no more EGR ??

[Jolly Roger VX'er]

Guys, EGR's main purpose is to reduce the combustion chamber temperature. If you block off a working EGR, you will actually LOSE power, as the combustion chamber will be that much hotter when you step on the throttle. If blocking the EGR appears to have improved the engine, that's because there was something wrong with your EGR system in the first place.

Nate

I agree to disagree. The EGR's main purpose is emission control by "reburning" the exhaust gasses entering the EGR pipe on the passenger side of the engine block. It achieves this by sending exhaust gasses to your EGR valve which sends them into your intake to be sucked back into your cylinders for re-burning. The result is lower cylinder temperatures because the cylinders are not burning at high efficiency due to the "smothering" going on. Eliminate the exhaust going in during the intake stroke and you have only fuel & air going in. I've done this mod on my '82 Trans Am, '88 Fiero, '79 Bronco all with improved hp as felt by my butt dyno. I don't care if nobody here does it...I'm doing it. I'm only concerned with my PCV functioning which in my opinion could lead to oil burn-off if the EGR is blocked & the PCV ceases to function. THis already has happened in the past...that's why I have a breather cap installed so I can SEE when this happens...plus pull the little dipstik thingie to check the oil level.

[Jolly Roger VX'er]

uh oh. I got a P0401 code thrown on my way to work tonight. "EGR Insufficient flow rate detected". I guess not...with a fricken block-off plate installed! Now I got to decide if how good she runs now is worth either ignoring the light (on most of the time anyways for EVAP fault over last few years!) or removing the bulb

I didn't anticipate flow rate detection as on previous vehicles the EGR had no way to detect this.

I think I'm gonna pull the bulb as I tried once to fix the EVAP problem (broken wire discovered when we dropped my fuel tank to mount my rear baja style tire carrier...there is a T.S.B. out from ISUZU concerning this broken wire too...fixed wire...EVAP still fails! Figure it most likely is the purge valve.)
Figure if I pull the bulb I'll do periodic code reads (what I do now anyway since light is almost always on!)


On a final note...I swear my gas mileage today was better than normal as I usually can't get more than 40-50 and rarely 60 miles on the first quarter tank...today I've got 45 and its showing 1/8 tank consumed.

[Ldub]

On a final note...I swear my gas mileage today was better than normal as I usually can't get more than 40-50 and rarely 60 miles on the first quarter tank...today I've got 45 and its showing 1/8 tank consumed.

That sounds about right. My mileage is starting to come up too, as the cold weather subsides...almost identical to yours.

I'm gonna re-set the ECU before I head out Moab way, to see if I can pick up a few mpg.

[Joe_Black]

I agree to disagree. The EGR's main purpose is emission control by "reburning" the exhaust gasses entering the EGR pipe on the passenger side of the engine block. It achieves this by sending exhaust gasses to your EGR valve which sends them into your intake to be sucked back into your cylinders for re-burning. The result is lower cylinder temperatures because the cylinders are not burning at high efficiency due to the "smothering" going on. Eliminate the exhaust going in during the intake stroke and you have only fuel & air going in. I've done this mod on my '82 Trans Am, '88 Fiero, '79 Bronco all with improved hp as felt by my butt dyno. I don't care if nobody here does it...I'm doing it. I'm only concerned with my PCV functioning which in my opinion could lead to oil burn-off if the EGR is blocked & the PCV ceases to function. THis already has happened in the past...that's why I have a breather cap installed so I can SEE when this happens...plus pull the little dipstik thingie to check the oil level.

JollyRoger you're right on as to the function of the EGR as it's an emissions-control technique and has no benefit to the function or performance of the engine. I too ditch the system wherever and whenever I can, but haven't on our VX's as it hasn't faulted yet. If it ain't broke! You shouldn't be concerned about PCV failure related to the EGR block-off as the two are not related functionally. The PCV operated from engine vacuum tapped at the intake to provide "Positive Crankcase Ventilation". The "Positive" is a bit misleading as it doesn't impy positive pressure on the crankcase side but rather an authorative ventilation method as provided by engine vacuum. Replace your PCV grommet every couple years and change the PCV itself every other oil-change and you'll have no problems unless you get a defective new PCV, but that's why you should check your oil regularly too! Otherwise you could retrofit a crankcase breather to the valve cover in lieu of the PCV.

For those using an EGR block-off we just need to determine what signal the ECU is looking for from the EGR so it can be "fooled" into thinking it's operating normally.

[Jolly Roger VX'er]

JollyRoger you're right on as to the function of the EGR as it's an emissions-control technique and has no benefit to the function or performance of the engine. I too ditch the system wherever and whenever I can, but haven't on our VX's as it hasn't faulted yet. If it ain't broke! You shouldn't be concerned about PCV failure related to the EGR block-off as the two are not related functionally. The PCV operated from engine vacuum tapped at the intake to provide "Positive Crankcase Ventilation". The "Positive" is a bit misleading as it doesn't impy positive pressure on the crankcase side but rather an authorative ventilation method as provided by engine vacuum. Replace your PCV grommet every couple years and change the PCV itself every other oil-change and you'll have no problems unless you get a defective new PCV, but that's why you should check your oil regularly too! Otherwise you could retrofit a crankcase breather to the valve cover in lieu of the PCV.

For those using an EGR block-off we just need to determine what signal the ECU is looking for from the EGR so it can be "fooled" into thinking it's operating normally.

Thanks Joe! I went the blocking route because @ 87,700 miles and the EGR acting up, my VX really could use a new one if the EGR is to remain operable.

My experience is that EGR's degrade over time (internal spring tension fades...pintle starts sticking...etc.). When the spring starts weakening you get valve "flutter" when the valve is supposed to be closed and that's when the vehicle starts things like hesitation, bogginess, lower mpg...etc. I've had good luck in the past just blocking them off when they needed replacement (saving like $150) plus, so far they do no emissions testing where I live.

I've lived with a faulty EVAP system (also doesn't affect how vehicle runs...emissions related only) for about 2 years now and the check engine light comes on for that...goes back out after like 25 starts...comes back on when it fails that particular test again!

I'm getting much better gas mileage today although I believe it is a combination of things...nicer (warmer) weather, summer blend gas, EGR was not operating as it should (now blocked off it is essentially @ the very least "closed" when it supposed to be ).

2nd day driving with EGR blocked and she feels like she got a tune-up!

Oh yeah...I've gotten stung twice with defective new PCV's..first was a Autozone popular brand starts with "D" and sounds french...lol...benefits of early alzheimers...& second one was a Purolator while in Moab. I noticed when the oil level dropped drastically between fill-ups & my breather cap (filter) was spitting/foaming oil out (normally sucks air in) due to crankcase pressure building up and venting out the wrong end!


P.S.----wasn't going to sleep today if I didn't use the "search" button and fill my alzheimer ridden skull with the name of that PCV sold @ Autozone....(and now it doesn't sound so french) survey say's:

DEUTSCH PCV VALVE for a 2000 ISUZU TRUCK VEHICROSS 4WD

Unit Price: $3.49
Part No.: PCV193
Weight: 0.05 lbs.
Availability: Online: Ships within 2 business days
Store: Normally Stocked