CamH Posted April 23, 2009 Author Share Posted April 23, 2009 I am going to check the fuel pressure after work today. It is really starting to make sense to me that I am getting too much fuel pressure. I have a fuel pump feeding a surge tank in the front of the car and a 255LPH fuel pump feeding to my fuel rail. The fuel rail returns to the surge tank, and the surge tank returns to the gas tank through the regular return line. I think the regular return line may not be enough for the fuel setup that I have. This is going to be the first thing that I look into. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted April 23, 2009 Share Posted April 23, 2009 Pressure should be in the 30's. Look for any changes in megatune with anything mentioned, when it's running. Quote Link to comment Share on other sites More sharing options...
CamH Posted April 25, 2009 Author Share Posted April 25, 2009 Alright, guys, just got back from messing with the car. I changed from using the old fuel return line from the small carb one to the breather one on the other side of the engine bay. This helped IMMENSELY. The car will now sit and run fine on its own for an extended period of time. I actually tried driving it today. I also turned off my barometric correction and that helped as well. Unfortunately, when I tried taking the car for a drive and datalogging, I ran out of gas. After putting another five gallons in the tank 15 minutes later, I could not get it to start properly. After waiting a good hour or so, I got the car to start and run again (roughly), so I took it back to my buddy's house where I keep the car and parked it, as it was not running well. So I didn't get any datalogs. As a side note, I am unsure if I may still have too much fuel pressure. The car is still running fairly rich. Nobody I know has a gauge for this. I am considering buying an inline fuel pressure regulator (with gauge) instead of running the factor L28ET one. Any thoughts or recommendations on this? I will probably not mess with the car tomorrow (go karting at Qualcomm woo hoo!). However, I would appreciate some more input as to what could be going wrong. I'd really like to start driving this car soon! Quote Link to comment Share on other sites More sharing options...
dexter72 Posted April 25, 2009 Share Posted April 25, 2009 Have you tried putting in lower numbers in your VE table yet?. I think your Wideband may be messed up from having the engine run so rich. Just try putting in lower numbers in the bins it idles at. If you go to low you will notice the engine idle lower and lower. If your atanding at the back of the car and your eyes are watering then the engine is running way too rich so yes, you need to lean out the fuel tables If you pull the vacuum line to the regulator check to see if there is fuel in that vacuum hose. If so the regulator is bad, so get another one. You can buy a cheap fuel pressure gauge from harbor freight if there is one in your area. About $15.00. Quote Link to comment Share on other sites More sharing options...
CamH Posted April 26, 2009 Author Share Posted April 26, 2009 Yep, the car definitely runs rich enough to make your eyes water when it is running. I know there is a harbor freight around here somewhere. I will make a trip there today and see about a fuel pressure gauge. One of the things I noticed about the really cheap ones online is that they only go up to 15PSI so they are likely for carbureted engines. Quote Link to comment Share on other sites More sharing options...
CamH Posted April 26, 2009 Author Share Posted April 26, 2009 Ugh, so I am messing with the car right now. I came over, started the car up (and it started immediately.) I started playing with some of the settings in MegaSquirt (mostly VE and Accel settings) and after about 20 minutes, when the car was warm, I decided to shut it off to go grab something to drink. The car won't restart! I'm totally lost on why I can't get it to start. I've taken the spark plugs out and cleaned them, switched the pulsewidths for warm up wizard to the same as the cold one (where it easily starts!) and I am getting nowhere. If I am going to drive this thing, I need it to start up warm and cold, not just cold! Any ideas, guys? I should note that the fuel rail does not feel hot, and I have run the fuel pumps without anything else on, so it shouldnt be putting hot fuel into the engine. Quote Link to comment Share on other sites More sharing options...
CamH Posted April 27, 2009 Author Share Posted April 27, 2009 Well I fixed a part of the hot start issue by switching the "Pulsewidth at 160" setting under the Warmup Wizard menu to 25. However, it still took it much longer to start up warm than it does when cold. Does it seem correct to have a higher number with that setting than the cold setting? Quote Link to comment Share on other sites More sharing options...
CamH Posted May 12, 2009 Author Share Posted May 12, 2009 Here is a recent datalog and MSQ file. I am still having problems with the acceleration settings. I still haven't tested the fuel pressure, but I ordered a nice pressure gauge and will be installing it as soon as it arrives so I can verify that I am running the correct fuel pressure. heh.zip Quote Link to comment Share on other sites More sharing options...
CamH Posted May 24, 2009 Author Share Posted May 24, 2009 Alright, guys, I just got back from messing around with the car. Someone on another forum pointed out that my MAP reading was way off and I had the vacuum line for the MAP sensor in the wrong location (bottom of the throttle body.) I relocated the MAP sensor and put the fuel pressure gauge on it. Nothing but trouble! According to my fuel pressure gauge, I've only got 1PSI of fuel pressure when the fuel pumps are running - even if I smash the return line. Could this be indicative of a bad fuel pump or a bad fuel pressure gauge? I'm not sure! I tried running the car like this and it would run for a few seconds and then die down and not start again for 20 or 30 minutes. Amazing! With the MAP sensor relocated, I've got like 80-90KPA during cranking. If the car starts, it goes down to 60KPA which is probably about right! Of course, the car won't run long... A side note: A few months back, I ran the fuel tank dry and the fuel pump was running for a few minutes dry. It got extremely hot and blew my fuse for the fuel pumps. Is there a chance that it would have been fine for a few months before blowing out all the way? Also, I don't think it has anything to do with getting a proper reading for the MAP because I disconnected the line for the MAP sensor so it would read about 100KPA the whole time and had the exact same symptoms. I'm not against buying a new fuel pump if it sounds correct that it is ruined but it seems odd that it would stop working the same day I fix the MAP. What do you guys think? Quote Link to comment Share on other sites More sharing options...
dexter72 Posted May 24, 2009 Share Posted May 24, 2009 I think you had two seperate issues. Check your fuel pressure before the filter also. or just remove the fuel filter and try to blow through it. You should be able to blow air through the filter with little effort. If you can't blow through it or have to use a lot of effort to blow through it, it's clogged. If you have filters before the pumps check those for clogging also. Otherwise you may be buying new pumps. Quote Link to comment Share on other sites More sharing options...
CamH Posted May 24, 2009 Author Share Posted May 24, 2009 I have a surge tank with a filter built in. No filter after the fuelpump which feeds into the fuel rail so I think we can rule that out because it had no problems drawing fuel from the surge tank. Quote Link to comment Share on other sites More sharing options...
CamH Posted May 27, 2009 Author Share Posted May 27, 2009 Update on the car! The walbro fuel pump was completely dead. I replaced it with a 65GPH high pressure Bosch inline pump. With the current tune, the car starts up almost immediately and revs up fairly smoothly. I was very happy with it. I datalogged a run up and down the street, and then drove the car to have the exhaust put on it. The exhaust is going to be a 3 inch with a straight through magnaflow in the middle and a resonator on the back. It will be done tomorrow. I'm attaching the datalog to this post for everyone's review and suggestions. It is using the MSQ file from my last post. Also, the first thing I said when I stepped on the gas was, "Holy ♥♥♥♥!" datalog200905261429.msl.zip Quote Link to comment Share on other sites More sharing options...
CamH Posted May 28, 2009 Author Share Posted May 28, 2009 Hey guys! I picked up from the exhaust shop today. Here are the results! It has a straight through Magnaflow muffler in the center of the exhaust, and a resonator on the back. It looks and sounds great! Quote Link to comment Share on other sites More sharing options...
e_racer1999 Posted May 30, 2009 Share Posted May 30, 2009 Glad to see it up and running! Also thanks for the help you've been giving me so far for MS. I am DEFINITELY going to be taking you up on your offer! Quote Link to comment Share on other sites More sharing options...
dexter72 Posted June 3, 2009 Share Posted June 3, 2009 Hey, Glad to read that you got it figured out and ir runs. ) So how do you like it so far?. Quote Link to comment Share on other sites More sharing options...
CamH Posted June 3, 2009 Author Share Posted June 3, 2009 I really like it so far. Thanks. The only problem is that I think I ruined the sensor for the LC1, because it can never give me a stable O2 reading, but I ordered a new one yesterday and it should be here by the end of the week. Quote Link to comment Share on other sites More sharing options...
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