cruise throttle surge

[1995 toad]

one can even drive all week with the DLC Diag jumper in place, and see 12  all week and then on moment bam , new code pops.
cold idle can be 1000 to 1500 rpm colder the block that faster.
hot is 800 with all accessories off.  (means no AC on this car)
many things cause failed idle regulation.
coolant not hot, 180f.
TPS idle switch not closed, and at 0vdc.  if 5vdc idle is cancelled.
air leaks. (aka vacuum leaks from anywhere to the plenum)]
ECU in limp home mode.  not 12, means that , mostly.
if way below 800 even 400 , egr main valve  leaking like mad.
leaking injector or clogged, may cause low idle speeds. below 800 hot.
misfiring engine, blew 800.
1000 hot, no AC turned on is ISC is off line or stuck open.
or engine super rich and huge vacuum leaks at the same time.
The ECU wants to control idle at 800 hot and aggressively modulates the ISC valve to do that.  we see it can do that. only why remains.

Idle was stable today when cold started missing through warm up idle stayed fine once warm sounds like it is the egr from what you have explained. What does the vacume line do that comes from a valve at the front of the intake and goes through a vacuum  dashpot and is hooked to the egr with the same hose... will clean the egr and se what happens

took the egr off.. hose ends almost plugged. tried cleaning valve, could not get it to stop leaking. bought a new one and got it installed and everything cleaned and flattened. new gaskets. btw the top bolt was also loose when I removed it... hope this fixed it. haven't had time to drive it yet

[1995 toad]

one can even drive all week with the DLC Diag jumper in place, and see 12  all week and then on moment bam , new code pops.
cold idle can be 1000 to 1500 rpm colder the block that faster.
hot is 800 with all accessories off.  (means no AC on this car)
many things cause failed idle regulation.
coolant not hot, 180f.
TPS idle switch not closed, and at 0vdc.  if 5vdc idle is cancelled.
air leaks. (aka vacuum leaks from anywhere to the plenum)]
ECU in limp home mode.  not 12, means that , mostly.
if way below 800 even 400 , egr main valve  leaking like mad.
leaking injector or clogged, may cause low idle speeds. below 800 hot.
misfiring engine, blew 800.
1000 hot, no AC turned on is ISC is off line or stuck open.
or engine super rich and huge vacuum leaks at the same time.
The ECU wants to control idle at 800 hot and aggressively modulates the ISC valve to do that.  we see it can do that. only why remains.

Idle was stable today when cold started missing through warm up idle stayed fine once warm sounds like it is the egr from what you have explained. What does the vacume line do that comes from a valve at the front of the intake and goes through a vacuum  dashpot and is hooked to the egr with the same hose... will clean the egr and se what happens

I replaced the egr and it has been running ok. the nag light came on at 170000 miles cured that... after about 75 miles of driving on the way home today the cel came on today... no issues the rest of the way home. so I pulled the codes and it says 51 egr failure.. ?? checked all the connections...

[1995 toad]

one can even drive all week with the DLC Diag jumper in place, and see 12  all week and then on moment bam , new code pops.
cold idle can be 1000 to 1500 rpm colder the block that faster.
hot is 800 with all accessories off.  (means no AC on this car)
many things cause failed idle regulation.
coolant not hot, 180f.
TPS idle switch not closed, and at 0vdc.  if 5vdc idle is cancelled.
air leaks. (aka vacuum leaks from anywhere to the plenum)]
ECU in limp home mode.  not 12, means that , mostly.
if way below 800 even 400 , egr main valve  leaking like mad.
leaking injector or clogged, may cause low idle speeds. below 800 hot.
misfiring engine, blew 800.
1000 hot, no AC turned on is ISC is off line or stuck open.
or engine super rich and huge vacuum leaks at the same time.
The ECU wants to control idle at 800 hot and aggressively modulates the ISC valve to do that.  we see it can do that. only why remains.

Idle was stable today when cold started missing through warm up idle stayed fine once warm sounds like it is the egr from what you have explained. What does the vacume line do that comes from a valve at the front of the intake and goes through a vacuum  dashpot and is hooked to the egr with the same hose... will clean the egr and se what happens

I replaced the egr and it has been running ok. the nag light came on at 170000 miles cured that... after about 75 miles of driving on the way home today the cel came on today... no issues the rest of the way home. so I pulled the codes and it says 51 egr failure.. ?? checked all the connections...

[1995 toad]

well I took the new egr off and it seals off the passage from the exhaust to the intake but the port from the intake doesn't seal off the vacuum when the egr is closed so the idle is low..
can I block off the egr and run it that way..?

[fixkick]

well I took the new egr off and it seals off the passage from the exhaust to the intake but the port from the intake doesn't seal off the vacuum when the egr  is closed so the idle is low..
can I block off the egr and run it that way..?

but the port from the intake doesn't seal off the vacuum?
please explain, this. more details.

[1995 toad]

well I took the new egr off and it seals off the passage from the exhaust to the intake but the port from the intake doesn't seal off the vacuum when the egr  is closed so the idle is low..
can I block off the egr and run it that way..?

but the port from the intake doesn't seal off the vacuum?
please explain, this. more details.

the port in the egr that comes from the intake manifold does not seal when the egr is closed. so it has a vacuum leak through the egr

[fixkick]

well I took the new egr off and it seals off the passage from the exhaust to the intake but the port from the intake doesn't seal off the vacuum when the egr  is closed so the idle is low..
can I block off the egr and run it that way..?

but the port from the intake doesn't seal off the vacuum?
please explain, this. more details.

the port in the egr that comes from the intake manifold does not seal when the egr is closed. so it has a vacuum leak through the egr (where exactly is this LEAK)

the 1995 had 2 systems used, early and late seen here,, part ID 50 is missing it is early 95. (what I call the quad port)

https://fixkick.com/EGR-Gen2a.html

it idle and not moving the car, 0mph there is no vacuum ever past the VSV valve.
hose 16 is ported vacuum "P" at idle The TV in the TB is closed and there is no vacuum to the hose 16.
the nose 16 and 19 /22  are dead if engine not hot (180f coolant) car not idling, (and not moving) the EGR only works moving hot engine, over 0mPH.
then opens and ported vacuum lands at modulator 8. (using cat back pressure to see engine load)
if the cat is not missing or hose 13  missing or mpt cracked, then part 8 , sends vacuum to EGR MAIN #5 opens, and opens based on CAT back pressures, (then at WOT, the vsv closes)
hose 13 is exhaust back pressure , is what I call the bark tube,  #4 exhaust only Putt Putt Tube. this does the modulation. IF THE CAT IS DEAD so be BARK SO BE MOD SO BE EGR.


late is yours. edited




if any of  this fails DTC 51 happens. (if you just unplug hose 23 and put screw or golf tee in the end , EGR main stays closed and stays that way for ever. code 51 full time.

[1995 toad]

well I took the new egr off and it seals off the passage from the exhaust to the intake but the port from the intake doesn't seal off the vacuum when the egr  is closed so the idle is low..
can I block off the egr and run it that way..?

but the port from the intake doesn't seal off the vacuum?
please explain, this. more details.

the port in the egr that comes from the intake manifold does not seal when the egr is closed. so it has a vacuum leak through the egr (where exactly is this LEAK)

tell what does not seal,  be accurate, the drawing NOW matches your car, LATE 95.5 calif version of car it  is. MONO PORT EGR, vastly better than the early ones.
HOSE #50  (A STAINLESS STEEL PIPE IT IS), IS UNDER FULL PLENUM VACUUM AT ALL TIMES RUNNING.  SO THE 2 GASKETS ON SAID PIPE MUST NEVER FAIL.
THE EGR IS UNDER powerful back pressure at the EGR #5 main. left side port (drivers perspective left , driver side, usa)
The EGR main is 100% closed, at idle, and even key off. but at idle the valve inside EGR #5 main is closed and that exhaust huge pressure never lands on pipe 50
and when that happens closed MAIN the PIPe 50 is under full engine intake plenum, vacuum 19"HG at idle.  and there are vacuum leaks in pipe 50 or hell will be paid for that.
that is how this works , how the mod works is fully covered on my EGR pages. fixkick.com type EGR in the search box (hints)
see the P mark on end of hose 16? that means ported vacuum that means no VACUUM there at idle. and THat VSV valve is closed at idle and WOT, so vacuum is DOUBLE DEAD
at idle. (if key is off VSV is not closed, it vents with no DC 12v power until ECU turns ON)

 



if any of  this fails DTC 51 happens. (if you just unplug hose 23 and put screw or golf tee in the end , EGR main stays closed and stays that way for ever. code 51 full time.
Many 92-98 cars have the above setup and many old quad port egr, are replace with the above better setup. (this mono port intake is best)

the vacuum that leaking is coming from the metal line that leads to the intake. (how to did you prove that? ?)
when the egr valve is closed the vacuum leaks out of the valve.
the exhaust port side is sealed from the intake side of the port.

I do not unerstand any of that, use ID numbers when talking about such complex EGR issues. please.
if pipe 50 leaks AIR , as it surely will of both gaskets are bad or missing #51,  for SURE.  if you have a leak at 50 tell how you know that.?  I can not guess testing methods , they must be told. please elaborate what you did. testing.
Pipe 50 is under hard vacuum at all times running at idle, if the EGR opens , it is now under hard flowing exhaust, there is no AIR here ever, its vacuum hard or exhaust. in pipe 50
in fact 50 is the mono port EGR injector PIPE<

[fixkick]

the vacuum that leaking is coming from the metal line that leads to the intake. when the egr valve is closed the vacuum leaks out of the valve. the exhaust port side is sealed from the intake side of the port. (I haVE NO IDEA WHAT THIS IS.
WE NOW LEARN THAT THE CAT IS MISSING OR GUTTED, AND THAT MEANS THE MOD IS NOW DEAD.  no more 0 to 2 psi exhaust back pressure from hose 13 .
so EGR is  now dead forever, due to that one missing fact not told post 1.  oops

i

here is how MOD works if  BARK hose is dead, (cat missing or gutted, does that every time) there can be no EGR no Modulation possible making EGR main DEAD. and code 51 DTC.

[fixkick]

yes EGR is complex on these years. 89-98.
in latter years ( or all J10 or J20 engines up)
they ended the VAC MAGIC EGR HORRORS. 1999+
they run the mAIN with an electric motor, and no other parts at all.  with just 1 part. (main)
this one part , is controlled by the PCM (ECU) the ECU now does engine load calculations fully.  and runs the EGR motor as need be all pure  magic of software(firmware)

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[url=https://fixkick.com/sensors/EGR/90-95/SLIDE/html/image_7.html]here is the ported vacuum port EGR as you can see it is blocked at idle this ends all EGR actions at idle for sure, then VSV does same , is closed at idle, and WOT.
I forget i had so many photos of EGR bits.
the idles to high failure, (not you) but is caused by this?

ah the moving rule to test EGR 100 % parked is not easy, here are the FSM words, (for those dohttps://fixkick.com/sensors/EGR/90-95/SL...ge_13.htmling smog checks this is how,before that doing this first, not last)
omg I even have this beauty on my EGR pages. check this  out , this is the mono port, late 1995 and to 1998 G16b

the hole on the left barks hard, #4 exahust full pressure against the CAT BRICK , up to 2PSI in fact.
the hole on the right is under hard plenum vacuum at all times at idle and at up to 2 psi exhaust flow if moving, only hot engine.
The 3 gaskets MUST NOT BE MISSING OR THIS FAILS HARD.
This is also called the CALIFORNIA intake manifold 1995.5.   and is the best, and used until 1998.  we can even install this on 1992 engine and works, better. kicking quad ports to the crub is great trick. (EGR on G16 here are complex,) the CAT must be good or all this fails. that is how EGR works here and same deal on 95 Toyota's too.  it's not rare its OLD TECH.