cruise throttle surge

[1995 toad]

that is what I am talking about. (what ?)  are you telling me you have PIPE ID#50 or not?)  please tell me this? and part 36.  (if yes it is the full blown CALIF car version code E33)

that seems like that (what does that mean? (name the part ID please) should seal when the valve (MAIN5?) is closed or there is a vacuum leak and idle problems when warm..

put another new valve in tonight.  (which valve there are 3 VALVES at least. ,main, MOD and vsv)
seemed sealed when egr closed... (please tell exact part there are many)
we will see what happens...

does the probe signal the ecm that the egr is bad?  (the probe is the CALIF EGR thermister sensor, and if the ECU sees the EGR fail to warm the sensor BAM CODE 51)
What makes the code get sent for the egr..  (easy the ECU scans it any time it activates the EGR over 0mph,  and if the EGRT probe is missing or dead, or fails to shot HOT, CODE 51.
Great question and the 96+ uses EGR MAP sensor and does 2 tests not one to test EGR (harder to pass too)


That the EGR SYstem evolved, by generations and by CALIF laws that latter were adopted by FED LAw, EPA. My ECU pages show those, and when they happened.

The first car 1992 (16v) has no pipe 50, nor has EGRT thermo sensor ID #36  (engine swaps happen and I can not see your engine and what is there in full)
the CALIF laws, added 36 and then adopted USA wide, (see function matrix here)
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there are 2 kinds of Customers here,  one that can't pass SMOG IM240 tests. (in calif or any state , many that make you do thata)
then there are other folks  with EGR parts leaking or parts stuck open,.  causes vacuum leaks on any 16valve G16 invites lean mix and performance issues. (bad gasket 6)
or both, reasons.  (smog test and engine problems) The EGR that sticks open can stall and engine. (most time EGR main is BAD for that)


the EGR main can stick or leak at the EGR MAIN valve, this is very common and the engine wants to stall.
EGR MUST BE disabled (ecu logic does that) at idle if not every stop light you stall. (so common this)

vast  and valid problems are associated with the EGR.
gasket 6 missing or cracked or not the high temperature rated fails fast  and sucks air (vacuum leaks)

to test THE EGR for (non smog test failure reasons ,just  testing for drive ability  issues) is easy. kinda....

1 : make sure gasket 6 is not missing or a wrecked and sucking AIR.  (good and valid gaskets work best , the look silver'ish,  the silver is heat proof !!!
2: make sure the EGR main #5 is not body cracked, yes they can crack. and suck air and makes the MAF reading now wrong,. for sure at idle. and never good.
3: then  with engine dead cold (no burn fingers) push the EGR 5 test ring inward and release, make sure the valve goes thunk each time and seals or it is hopeless to use this valve it MUST CLOSE and stay closed at idle.  ONce 100% sure the MAIN5 is closed, pull the vacuum line 23 and GOLF TEE IT, (or use screw that seals the end of 23) now EGR IS DEAD but CLOSED!
4: drive  the car if you have problems with misfire , bogs,  or hesitations in power at the the throttle , that means you have other problems not associated with EGR.


for smog testing , code 51 is that.  to make EGR actually work start here on my Gen2 page.  (how to make code 51 go away as smog states mandate)
[url=https://www.fixkick.com/EGR.html]see the first line that shows stall test.


IF THE ENGINE FAILS WITH EGR  defeated, there are vast things that cause cruising SURGE.

1.  Not violent misfire (like bad spark plugs or gapped wrong, or spark wires bad, cap and rotor.(old)
   
2. smooth SURGE would be,  (well a huge list but here) #1 is low fuel pressure or FPR bad causing that. FPR must work or fueling correctly is hopeless, and FPR  all love to fail NOW.
   
3. The car is 1995 we have vast FPR failures,  doing the pressure tests,  its like omg the FPR IS DEAD< , and if the vacuum nipple to the FPR is leaking fuel it is DEAD.
   
4. injector leaks or clogs, mostly from bad fuel or parking car for over a year. unused.
   
5. MAF dirty (ever clean it? it is a service POINT) or bad, it must measure air flows correctly (mass air flow ) sensor. or Fueling will be iffy. (can be)
   
6. O2 (oxy) sensor front (B1S0 ) bad, will make any car fuel wrong. seen cards with all above bad, after all the car is  25 years old.
   
7. Does engine have full WOT up  hill performance full power wide open throttle and no BOGGING and no violent misfiring?
   
8. The surge is most time fuel related, to little, is what I'd guess, called AFR too lean, (air fuel ratio) Id have to drive car to say that.  feel it I can.
   
9. There is a thing called (me) TIP IN Hesitations, when you move the right foot cruising the engine hesitates but catches up, this is TPS bad. The TPS in this mode is ENRICH mode.
   
10. if the surge is steady foot then it is not TPS caused,(easy no/?)"mostly"
    
11. Engine not reaching 180f and holding normal coolant temps.  it must rise , hit 180f and hold, at all times. (dash gauge holds mid scale, yes and holds) Coolant temp gauge.
    
12.  (yes, weak engine,  low compression on 1 to 4 cylinders, or all 4, and timing belt slipped.)
    
13. I;m sure i missed some here,  but I will think on this for a day.....
    

that's what im talking about is line 50     vacuum coming from it
valve im talking about is the egr    not sealing vacuum coming from 50.
the surge or miss went away with the first new egr 
after about 75 miles the cel came on with 51 code and idle would go to about 300 or 400 then recover after about 30 seconds or so to 800 other than that it ran great. none of the idle problems show till warm
pulled the new egr and found vacuum from line 50 leaking through the egr valve while at idle and exhaust side closed.
installed new egr and haven't driven it yet. 
the only non stock thing is a gutted cat do to a slide off the road landing on cat with curb. it had been gutted for about 2 years prior to all these issues.
At idle I have a fairly good vacuum (haven't put a gauge on it but holds a finger tight when covered) 
also at idle I have fairly good Exhaust pressure ( again no pressure gauge).
Don't need to pass smog

How do I test the egrt probe? is it a on or off switch or at different temps, different resistances
if the egr doesn't seal the vacuum off that comes from hose 50 what filters that air. ie like the vacuum coming to valve that's turned on by the exhaust pressure to activate the egr.

thanks much I appreciate your time