Jersey Posted August 6, 2003 Author Share Posted August 6, 2003 Checked/cleaned/adjusted TPS. Working good - on and off. Fuel pressure is good all around. What gets me is the fact that if i create the vacuum leak, it creates more vacuum on the gauge and runs perfect. Also checked the (stock) FPR and it also is working properly. I understand what your thinking Forrest - too much fuel pressure and she'll run rich at idle. But would this create less vacuum in the intake? Quote Link to comment Share on other sites More sharing options...
Afshin Posted August 6, 2003 Share Posted August 6, 2003 I think that ANYTHING causing your engine to idle low and poorly would cause your vacuum to drop, when you create a vacuum now (letting more air in) you improve your A/F ratio which increases your RPM and hence the amount of air that is being sucked into the engine which results in overall increase in vacuum. In other words your vacuum change is a reflection the amount/velocity of air being sucked in, which at idle (fixed throttle plate position) relates directly to your engine RPM. Quote Link to comment Share on other sites More sharing options...
Jersey Posted August 6, 2003 Author Share Posted August 6, 2003 Sorry Afshin i didn't reply to your previous post..guess i was posting at the same time. Anyway, I did not put a meter on the HTS to check it but i did pull it off while running and she died instantly...which doesn't really mean much. The only reason why i didn't meter it is because i figured it really shouldn't have anything to do with the vacuum problem...And now reading your second post, maybe the vacuum problem is the effect, not the cause. I'm thinking the low vacuum is causing my low, eneven idle, rich problem but i think i've exhausted every possibility air wise, except for maybe a valve issue so, now i'll be going home checking the HTS with my meter. I did the ECU/harness unplug/clean job on all three connectors and at the AFM. AFM flap operating smoothly but did not manually open it up a little more while running. I will check the HTS tonight with my meter. Thanks for the input. Quote Link to comment Share on other sites More sharing options...
Afshin Posted August 6, 2003 Share Posted August 6, 2003 Hi Jersey, I still don't think that your primary problem is low vacuum. If you had low vacuum from all sort of horrible things like valve or piston or ring problems, the problem would only get Worse when you add a vacuum leak. Since the opposite happens in your car, it only makes sense to me that the primary problem is too much gas/too little air. This would explain the marked improvement you are getting with the addition of unmetered air(vacuum leak). I'll continue to think more about this problem and let you know if I come up with any other ideas. Quote Link to comment Share on other sites More sharing options...
Jersey Posted August 6, 2003 Author Share Posted August 6, 2003 Thanks for the input and thoughts Afshin, and everyone else that's subbmitted suggestions. Now i'm hoping Head Temp Sensor. We'll see what values it reads tonight. Quote Link to comment Share on other sites More sharing options...
fl327 Posted August 6, 2003 Share Posted August 6, 2003 I always thought that when the CHTS goes bad, car bearly wants to run, and when it does, runs so rich that black smoke shoots out the tailpipe like a smokescreen. TPS could be bad, but you also said power was good. If you need one, I have 26 of them, last time I checked. Hope you get the show back on the road, we are all dying to see your car rip mid 12s, where even some of the really great weekend warriors on this site havent been on the t3-and definitely not with stock efi. And in two months-Ill be ready to join you. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted August 6, 2003 Share Posted August 6, 2003 I have to agree with Afshin, the low vacuum is a side effect of too much much fuel or too little air. You may have one or more stuck injectors - check out how they sound. I think if one was stuck, it might still click, but it would sound differently than the others. Just a thought. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted August 7, 2003 Share Posted August 7, 2003 heh just like what I think is wrong with mine. Did you check the plugs? gonna have to read back and see if you mention it... like I said on my other thread I'm almost positive I have a stuck injector... one plug came out very black and sooty while the other five looked perfect. I'm sure that's causing my stumble, idling problems... just about everything wrong with my car right now! Quote Link to comment Share on other sites More sharing options...
Jersey Posted August 7, 2003 Author Share Posted August 7, 2003 Ok. Update...broke out the meter last night and started checking the head temp sensor. There's definetly something wrong...but it's not with the sensor. I did the tests exactly how the FSM says and the readings it's giving me are right in the curve it should be at different coolant temps. Here's the catch...When i plug the 16 pin connector back into the ECM with the ignition off, the reading stays the same. When i turn the ignition into the run position, the meter turns to OL. Same thing happened when i started the car up and ran it...no nice readings to the ECM like it does when the key is off. Also, the readings off the back of the sensor with the plastic plug unplugged are right in the zone so i know it's working properly. So, i started doing some investigating and found that if i put one leg of my meter on the black wire off of the head temp sens and the other to the neg side of the battery, with the key off, it has continuity BUT...say i put the headlights on....now i lose continuity between the battery neg and the black off the head temp sensor. Strange huh? Anytime i pull power from the battery or cause more resistance on the ground circuit, the black head temp wire gets a major increase in resistance. And of course, when i turn the key into the "on" or "run" position - running or not, and components start drawing from the battery (fuel pump, relays, gauges...etc), the correct signal from the head temp sensor wire (yell/green) never reaches the ECM. So now i figure it's got to be some kind of ground issue and start grounding everything around the entire car - ground wire from battery to engine to frame to body to intake...everywhere and it really didn't make much of a difference. It did a little but not much at all and didn't help with the values coming out of the HTS. This is what i DID find...I yanked my battery out and found that it basically blew it's load and is leaking acid down the back side of it, all down the nice new firewall i just welded in there a couple of months ago. Nice huh? So, this is what i'm thinking...The battery's got a dead short in it and causing my problems. Sound good? Yeah right...i'm wishing it were that easy but, i am going to put a new battery in her tonight. I'm also hoping it's not a wasted ECM, which i ripped apart last night and didn't see/smell any burnt components. I know, it doesn't mean everything in there is OK but it makes me feel better for the moment So...any ideas out there? Has anyone else put a meter on the yell/green and black wire off of the head temp sensor wire while it was running? If so, was it showing the resistance it should or close? Thanks in advance. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted August 7, 2003 Share Posted August 7, 2003 Well, a bad battery will certainly cause problems in the ECU. I tried to start on a mostly discharged unit, and the car was just wacky. Verify the voltage. If it is below 12V, you may have issues. But as far as measuring continuity, you can't reliably measure it with live circuits. Any voltage externally applied will screw with your meter. Start checking stuff with the voltage meter when you are testing live circuits. Quote Link to comment Share on other sites More sharing options...
Jersey Posted August 7, 2003 Author Share Posted August 7, 2003 Will do Sleeper. Quote Link to comment Share on other sites More sharing options...
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