mr2-digest Thursday, 11 January 1996 Volume 01 : Number 085 Redline Tranny Oil Re: mr2-digest V1 #84 Re: Oxy sensor Time to act is now! Re: low boost pressure RE: TEC issues Re: Turbo pressure sensor Timing belt Brakes Froze Outside dimensions of 91-95 MR2 RE: TEC issues Re: Gauges and rheostat Re: antenna in windshield Idle Problems, 4th Gear Boost, Turbo Sensing ---------------------------------------------------------------------- From: "Burns, James B." Date: Wed, 10 Jan 96 16:41:00 EST Subject: Redline Tranny Oil The RedLine 75W-90 has the friction modifiers for limited slip differentials, 75W-90NS does not. However, since the MR2 has a viscous-coupling rather than a clutch-type LSD, these friction modifiers are not necessary (at least this is what I was led to believe after extensively researching this subject). I think either one would work in your car. Mixing them might work fine, too, but I personally wouldn't do it. I put 75W-90 in my '94T with LSD and noticed no significant shifting difference. Well, maybe just a little better with a hot transmission (which is opposite of what I expected). FWIW, I plan to switch to 75W-90NS. I heard that it is more slippery which can allow the synchros to spin up quicker resulting in smoother shifting. The bottles of 75W-90 said "not for use in transmissions with copper-containing synchros". Do the bottles of 75W-90NS also say this? Brad Burns '94T ------------------------------ From: uunet!AZStarNet.com!sirota (David Sirota) Date: Wed, 10 Jan 1996 19:21:12 -0700 Subject: Re: mr2-digest V1 #84 >From: uunet!harvey.carol.net!bob (Robert Rogers) >Date: Wed, 10 Jan 1996 00:35:00 -0500 >Subject: rheostat and radio > >i like to drive with gauge lights dim because of my vision, but the >cassette-ETR display dims quicker than the gauges, so i can't tell what >frequency i'm tuned to! (i travel a lot at night and i "channel surf"). does >anyone have a not too complicated fix? maybe a resistor between the radio >input and the radio +12V (ground??) and a switch (day/night). >thanks for help. > >93NA 56,000 miles >bob rogers >bob@carol.net > Bob: I have complained about the same problem. The Toyota rep. found on the Toyota site says that is shouldn't be and to take it to the dealer. I bought my MR2 used and didn't get the security code. My local dealer says that they will R&R and send it in under warranty!! I'm going to ask that they correct the lighting problem at that time. ------------------------------ From: Itrat Khan Date: Wed, 10 Jan 1996 21:52:19 -0500 Subject: Re: Oxy sensor >>So, is this the oxy sensor? After work I'm gonna find some wire and see >>what the computer says. >Well, it sound like you're out of gas :-) >It also souns a lot like a broken timing belt :-( Actually, I've been having the same problem ever since I bought my '89 SC with 50,000 kms. It has nothing to do with gas, and since my car was only at 50k when I got it, I doubt the timing belt was worn. The one thing that might tie this to the oxy sensor is that the car would stall *only* if I started driving before the thermostat was at normal operating temperature. To recap, I would stop at a red light and when I pulled out of gear, the RPMs just dropped down to 0. I'd start the car, and it would drop down to 0. This would happen every time, so I'd start the car, keep my foot on the gas for a little while (about 20 seconds), keep my foot pressed on the brake real hard, and all would be normal. But sometimes when I would start moving while the car was "cold" (and it was trying to let more oxygen in), this problem would happen. Now I always let the car idle down to 800 RPMs before going anywhere and I've never seen this problem again. It's not a solution, but it might give someone an idea as to what's going on. I have a feeling this doesn't affect MKIIs. I can't remember if the original post was an MKI or not. If anyone figures out the problem, I'd love to hear it. Itrat '89 SC - -- . ~/.signature ------------------------------ From: "Murray, Matthew D." Date: Wed, 10 Jan 96 16:48:00 PST Subject: Time to act is now! I need to move these cars very quickly: MR2 turbo 1993, extra set of rims, T-Tops, ABS, Leather, P/S P/W P/L, nicely set up $13,900. Chevy Impala S/S, 1995, Leather, power options, CD, ABS $18,500. If I don't sell 'em in a week or so, I'm going to wholesale 'em. DON'T DELAY, NOWS YOUR CHANCE TO GET THEM CHEAP, I will bargin. Matt Murray Murray@gwns.groupw.wec.com MattMR2@aol.com h 203-454-4429 any day up to 2:00 pm w 203-965-6751 Tues to Fri 3:00 pm to 11:00 pm 1/10/96 16:46:00 ------------------------------ From: uunet!softwords.bc.ca!geoff (Geoff Seeley) Date: Wed, 10 Jan 96 21:39:14 Subject: Re: low boost pressure Dunno who originally posted the problem, but if you aren't getting full boost you might want to check the line from the wastegate actuator to the turbo pressure VSV, and the VSV itself... Why? Well, I just installed a boost controller in my '91 which involves routing the compressor side of the turbo to actuator line through a regulator motor. The second line from the VSV to actuator is plugged up. I am currently waiting for a FCD so the I've had the system off or in the test mode in which I should be getting stock boost levels. However, it seems that blocking off the second line to the VSV drops boost levels to a maximum of 0.40 bar or 5.8 psi. The effect of this is that the stock boost gauge will only reach the 3/4 mark (half pressure tick) This sort of sounds like what a few people have reported in way of symptoms for this problem so I thought I'd throw it out there is case this might be of use to someone... Geoff '91t, 161,000km ------------------------------ From: uunet!aol.com!AstonMrtn Date: Thu, 11 Jan 1996 02:39:05 -0500 Subject: RE: TEC issues >, you will need to cool this mass well below ambient air >temperature. There are thermoelectric devices that will cool >below 0C, but I don't know how much they cost or how pratical No problem there. TECs create a hot side and a cold side. If you want it even colder, just stack 2 TEC2 in series. > - The cooling ability of the thermoelectric devices will be >limited by how well you can heat sink them. Can you provide >enough coolingfor the devices themselves? And if powerful fans >are needed for these heatsinks how would that compare to using No problem here either. You don't need a lot of airflow to cool a heatsink, and the heatsink will be small enough that a relatively small fan will work. I've seen one for about $35 at a race car stor out here that's designed for mounting inline in a tube; I'll try that one. > - Finally, these devices will draw power from the engine via the >alternator. Do you get a net power gain from using them? Well, most of the time, the alternator is producing extra energy - take advantage of this! Only when under severe load (like night driving with all accessories turned on) are you pushing the limits of your alternator. So I have a feeling you won't even notice any difference there. It doesn't take much energy to drive an alternator, does it? - -Matt '91 White NA ------------------------------ From: uunet!sitka.triumf.ca!solu (Richard Soluk) Date: Wed, 10 Jan 1996 23:49:07 -0800 (PST) Subject: Re: Turbo pressure sensor > > > From: uunet!diane.csg.mot.com!mikep (Mike Pittelkow) > Date: Tue, 9 Jan 1996 16:19:41 -0600 > Subject: Turbo pressure sensor > > Has anyone tried disconnecting the turbo pressure sensor harness > from the sensor and driving to see if boost controlled fuel > cut still happens? Any other side effects (besides the dash > gauge not working)? > > Hey Cal, any ideas? > > - -mike > I suspect that disconnecting the sensor harness will give a sensor-not-working error, there is a engine trouble light code specifically for pressure sensor failure. Just unplugging the vacuum hose from the sensor will prevent the fuel cut, but the ECU then believes you are at 1 atmosphere pressure at all times and will tend to run too rich a fuel mixture under normal driving conditions. I did this for about 6 months and ended up with heavy carbon deposits (although I had also installed a BBR chip which may have made the problem worse). An HKS FCD is a better idea. ...Richard ------------------------------ From: uunet!arthor.cais.com!scott_maclean (Scott Maclean) Date: 11 Jan 1996 6:00 EST Subject: Timing belt Reply-To: scott_maclean@arthor.cais.com (Scott Maclean) I>>Ok, I've been following all this idling stuff with interest. They are seem I>>to be with warm idling. Well, this morning I jumped into my car (I haven't I>>used it for about 3 days) and started it and it was ok. I reversed around I>>the side of the house and stopped in the drive and took my foot off the I>>accelerator and it just dropped it's revs until it stalled. I found this I>>most interesting! ; ) (groan! ) .. anyway, I started it again and kept my I>>foot well away from the accelerator and it just did the same ... started and I>>then slowly dropped the revs and stalled. One time it almost managed to I>>catch itself and keep going. I>>So, is this the oxy sensor? After work I'm gonna find some wire and see I>>what the computer says. I>Well, it sound like you're out of gas :-) I>It also souns a lot like a broken timing belt :-( I>Oxy sensor is in the exhaust manifols, just before it connects to a flexer I>pipe. It looks like a big spark plug. It is directly under the car. I>But I severely doubt that what you're describing is the oxy sensor. It's definitely not a timing belt. I've had a timing belt break on me before (not in my MR2, it was in my awful '79 Mustang) and the engine just STOPS cold. It will not restart - obviously, because none of the valves will be operating anymore. Scott MacLean CASMEL-I Artificial Horizons BBS arthor@cais.com Aviation! (301) 417-9341 http://www.cais.com/arthor/www/index.html 300-33,600 bps V.FC/V.34+ * Free Access * Aviation Files * Usenet Newsgroups * CD-ROMs Online * ** Via PMail 2.3h Reg#658976 ------------------------------ From: DEMETRIUS LAMAR JOHNSON Date: Thu, 11 Jan 1996 10:27:42 -0500 (EST) Subject: Brakes Froze I own a 86 MR2, early this week we have had some frigid temperatures. I was over at my friends house and when i came back out the emergency brake felt limp. I tried to back out but the brakes were still stuck even though the brake light was off. I finally got the car to move but i could feel that the brakes were still partially applied. I drove the car anyways because it was to cold to walk home. The next morning i got in the car and everything was perfectly normal. I was just wondering if anyone can explain why this occured. Thanks ------------------------------ From: uunet!diane.csg.mot.com!mikep (Mike Pittelkow) Date: Thu, 11 Jan 1996 08:43:48 -0600 Subject: Outside dimensions of 91-95 MR2 Someone had asked, and I've now lost the email, how physically large the MR2 is. I looked it up, here are the numbers. Length, overall: 164.2 inches Width, overall: 66.9 inches Height, overall: 48.6 inches I don't know if the overall width is with or without the mirrors folded in. You'll obviously need some room to open the doors too :) Sorry to spam.... - -mike ------------------------------ From: uunet!aol.com!AstonMrtn Date: Thu, 11 Jan 1996 21:21:51 -0500 Subject: RE: TEC issues >of heatsinks and a 12V to 5V converter in to run the TEC, someone The TECs I'm looking at are rated at 15V max and 6A max. >on here should be able to help. > Calculation #1 How much cooling is desired, ie number of > > Calculation #2 How many TECs would be needed, including > Calculation #3 How much power, including alternator > Calculation #4 How much power would the engine gain >through this cooling (I think this number has been on here thanks >to Marc Summers). I'm a Mechanical Enginner, and was definitely planning on doing this before buying anything! I'll let you guys know how the numbers work out. I'll need to make a lot of approximations (like with the heatsink) but should be able to get a good idea... If someone could post the answer to #4, I'd really appreciate it. Also, please post the source - I'd be curious to see how those numbers were obtained. > - The air flow volume and speed are very high through the >intake, and air is not a good thermal conductor. Therefore you are >going to have to cool something roughly the size and design of a >conventional intercooler. To get a significant advantage over a >regular intercooler Sure, the air's moving a decent speed, but if you introduce turbulent flow, that speed will just help transfer heat faster (probably). Don't need something the size of a conventional intercooler, since the COOLING part of the system (the cold heat sink) - will be MUCH colder than the ambient air - therefore, less surface area needed for same cooling effect. - -Matt '91 White NA ------------------------------ From: uunet!illusion.magicno.com!marcus Date: Thu, 11 Jan 1996 12:25 MST Subject: Re: Gauges and rheostat Geoff.. One thought that comes to mind, that might be simpler to implement, is to re-wire the dash lighting. There's really no reason that the rheostat *has* to be on the ground side of the lights. I don't have a wiring diagram with me at the moment, but you might check if all the instrument lights are powered from the same source. If so, then it might be possible to run that source to the ground side of the rheostat and ground what used to be the +12V side of the lights. If there are multiple sources, then things get a bit trickier. One can always throw in a relay to help. If a circuit normally gets +12V switched from point A, then let point A power a relay that grounds a branch of the lights when energised. A transistor or OP-amp "inverter" is a cleaner way to go, but if it comes down to it, reversing the circuit may be an option... marcus hall '94 MR2T ------------------------------ From: uunet!illusion.magicno.com!marcus Date: Thu, 11 Jan 1996 12:20 MST Subject: Re: antenna in windshield >If the antenna in the windshield is a "diversity antenna", where did you find >this information? The owner's manual mentions that the antenna is a "diversity" system. What that is and how it works is from an article in Radio Electronics (now called Electronics Now) magazine. >... but where is the AM antenna? I believe that the AM radio runs off of the rear (main) antenna. In cars with a single antenna, the AM and FM both work off of the same antenna. marcus hall '94 MR2T ------------------------------ From: uunet!Rt66.com!cal (Cal Smith) Date: Thu, 11 Jan 96 01:44:34 MST Subject: Idle Problems, 4th Gear Boost, Turbo Sensing Sorry I've been off for a week or so (they were right--running your own company DOES take a little bit of time, after all...). This is a biggie, but stick with it--there's a little something for everybody here, especially a fun invite at the end. :-) Several folks have posted regarding cold or recently started engines stalling out at idle, some even with a foot on the gas. I doubt the oxygen sensor is to blame here (Good call to Mike S. and others). Look for vacuum leaks. The leaks that are "meaningless" (or, too small to feel) in a warm engine at 3000rpm can wreak havoc in an idling engine with 50 degree F. coolant. In fact, the factory manuals are very illuminating (...no pun to the Audio/Dash Lights thread ;-) ) on this subject: For virtually every symptom or malady relating to engine stumbling, stalling, etc. the first thing to do is _check the trouble codes_. If the ECU thinks something is wrong, let it do the hard work for you and figure out which part(s) is/are broken. If the ECU doesn't give you the 02-sensor code, #21, then the sensor is most likely OK. FWIW, the ECU will turn on the "Check Engine" light when it has something to tell you in the form of a trouble code. The most common problem you check for to quell the aforementioned symptoms is a _VACUUM LEAK_!!!!!!!! (if I could have used bold text, etc., I would have). I can not overstress how commonly vacuum leaks cause problems like those experienced lately by 'netters. These leaks are the first things you check for (other than the ECU codes) in almost every EFI/fuel-delivery/poor engine operating scenario, while the 02 sensor is nowhere on any factory engine-operation troubleshooting list (Even the ones that are 11 subsystem-checks long). Almost the only time to suspect a faulty 02 sensor is when the ECU tells you something is wrong with it (not that you should consider it infalliable; it just is a pretty doggone reliable piece of work compared to hose clamps, etc.). Here are the most common vacuum-leak causes: 1) Oil filler cap off, loose, or cracked (ever try to add oil while the engine is running? Amazing, isn't it). 2) Oil dipstick not fully seated or missing :-0 3) Hose connections (..."Gee, where does this extra hose go?," overheard after the installation of some hot new intake component. ;-) ) 4) Running a modified wastegate actuator where some boost pressure is bled off without using a check-valve (to stop the engine from sucking in extra air through the bleed hole under vacuum conditions. Ask me how I know. ;-) ). 5) PCV hose(s) 6) EGR System, where an EGR valve is stuck open. ...And now for something completely different... Once and for all: The crap that is in the intake hose between the air cleaner and the intercooler is from Positive Crankcase Ventilation (PCV). It is NOT from water getting through your HKS Super PowerFlow, etc. (gee, I inject H20 into _my_ engines to help increase the efficiency and make more power. :-) Yes, I know street-water in dirty, but it ain't PCV-dirty! Only PCV can get those tubes that cruddy). Twice and for all (NOTE: This section is largely IMHO. I am basing my opinion on a lot of time studying the Toyota tech manuals, talking to everyone who would listen, tearing apart/rebuilding/modifying my EFI system, and 12+ years of turbo experience): Getting lower boost is normal in near- or below-freezing temperatures is NORMAL. The ECU controls this as a way to protect the engine from overboost/overpressure conditions. Since air is more dense as the temperature drops, a turbo will cram more air (mass) into the engine when it's cold. Toyota is VERY conservative when it comes to high-performance engines (like a 'momma bear towards her cubs), and protection measures are all over the engine/ECU. The Fuel-Cut is set very low (about 225HP) to prevent crazy hot rodders from running an open wastegate and blowing the pistons through the muffler. Toyota figured the fuel-cut would be easy to trip if, say, your car came off the assembly line with an 11.8psi wastegate (upper allowable stock spec.) and you were hot-footing it on a cold-winter's night. Tripping the fuel-cut would only require about 10-12% more mass-flow--combine cold air with a stronger-than-average factory engine and you have a scared, confused, and P.O.'d Mr2 owner who is probably now walking to a pay phone for a tow. Plus, as soon as the car was turned back on, the fuel-cut would reinitialize and the symptom would dissappear, leaving the owner looking like an idiot while "Toothless Joe," the redneck garage mechanic, snickered at him/her for driving anything other than a 5.0 Mustang. Not exactly good P.R. for Toyota. So how, if you are Toyota, do you protect your engine from Gonzo Boys (tm) like most of us netters :-), without making us visit "Toothless Joe's Filling" (station)? They were pretty darn smart: The wastegate spring actually fully opens somewhere around 4-8psi. If you ran a reference tap off the turbo's compressor outlet into the wastegate actuator, you would see the wastegate consistently open at 4-8psi boost. Period. However, if you look closely at the wastegate-actuator you can see TWO pressure-taps on the canister. One to the turbo compressor-housing, while the other dissappears under the maze of intake plumbing. Where does it go? To the Turbocharging Pressure VSV (TP-VSV). The TP-VSV is an electronic valve (which opens when 10V+ to 14V+ is applied across its terminals) that, when open, diverts air from the wastegate actuator back upstream of the turbo compressor. Thus when open, the VSV bleeds off some of the pressure that otherwise would have opened the wastegate. Basically, the ECU sends the TP-VSV voltage when the temperature sensor in the mass-flow sensor says ambient temperatures are above freezing. The VSV will stay open as long as the voltage is present, and the actual wastegate actuation occurs at 7-11.8psi boost. When the temp drops below freezing, the ECU allows no voltage across the TP-VSV and the VSV closes, causing all no boost to be bled off. The wastegate "sees" all the boost in its true magnitude, and the wastegate opens at 4-7psi. One nice thing about the VSV is that it would tend to fail "safe;" no voltage across the terminals = lower boost. Toyota thinks of the details. Yes, take the why's and wherefore's of the above with salt--it's opinion. Until somebody comes along with a better theory though, I'm stickin' to it. :-) A VSV/aftermarket air-cleaner assembly note: As the reference temperature sensor is in the Mass-Flow sensor, it is common for heat-soak to allow brief periods of full boost. :-) Usually this occurs after coming to a stop for a while (red light, etc.) in freezing temperatures with a warmed-up engine. The engine bay no longer has a big stream of cold air rushing through it, and the warm engine has some time to heat the engine compartment. The small amount of air flowing into the mass-flow sensor gets heated by the engine and warms the air-temperature sensor until it tells the ECU to turn on the Voltage to the VSV. When it's time to go, you put your foot in it and make full boost for an eighth-mile or so until the ECU wises up (Yes, I know the ECU is being fooled into a lean condition, but with all the over-rich protection systems that Toyota builds into the EFI, it comes out about even). Note that this trick only works with any degree of regularity when the airbox has been removed (as in the case of all aftermarket air cleaner ASSEMBLIES. The K&N, etc., replacement filters that use the factory airbox draw most all of their air from outside the fenderwell and thus get the cold air even at idle. So, in a nutshell, nothing is wrong with your MR2T just because the boost is low in the cold! And yes, the computer does control boost (in a global sort of way) with the VSV, but it doesn't control it like the ignition advance or fuel-map. It just has a master high/low range--the rest is plain-old pneumatics. There is no magic "speed-controlled boost limiter" either. You get full boost and power until (and during) 1) you hit terminal-velocity because of wind-resistance, or 2) you hit redline and run out of gears. BTW, don't ever get on the throttle/boost hard until the engine is up to operating temperature; A quick way to kill floating turbo bearings is to force them to cope with 120Krpm turbine-shaft speeds with molasses-like lubricating fluid to keep the whole thing from cooking. NO ONE EXPECTS A SPANISH INQUISITION!------------------ Mike P.: I think disconnecting the Turbocharging Pressure Sensor (TPS) will do exactly what you have said: eliminate fuel-cut and the factory boost-gauge. Just make sure and leave the sensor attatched to the ECU and hook up a section of "dummy" hose to it. That way the ECU will think all is well and you won't have to go through hell to make the engine behave. Plug the end of the dummy hose with a wad of cotton or some-such to keep out the crud. Something that could really be a plus (by disconnecting the TPS from the intake manifold) is if the fuel-pump "overdrive" circuit is referenced to the output of the TPS, our SUPER-RICH air/fuel ratios can be kept at _merely_ rich ;-) during high-boost conditions (12.5+ psi). Here's the way I think it works: When the ECU senses really high boost, it kicks the voltage up on the fuel-pump. The fuel-map is open-loop at this point, and the ECU is just DUMPING fuel into the intake runners. Why the extra fuel? Again, Toyota's protective nature. They know 17.5+ psi of boost on 91-octane pump-gas will blow a 3S-GTE unless it is run WAY rich. For folks like us who want to run racing gas while making high-boost, WAY-rich is bad, because it kills power. I don't see anywhere else where the engine collects boost data, so the TPS must be the reference point for the "high-boost protector." If the TPS is disconnected, the ECU will still get all the mass-flow data it needs to accurately meter (well, merely-rich ;-) ) fuel under all conditions. All of this is my opinion. How 'bout it folks? Other opinions are welcome and needed! Oh; make sure and plug the hose from the intake tract or your car won't idle when it's cold. ;-) Cal, so tired I can't do a spell cheq, Smith '91T P.S. I need either a 1991 Limited-Slip Differential or a 1992-1995 Transaxle and axle-shafts(thanks to Scott MacLean for the advice) with the Limited-Slip Differential option. A 1992-1995 LSD unit will be a good start, but I'll still have to have a 1992-1995 transaxle and axle-shafts to go around it. I am totally serious about this and I need all of your help. If I can do the LSD transplant, I guarantee that I will put my MR2T into the 11's (corr.STP). If someone beats me to the 11's, I will try my darndest to beat them, too. Without the LSD, I can't do it. There is no way I can launch hard enough with an open differential to run high-12's, much less anything faster. Even with 10" wide wrinklewall slicks, I need an LSD. With your help, this can be done. I have several tricks up my sleeve, and none of the guys shown in Turbo have done anything really creative or unique (except that MechTech '93, and it can only make 16psi). This is not a knock to any of the current hot cars--I'm sure they are intelligently designed, well engineered and fast. It is just that I want to show what we can do without putting $10K into the engine bay in parts and labor. Please help. I can't stomach paying the $2000 that my Toyota dealer wants for a new '92-'95 unit, and TRD, etc. aren't of any help. Thank you. ------------------------------ End of mr2-digest V1 #85