7MGE sputters and bogs <2500rpm. checked stuff! Edit: SOLVED!!!
- Thread starter PureDrifter
- Start date
It'll be ok. As you said it beats the junk stuff which I commend you for not using. I just dislike using IDC in automotive applications. Prefer Amp PIDG and the right tooling. Why can't you wire it back the stock way?
because the witchcraft the previous owner did with his homebrew alarm system (that i ended up ripping out) prevented it from working, so i did the starter relay mod with a hidden switch. with the STA wire connected the car wont crank but the code goes away.
also, forgot to add that when i got the car running it was getting ~8-10mpg with dead TPS in addition to the plug wires, it was replaced with a new toyota TPS, now getting about 15-16mpg all around, with the sputter.
also, forgot to add that when i got the car running it was getting ~8-10mpg with dead TPS in addition to the plug wires, it was replaced with a new toyota TPS, now getting about 15-16mpg all around, with the sputter.
Well, as 3p said you need STA but it shouldn't prevent the engine from cranking. That fuel economy is piss poor. After it's code free you should work on getting the engine back into fuel control.
jetjock;1683879 said:
The only thing I can think of is he sending the crank signal to the ECU only, and not the relay.
---------- Post added at 06:59 AM ---------- Previous post was at 06:50 AM ----------
PureDrifter;1683208 said:
Voltage. You know there is a potentionmeter in there, right? You could always test off the car by sweeping it on ohms and see what it does. Which would be way better than just a basic number. I suppose you could turn the key on but don't start, and push it open with something, and watch voltage.
PureDrifter;1683396 said:
You have to be at 250 rpm, or something thereabouts. The 250 rpm being the STA signal. When the engine is warm, the sensor for the CSI opens. It just like a turn signal. It will not close until the coolant is cold enough.
-Found a cheap+guaranteed AFM so that's on its way (got it cheap enough to make it an easy sell if mine ends up fine)
-tap will be here this weekend(ish) for me to clear my code 43
-a friend suggested it's an evil EGR malfunction perhaps? (wtf)
-tap will be here this weekend(ish) for me to clear my code 43
-a friend suggested it's an evil EGR malfunction perhaps? (wtf)
EGR will cause a bad idle or stalling if the valve is stuck open. You wouldn't notice it as much as you load the engine.
OK update time:
-new AFM came in, bench tested PERFECT, put it in and the car responds ever so slightly better, but the old one bench tested fine too so idk? (placebo effect?)
-spliced in the STA wire, no more code 34
-re-timed the car, 10* BTDC dead on (was 8-9 before probably due to my timing gun going crazy and having to be replaced)
now the car runs slightly smoother but i still have that weird sputter at idle, and a still present (though oddly, much reduced) part-throttle bucking from 1700-2500rpm. going to double check the plugs and then try to get this beast smogged tomorrow. Will probably replace the EGR since everything else has basically been replaced or tested
thanks for the help guys!
-new AFM came in, bench tested PERFECT, put it in and the car responds ever so slightly better, but the old one bench tested fine too so idk? (placebo effect?)
-spliced in the STA wire, no more code 34
-re-timed the car, 10* BTDC dead on (was 8-9 before probably due to my timing gun going crazy and having to be replaced)
now the car runs slightly smoother but i still have that weird sputter at idle, and a still present (though oddly, much reduced) part-throttle bucking from 1700-2500rpm. going to double check the plugs and then try to get this beast smogged tomorrow. Will probably replace the EGR since everything else has basically been replaced or tested
thanks for the help guys!
The coil pack ground is strictly for EMI, it will run fine with the ground missing.
I assume you have gone through this list and checked everything off.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=16
I assume you have gone through this list and checked everything off.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=16
update x2:
Failed smog again today it came much closer (this time the only reason it failed was elevated HC at both mph tests, raising with each) but didnt quite make it.
i'm stumped, CO and Nox were both perfect, but the HC, even though it came down a LOT since the last test 2 months ago, is still higher than allowed. car still had the sputter when tested.
any ideas??? anyone?
Failed smog again today
it came much closer (this time the only reason it failed was elevated HC at both mph tests, raising with each) but didnt quite make it.i'm stumped, CO and Nox were both perfect, but the HC, even though it came down a LOT since the last test 2 months ago, is still higher than allowed. car still had the sputter when tested.
any ideas??? anyone?
CO is perfect yet the fuel economy is 16 mpg? Was this a loaded mode ASM test? Post all the emission numbers including O2.
Yeah, that does look pretty good. Computes out to being about 1% rich though. You say it was sputtering during the test? Doesn't make sense...the numbers don't show any misfire. Also, fuel economy shouldn't be anywhere near that bad unless you've got a lead foot or something is dragging the car down.
Since the catalyst can mask problems it'd be nice to know what the pre-cat numbers are. What is the average O2 sensor voltage at 2000 rpm taken over the course of a few minutes?
How old is the cat? You would very likely pass with a new one but unless you know what's coming out of the engine replacing the cat could amount to nothing more than a stop gap measure. Myself, I'd fix the idle problem and go from there. It's clearly not right and obvious issues should be corrected first.
Since the catalyst can mask problems it'd be nice to know what the pre-cat numbers are. What is the average O2 sensor voltage at 2000 rpm taken over the course of a few minutes?
How old is the cat? You would very likely pass with a new one but unless you know what's coming out of the engine replacing the cat could amount to nothing more than a stop gap measure. Myself, I'd fix the idle problem and go from there. It's clearly not right and obvious issues should be corrected first.
im going to go back to that whole possibility of the EGR being stuck open for these reasons:
-simple to fix (swap in an EGR, though a pain in the ass, is easy enough)
-high HC due to a lean misfire possibly due to EGR valve being stuck OPEN, causing decreased combustion efficiency, crappy/lumpy idle
-cheaper than a new cat and
-more likely to cure my sputter, as it seems that a jammed open EGR can cause my sputter (apparently?)
might just block it off and see if that helps with the sputter while i look for one or wait for one to arrive.
-simple to fix (swap in an EGR, though a pain in the ass, is easy enough)
-high HC due to a lean misfire possibly due to EGR valve being stuck OPEN, causing decreased combustion efficiency, crappy/lumpy idle
-cheaper than a new cat and
-more likely to cure my sputter, as it seems that a jammed open EGR can cause my sputter (apparently?)
might just block it off and see if that helps with the sputter while i look for one or wait for one to arrive.
I was referring to idle speed, not quality, being wrong. EGR won't cause that symptom and even if it could testing it is much easier than a swap/trial and error approach. And there's zero evidence of lean misfire. NDIR analyzers don't lie. Especially the ones used in California. Me thinks you're barking up the wrong tree but good luck...
words escape me at this point, the lean misfire is in all honesty a best guess at this point(which i realize is mostly negated by the high HC, got the idea from the below quoted source), and there isn't much testing i can do to the EGR (http://www.cygnusx1.net/Media/Supra/Library/TSRM/MK3/EC/EC_015.gif), i've replaced the coolant temp sensor, and tested the vacuum modulator. i'll run one more test on the VSV and see if i can get the car to stall out with vacuum applied to the egr directly (this time with a proper vacuum pump, last time i tried to just apply vacuum from the manifold and nothing happened >.<)
will also check the basics again and see if i can get a video showing the weird miss/sputter it has.
and possibly sacrifice a small goat.
source (for lean misfire theory)
EDIT:
also, as I dislike throwing parts at the car as you mentioned JJ, would I be able to rule out the EGR being stuck open if i concocted a rudimentary EGR-block off using a plate placed at the tube going from the valve -->intake manifold? If i understand correctly, that should allow me to eliminate the EGR possibility completely, without having to either remove/replace the EGR (which is a major pain) and is easily reversible. obviously it would really be a block for temporary purposes to rule out the EGR as a cuplrit.
will also check the basics again and see if i can get a video showing the weird miss/sputter it has.
and possibly sacrifice a small goat.
source (for lean misfire theory)
http://www.aa1car.com/library/vacleak.htm said:
EDIT:
also, as I dislike throwing parts at the car as you mentioned JJ, would I be able to rule out the EGR being stuck open if i concocted a rudimentary EGR-block off using a plate placed at the tube going from the valve -->intake manifold? If i understand correctly, that should allow me to eliminate the EGR possibility completely, without having to either remove/replace the EGR (which is a major pain) and is easily reversible. obviously it would really be a block for temporary purposes to rule out the EGR as a cuplrit.
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The EGR is unlikely to be the culprit here, but since you are not convinced, follow the on-car test procedure here. http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EC&P=14
Also, if its a Cali spec car, the EGR temp sensor should flag most EGR errors with a code 71.
Slightly elevated HC with the car in fuel control is actually one of the toughest problems to solve. You should follow Gary's advice and measure O2 cross counts and average signal level at 2000 rpm, then report back. Also measure Vf in closed loop to see what the ECU thinks your fuel trim numbers are.
If you have access to a gas analyzer, I suggest an oil change, clean the PCV system, a long freeway drive of 30 minutes, and then a retest, you might just pass.
Also, if its a Cali spec car, the EGR temp sensor should flag most EGR errors with a code 71.
Slightly elevated HC with the car in fuel control is actually one of the toughest problems to solve. You should follow Gary's advice and measure O2 cross counts and average signal level at 2000 rpm, then report back. Also measure Vf in closed loop to see what the ECU thinks your fuel trim numbers are.
If you have access to a gas analyzer, I suggest an oil change, clean the PCV system, a long freeway drive of 30 minutes, and then a retest, you might just pass.
Yes, you can remove the bolts on the intake manifold, loosen the couping nut if you must, and slide something like a piece of sheet metal in there but the book has a positive test of the entire EGR system:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EC&P=13
As I said though bad EGR will not result in high idle.
True lean misfire does not occur until the A/F ratio is much leaner than what you have and it'd result in much higher O2 and HC than what you're seeing. NOx would also be up there.
Misfire for other reasons would also result in increased HC and O2 although not as high. And while it's true the cat may be oxidizing excess HC, computing lambda makes the cat transparent. In your case it shows the engine to be slightly rich. Again, it'd be interesting to know the average steady state O2 sensor voltage.
I can understand failing emissions just over the wire but it's powerful queer the engine could run as you say (especially during the test) while displaying such good combustion efficiency. Nor should the fuel economy be poor with those numbers. Just doesn't make sense. Maybe we define stuttering in different ways. A video with sound could indeed clear that up.
Edit: Beaten by 3p. Thanks Jon. I avoided typical causes of slightly elevated HC only because the engine running poorly with such good numbers interests me more at this point
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EC&P=13
As I said though bad EGR will not result in high idle.
True lean misfire does not occur until the A/F ratio is much leaner than what you have and it'd result in much higher O2 and HC than what you're seeing. NOx would also be up there.
Misfire for other reasons would also result in increased HC and O2 although not as high. And while it's true the cat may be oxidizing excess HC, computing lambda makes the cat transparent. In your case it shows the engine to be slightly rich. Again, it'd be interesting to know the average steady state O2 sensor voltage.
I can understand failing emissions just over the wire but it's powerful queer the engine could run as you say (especially during the test) while displaying such good combustion efficiency. Nor should the fuel economy be poor with those numbers. Just doesn't make sense. Maybe we define stuttering in different ways. A video with sound could indeed clear that up.
Edit: Beaten by 3p. Thanks Jon. I avoided typical causes of slightly elevated HC only because the engine running poorly with such good numbers interests me more at this point