cause, but you should adjust your regulator to 3 bar and do a TPS reset. In my experience, whenever I have balanced the throttle bodies and adjusted the TPS per the guidelines, the idle always comes to where it should -- around 1500 to 1600 with the TPS set to 4.0.
@speedstarincdjb, I agree with David, that sounds like the correct next step. I would also check the throttle body boots to see if they have cracked and are leaking. I would also check for any other intake leaks. Have you tried starting it without the air filter? Sometimes the air filters get gummed up and act like a choke. It is also worth checking the spark plug wires to make sure the spark is getting in the right place at the right time. Is it possible that the spark plug wires could have been put back in an incorrect order when changing the spark plugs? Don't ask me how I know to check that one...
I would also put more fresh fuel in the tank, perhaps the Stabul is causing issues?
I would also check the throttle body boots to see if they have cracked and are leaking.
Good idea. When checking these, you should remove each one from the thottle bodies, hold up in good light (e.g. sunlight), and gently bend the rubbers to check for cracks on the inside and outside.
@davidf ... thankyou for your suggestions. I do not have any way to check the throttle position sensor; however, I have not changed it since it ran great before putting the car into storage. The plug wires are Magnecore and were replacements from the originals. It is a good idea to ohm them all out to make sure that they are not defective.
@charleyhradicalsportscarregistry-com .. the air filter assembly is removed so that I have access to adjust the idle and synch the throttles. I marked the plug wires and they are on correctly. The engine management system on this series 1 car appears to be very basic. The only sensors on the engine (that I can find) are throttle position, air temp in the air box, and water temp. This is also wierd ... I have access to the fuel pump leads. When I turn the master on, the water pump runs and the f/p runs. It is making full pressure because I measured it. When I turn the ignition on, I hear the pump run up and then a click and it's the constant running like with the ignition off. I disconnected the f/p and when I turn the ignition on, the "run up" sound does not happen. Seems like the pump should be on or off, not on and more on! it's just a normal 12V constant speed (I think) fuel pump.
I ran it again today and same situation ... it will start but it's the idle is too low to keep running. If I ad throttle, it will respond and after it warms up, it will idle normally. BUT ... it gets hot (100C) very quickly ... like in less than 10 min of running. Would you think this is normal? The pump is running but no way to know if it's running the right speed.
I will inspect all of the throttle body boots but since it runs normally after warm up, don't think that's the issue. thanks for your council. Regards, Don
@charleyhradicalsportscarregistry-com ... fuel is fresh 110L race gas in a new fuel cell. Don
@charleyhradicalsportscarregistry-com ... fuel is fresh 110L race gas in a new fuel cell. Don
That made me think of something else to check. It is worth checking the fuel filter because sometimes there can be some fuel cell foam scraps in new fuel cells that can clog the filter. It is a bit of a long shot, but worth checking.
@charleyhradicalsportscarregistry-com .. thank you. I checked the fuel filter and it was perfectly clean. I have taken down the number and will replace it as soon as i can find one ... or replace it with a new Kinsler filter. Don
I ran it again today and same situation ... it will start but it's the idle is too low to keep running. If I ad throttle, it will respond and after it warms up, it will idle normally. BUT ... it gets hot (100C) very quickly ... like in less than 10 min of running. Would you think this is normal? The pump is running but no way to know if it's running the right speed.
I am servicing my car today and I timed the warm-up from cold start. 86°F outside temperature. It took 13 minutes for the oil temperature to reach 50C, and the water temperature never exceeded 90C. With the fan on, water temp drops to 88C. 1500 rpm idle.
Hi Don (@speedstarincdjb), A friend of mine at Radical read your post and texted me the process for checking / setting the Throttle Position Sensor (TPS) on cars with MBE ECUs. He said that you should back probe the TPS connecter on the center red wire and adjust the TPS to read between .19 to .21 volts at idle. To back probe the connector insert a thin (positive) multimeter probe into the back of the sure seal connector and put the black probe on a chassis ground. I
I am going to post this in the DYI section also so others can find it in the future. If you have a chance can you take some pictures when you check your car and post them over there?
@charleyhradicalsportscarregistry-com Thank you and thanks to Radical. I am away for a week but will be right on this when I get back and take photos. Don
@davidf ... thanks for the data. No cooling fan on my car; just the circulating pump. Still, yours, runs cooler with the fan off. I'm going to pull the pump and make sure it's moving a good bit of water. I can hear/feel it pumping so I know that it works but not if it is moving a lot of water of a little. Don
