View Full Version : what would cause this
05-21-2003, 11:23 PM
ok heres the deal
occasionally my car runs great i mean pulling hard in every gear anywhere in the gear however sometimes it doesnt have so much power i was wandering what would cause this i mean my car would run great then i would shut it off for maybe just a sec start it back up and it seems to not have as much power i could really use some help because it gets really annoying sometimes when im trying to mess with a freind driving behind me and i dont hav the power to pull on them like i know i can
thanx for the help
05-22-2003, 08:13 AM
do 95's have a EGR system?
if they do, and yours is getting cloged up, that can cause it.
a cracked vacume hose someplace could do it too, if its a crack thats small and doesn't open up all the time, but when it does could cause lack in power..
this is my stab at it
do 95's have a EGR system?
this is my stab at it
95 ? :? :wink:
05-22-2003, 11:17 AM
Two things come to mind (cause I've had the same issue with my 1985 Supra). First thing, heat. On hotter days the engine compartment can get heat soaked (especially if you have headers with no heat sheilds like I did). As a result the car sometimes felt quicker when I would first start driving it in the morning (coming out of a cool garage) or on cooler days in general. Try to make sure your cars cooling system is up to snuff and that your getting nice cool outside air entering the air filter (ie. cold air box, or ram air etc.....). Next possibility I would say is gas. Are you putting in high octane gas, or just regular? Using the cheaper stuff can cause the car to pull the timing back, thus loss of a couple of hp. I've even noticed that using regular gas in my 1990 Celica changes on a tank to tank bases depending on how fresh the gas is or what station I fill up at. I would say if you are not using the highest grade octane in your area to try it for several tanks and see what happens. And as usual make sure that the general state and tune of the car is in tip top shape (clean filters, new cap/rotor and spark plugs, fresh oil............). Good luck, hope this helps.
05-22-2003, 11:58 AM
the tune up is up to date and everything and the cooling system is up to par( new radiator and water pump) it actually runs cooler than half way on the guage
the vacuum hoses could possibly be to blame since they are the original hoses and all as for heat soak i have had that happen to me before so i know that thats not it
i plan on doing a cool air mod very soon just havent got around to it yet due to the fact im putting in a 6m very very soon
thanx for all help it is greatly appreciated
05-22-2003, 06:43 PM
When was the last time you replaced the oxygen sensor? It could be starting to go bad. I have been going through mine one system at a time, and am finding out that the 5M runs stronger than a lot give it credit for, with intake and exhaust modifications. There is a lot to go wrong in old cars like these, and it's usually a combination of things.
05-22-2003, 07:21 PM
If the EGR passage is clear (most higher mileage mk2s are completely plugged with soot), then a valve thats not closing all the way at full throttle could reduce performance. But that doesn't jive with the problem only appearing when the car is restarted warm. O2 sensor provides feedback only in steady state operation, not when accelerating so thats not it either. Sounds to me like your car is going into warm-up mode when the car is started regardless of the engine temperature. A too rich mixture or too far advanced timing when the engine is already warm would reduce performance. Test the cold start injector time switch and the temp sending unit with a multimeter as in the TSRM. Perhaps someone could post the link to the online manual if you don't have your own copy. Good luck.
05-22-2003, 08:11 PM
Online tsrm =
05-22-2003, 09:43 PM
Are you only losing power after restarting the engine, or do you lose power under other conditions as well?
05-22-2003, 11:26 PM
im not sure about the o2 sensor as i have not changed it since i got it in august and im not sure if the owner before me had changed it or not it could be it if so i just gonna get a new one and put it in the 6m i have sitten at my house awaiting an install
i think that my cold start injector or related system may also be going out because when i do start my car for the first time in the morning it will start like it is supposed to but immediately after start up it will stutter and idle at 400-500 for a second then rev high like it is supposed to(i think)
any who i hope you can help i just want it to run its best till i get the 6m in so thanx for the help
05-24-2003, 10:02 PM
Try checking the AFM flap and see if it moves freely throughout it's full range of travel without sticking.
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