DirtyDeeds Posted May 23, 2018 Share Posted May 23, 2018 hey guys, my mj is running super rich at idle, it started doing it about a month ago and it levels out a bit at driving speeds nut stil rich. Its so rich its blowing out thick fuel smoke and well my cat don't like it lol. I'm thinking it might be staying In closed loop for some reason. I have my coolent set up to run really cool to stay cool on the beach but I'm not sure that is it because its just started and nothing has changed with my cooling set up in well over a year. Any ideas? Link to comment Share on other sites More sharing options...
Pete M Posted May 23, 2018 Share Posted May 23, 2018 Quote I have my coolant set up to run really cool to stay cool I don't understand what this means. Link to comment Share on other sites More sharing options...
DirtyDeeds Posted May 23, 2018 Author Share Posted May 23, 2018 25 minutes ago, Pete M said: I don't understand what this means. well because I live in south Texas and in the summer it easily ranges from 95-113 degrees I tuned my cooling system ro run cool to prevent overheating. I spend alot of time on the beach and when your driving 15-20mph in soft sand at 2+k In the same direction the wind is going it ends up being like there is no air going across your radiator. So I removed my thermostat and have 3 electric fans on top of my clutch fan but I only use the electric fans when it is necessary. Normal idle and driving it stays around 78-86 Celsius but on the beach its right around operating temp Link to comment Share on other sites More sharing options...
Pete M Posted May 23, 2018 Share Posted May 23, 2018 well, lets start with the basics then. put a 195* thermostat back in. removing it does nothing to prevent overheating. its sole purpose is to keep closed to help bring the engine up to operating temp as quickly as possible so you can burn the fuel at max efficiency. after that, it opens up and becomes irrelevant. edit: corrected my temp Link to comment Share on other sites More sharing options...
DirtyDeeds Posted May 24, 2018 Author Share Posted May 24, 2018 14 hours ago, Pete M said: well, lets start with the basics then. put a 180* thermostat back in. removing it does nothing to prevent overheating. its sole purpose is to keep closed to help bring the engine up to operating temp as quickly as possible so you can burn the fuel at max efficiency. after that, it opens up and becomes irrelevant. well it does act as restriction to flow. I removed it because the extra electric fans and new radiator wasn't enough driving with the wind on the beach, all other driving it was just fine. id rather not have it over heat 50 miles from civilization with the tide coming in. But like I said this just started a moth ago and I've been running it like this for over a year. It wasn't even doing this over the winter where the temp never got above 110 degrees Fahrenheit. Is there anything else that could cause it? Link to comment Share on other sites More sharing options...
dvitha Posted May 24, 2018 Share Posted May 24, 2018 I think at first is asking to trick the coolant sensor to thinking it is higher than it is. If you know your electric, you can in theory put a fuel resistors before the plug of the coolant sensor. This would allow fool the ecu a bit. However once you do hit 205 or above it would read super hot. All my jeep run 2 bottles of hyperlube super coolant with 70 water / 30 coolant mix in North Texas. During winter they run right at 180 or 82°C all the time with no e-fans blowing at all. During summer 90% of the time 1 fan comes on and runs 195 to 205. I have yet to see 210 even on days it is 105 or above. So if this just started a month ago, how it the condition of your coolant? nice and clean? You did not say if you had a thermostat or no. I would check to see if it is frozen open. This would cause it to run very cool. Also when the engine is running to rich this can cause a cooling effect. a bad or not working o2 heater will cause rich running. Also a bad temp sensor will cause rich running. A leaky injector or over pressure fuel line would cause running rich as well. Link to comment Share on other sites More sharing options...
Pete M Posted May 24, 2018 Share Posted May 24, 2018 it isn't enough of a restriction to matter. there is something else wrong if the engine can't stay at around 210* under all conditions. how old is the radiator? water pump? do you have an intact fan shroud for the mech fan? items that can cause a sudden rich situation include: bad coolant temp sensor, bad O2 sensor, or an injector that has failed in some manner and is spewing gas in an uncontrolled manner. Link to comment Share on other sites More sharing options...
Eagle Posted May 24, 2018 Share Posted May 24, 2018 18 hours ago, DirtyDeeds said: well because I live in south Texas and in the summer it easily ranges from 95-113 degrees I tuned my cooling system ro run cool to prevent overheating. I spend alot of time on the beach and when your driving 15-20mph in soft sand at 2+k In the same direction the wind is going it ends up being like there is no air going across your radiator. So I removed my thermostat and have 3 electric fans on top of my clutch fan but I only use the electric fans when it is necessary. Normal idle and driving it stays around 78-86 Celsius but on the beach its right around operating temp I know why you did what you did, but it is probably the cause of your problem. The thermostat is there to keep the temperature UP, not down. Factry thermostat is 195 degrees, the absolute lowest you can (not "should") run is 180. The system needs to get up to something like 165 or 170 degrees to switch into closed loop mode. A 165 degree thermostat won't do it, and I'm pretty certain that NO thermostat certainly can't do it. Even in sand, you want to be able to keep the temperature from going higher than 210 or so, but you shouldn't be trying to keep it below 195. Keep your three fans but put a 195 degree thermostat back in and see what happens. (And besure to get a t-stat with the are relief bleeder, and burp the system.) Link to comment Share on other sites More sharing options...
Ωhm Posted May 24, 2018 Share Posted May 24, 2018 Engine running at 'normal operating temperature' includes thermostat (195°) for stable temperature and proper engine combustion. Reinstall it. Think of looking into a REM for your vehicle, before loading the parts cannon. Don't forget about cruiser54 tips for poor ground circuits. RENIX ENGINE MONITOR (REM) Link to comment Share on other sites More sharing options...
Pete M Posted May 24, 2018 Share Posted May 24, 2018 corrected my thermostat temp in my prior post. I meant 195. Link to comment Share on other sites More sharing options...
cruiser54 Posted May 24, 2018 Share Posted May 24, 2018 Check the vacuum line from the throttle body to MAP sensor on the firewall. And do Tips 1 through 5 at www.cruiser54.com while you're at it. Link to comment Share on other sites More sharing options...
87MJTIM Posted May 25, 2018 Share Posted May 25, 2018 have you checked to see if an injector is stuck open? That would be feeding too much fuel to the engine. Link to comment Share on other sites More sharing options...
DirtyComanche Posted May 25, 2018 Share Posted May 25, 2018 Xwhatever on putting a thermostat back in. It's probably only part of the problem though. Link to comment Share on other sites More sharing options...
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