High EGT's
Apr 6, 2004 | 09:24 AM
#1
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Joined: Mar 2003
Posts: 21
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From: Moncton NB, CA
High EGT's
I have the S-AFC and Blue top injectors that are supposed to have a flow rate of 305 cc/min. When I approach the rev limiter in 3rd gear, my egt's are climbing to 1500* even though I have maxed out the S-afc at +50%. Is it possible my injectors are too small???
Maybe the ECU detects knock and is pulling the timing. And since timing retard causes the EGT to raise...could it be the timing or the injectors are just too small??? The EGT probe is installed at the exhaust port of cylinder #3.
I wish I had a scan tool to verify that, but I don't.
Any thoughts on this?
My truck is a 2000 4wd 5 speed Tacoma v6 Federal emssions
Chris
Maybe the ECU detects knock and is pulling the timing. And since timing retard causes the EGT to raise...could it be the timing or the injectors are just too small??? The EGT probe is installed at the exhaust port of cylinder #3.
I wish I had a scan tool to verify that, but I don't.
Any thoughts on this?
My truck is a 2000 4wd 5 speed Tacoma v6 Federal emssions
Chris
Apr 6, 2004 | 01:58 PM
#2
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Joined: Jul 2003
Posts: 8,807
Likes: 3
From: Montreal, QC Canada
Originally Posted by juicyfruity
I have the S-AFC and Blue top injectors that are supposed to have a flow rate of 305 cc/min. When I approach the rev limiter in 3rd gear, my egt's are climbing to 1500* even though I have maxed out the S-afc at +50%. Is it possible my injectors are too small???
Maybe the ECU detects knock and is pulling the timing. And since timing retard causes the EGT to raise...could it be the timing or the injectors are just too small??? The EGT probe is installed at the exhaust port of cylinder #3.
I wish I had a scan tool to verify that, but I don't.
Any thoughts on this?
My truck is a 2000 4wd 5 speed Tacoma v6 Federal emssions
Chris
Maybe the ECU detects knock and is pulling the timing. And since timing retard causes the EGT to raise...could it be the timing or the injectors are just too small??? The EGT probe is installed at the exhaust port of cylinder #3.
I wish I had a scan tool to verify that, but I don't.
Any thoughts on this?
My truck is a 2000 4wd 5 speed Tacoma v6 Federal emssions
Chris
Those injectors (unless one is clogged) should be plenty of flow.
Is that %50 long term or short term fuel trim?
Are you using premium fuel too (ie 91+)?
That is definately a lean condition for sure!
Apr 6, 2004 | 02:30 PM
#3
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Joined: Mar 2003
Posts: 21
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From: Moncton NB, CA
Originally Posted by MTL_4runner
Do you have a high output fuel pump installed in there too?
Those injectors (unless one is clogged) should be plenty of flow.
Is that %50 long term or short term fuel trim?
Are you using premium fuel too (ie 91+)?
That is definately a lean condition for sure!
Those injectors (unless one is clogged) should be plenty of flow.
Is that %50 long term or short term fuel trim?
Are you using premium fuel too (ie 91+)?
That is definately a lean condition for sure!
The 50% I'm talking about is the amount of time the injection pulse witdth is augmented. It's the Hi throttle map on the S-AFC... more precisely, at 5000 rpm and over.
Maybe they need some cleaning... but still I have the feeling they are close to be maxed out. I would need to confirm by knowing what's the duty cycle of the injectors.
Apr 6, 2004 | 04:32 PM
#4
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Joined: Mar 2003
Posts: 21
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From: Moncton NB, CA
ooooooookay... I think I might have found what's going on. My MAF voltage is already close to it's maximum of 5 volts under WOT, High Rpm.
sooooo....I can enrich with the s-afc until a certain point.
Lets say the S-AFC converts a 4.8 Volt signal from the MAF and changes it to 5 Volts before it sends it to the ECU...I have reached, at that point, the limits of the MAF...SINCE...
Any High-Throttle values HIGHER does nothing; the S-AFC will not send a voltage ANY HIGHER THAN 5 VOLTS to the ECU.
Anyone knows how much power the newer type MAF can sustain? I know people in the past have used the supra MAF, good for 600Hp... but I can't run it with the S-AFC...
sooooo....I can enrich with the s-afc until a certain point.
Lets say the S-AFC converts a 4.8 Volt signal from the MAF and changes it to 5 Volts before it sends it to the ECU...I have reached, at that point, the limits of the MAF...SINCE...
Any High-Throttle values HIGHER does nothing; the S-AFC will not send a voltage ANY HIGHER THAN 5 VOLTS to the ECU.
Anyone knows how much power the newer type MAF can sustain? I know people in the past have used the supra MAF, good for 600Hp... but I can't run it with the S-AFC...
Last edited by juicyfruity; Apr 6, 2004 at 04:39 PM.
Apr 12, 2004 | 01:09 PM
#5
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Joined: Sep 2003
Posts: 69
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From: SoCal
Hi Chris,
Coincidentally, I just had a recent lean-out problem where my egt's would spike to 1600 at WOT. I removed the SC to diagnose a possible fuel system problem and found out that I had a leaking injector. This incident has finally convinced me to install a fuel pressure gauge as a precaution.
Thanks,
Mike
Coincidentally, I just had a recent lean-out problem where my egt's would spike to 1600 at WOT. I removed the SC to diagnose a possible fuel system problem and found out that I had a leaking injector. This incident has finally convinced me to install a fuel pressure gauge as a precaution.
Thanks,
Mike
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