RWInspired Posted December 6, 2010 Report Share Posted December 6, 2010 Hello guys! Got my 88 starion going recently and im having a problem with it leaning out. I have an upgraded fuel pump all filters are clean, in tank and in line. Fuel pressure is good at idle with stock fpr. injectors were cleaned years ago and just sat around. Running about 14 pounds of boost right now. all i have right now is a narrow band gauge for a lil piece of mind. I have the problem around 4000+ rpm at wot. i can watch the gauge go from several bars rich to an instant lean, and have a total loss of power. when i see, feel this i get off the gas. but if i get right back on it she goes right back to rich without a problem for the rest of the rev range. Don't have the cash to throw at it just yet, but id like to hear what u guys think. Quiz me for more hepfull info on this please. Link to comment Share on other sites More sharing options...
Indiana Posted December 7, 2010 Report Share Posted December 7, 2010 The combintion with the slightly larger turbo with that cam and the fact is you are out of fuel. A stock cam and you wouldn't be. You can get some fuel controller to add in more fuel and you might also want to get a different fuel pressure regulator. The regulator alone will work BUT you'll have issues with WOT in mid rpm range in any gear, it will just be too rich as the boost pressure has increased the fuel pressure so high past stock and the engine isn't needing all that fuel the ECU is dumping in until you reach higher rpms. The only way to deal with it without a fuel controller is to max out each gear and drive it hard every time. This is when those BPRxxx spark plugs foul out and misfire from the too rich condition in those mid rpm range pulls then they misfire at higher rpms. Changing to a BURxxx plug will at least allow you to pull through some of those gears and not misfire but you'll still be too rich. Link to comment Share on other sites More sharing options...
RWInspired Posted December 7, 2010 Author Report Share Posted December 7, 2010 Thank you for the responce. This only happens sometimes though. Could a cts cause this problem? I notice when she is warm at around 900rpm she doesn't seem to go into closed loop. Just sits at a steady rich cycle. if i give her just a coulpe hundred more rpms i see the afr bounce around like it should, right? I've read that when the cts goes bad that it can either throw too much fuel or not enough. I've got a maf-t to install one day. I just don't think this is a normal lean out condition, it almost seems like a fuel cut is going on. O, ive also reset the tps, isc several times. Link to comment Share on other sites More sharing options...
StarquestRescue Posted December 7, 2010 Report Share Posted December 7, 2010 (edited) What exhaust? What mas? ahp or accordion pipe? I have the problem around 4000+ rpm at wot This is typically the richest part of the power band and afr can dip into the high 9's causing a rich misfire typically described as a stutter. Car maintains speed or accelerates at a slower rate. If the ecu sees a high enough airflow signal at this point it will fuel cut. A complete lose of power for an instant, then comes back on. The solution is to modified the airflow signal with a maft or afc type fuel controller. Lean it out at this point in the power band. This is best done with a wide band. The stock or 1g mas, especially with an ahp, can give an erratic signal at high air flow that compounds the problems with the stock fuel system. A maft address that problem as well. I ran a stock accordion pipe for years and had few problems. When i put an ahp on the car i had the typical problems you and many others have described. Ahp's typical block of several sources of unentered air. So more air goes through the meter, which just throws even more fuel on the fire. Edited December 7, 2010 by StarquestRescue Link to comment Share on other sites More sharing options...
RWInspired Posted December 7, 2010 Author Report Share Posted December 7, 2010 Great info!!! I've got tep 2.5 dp, 2.5 intermediate with cat, stock back. Stock mas and acord pipe. I do agree that it seem's to have a rich missfire sometimes. What i dont understand then is why the mas see's the most air at around 4000 rpm causing it to fuel cut. Is this about the point when both injectors start to fire. Does the mas just trip out at this point? I would think that once the engine goes lean at whatever rpm it would continue on through the rest of the rpm range. i've never kept on the gas when this happens, so not sure if it comes back. But i do know that if let off for a split second then shes ok for the rest of the rev range. Either way i need to install my maft and get a wideband setup. Holding back cause i've had similar problems when everything was stock years ago. Just want the semi stock setup to work right, but I guess im past that point. Also since you bring up the ahp, what do you think about manual boost controlers that bleeds metered air? Thank you for the info thus far. Link to comment Share on other sites More sharing options...
RWInspired Posted December 7, 2010 Author Report Share Posted December 7, 2010 Just realized what you ment by the block offs on the ahp. I've removed the oil speration system and pluged the hole. Link to comment Share on other sites More sharing options...
Indiana Posted December 7, 2010 Report Share Posted December 7, 2010 (edited) That cam will cause your idle to be just about right or on the lean side compared to stock, its sucking in way more air than a stock cam does then about mid rpm range+ you'll be out of fuel say at 20psi. If it were a 294 cam with a stock primary injector there isn't enough fuel for it to idle you are up into the high teens-low 20s on your air fuel and it dies when you try and take off. You using stock valves or over size? OS valves its worse for a stock fuel system and injector sizes since the valves allow more flow. The CTS doesn't have anything to do with open or closed loop for a Starion, that's not true for other Mitsubishis though because they do control the open and closed loop and its around 140 degrees of the coolant that it happens. Its the 02 hot enough that cause that. You can use a heated 02 and on a cold day you'll see the air fuel start to sweep just after you take off driving so that the tip switch of the idle motor isn't closed which causes the loop to change and its not using the 02 while at idle or wide open throttle and your temperature gauge hasn't even moved off the bottom. Its part of how the fuel maps were made I guess, they needed the 02 correction and the CTS can't do crap for that so the CTS is only used like a choke, its for cold starts then as coolant heats up it fades down to doing nothing. You can drive one without a CTS you won't know it except for a cold day and you start up it might run a little lean or chug for a minute until you rev it up. http://www.b2600turbo.com/images/151.jpg http://www.b2600turbo.com/images/14-12.jpg http://www.b2600turbo.com/images/14-13.jpg http://www.b2600turbo.com/images/14-14.jpg http://www.b2600turbo.com/images/14-15.jpg Edited December 7, 2010 by Indiana Link to comment Share on other sites More sharing options...
RWInspired Posted December 9, 2010 Author Report Share Posted December 9, 2010 I'll have to sit down for a while and read through my manual to get myself familar with these systems again before i ask anymore questions. Thank you again for the info. Link to comment Share on other sites More sharing options...
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