cj donaldson wrote: Just wish to add my 2 cents. Now egr is vacuum operated and so easiest way I could figure was to block the vacuum line. No codes but not sure if it is working. Any feed back is welcome:) cj
you'll want to check the valve is closing and opening completely when connected to vacuum. They often don't because of carbon build up. You can remove it to clean or replace, your choice. if it's open too much, you may have difficulty starting it, or even keeping it running.
no codes YET - is there a freeway/expressway near you that has a long and/or steep downhill grade? drive up to it at speed and then take your foot off the gas to coast down and see what happens.
Greg do you think gutting or changing to high flow cats would have a benefit to mileage gains. As to reduce the parasitic load on the engine. Also how can I tell if the egr is full functional. What are your thoughts on it’s effects upon carbon build up in the inlet manifold and pistons. I would look at it as a means of programmed obsolescence and feel the cleaner the internals the better. This is what attracts me to water injection for decarbonisation and cleaning exhaust gas
There are a few things there and I'd like to address them fully and individually:
restrictive exhaust - an engine is simply an air pump; any restriction on either the input or outlet restricts it's efficiency of turning one type of energy to another. The trick is correctly identifying a restriction, and then applying an appropriate repair. only you can measure pressure differentials when it's running.
This guy focuses on aerodynamics...but you should really call it hydrodynamics, the dynamics of fluids, of which "air" is one. it runs both through as well as over various places of any automobile, including the intake and exhaust. I post this video so you can see there are ways of measuring, and tools to do so. using inches of water versus inches of mercury makes for an instrument to do some very fine tuning indeed:
#allthesmallthings
EGR functioning - since your valve is vacuum actuated (right?), you'd need to apply a vacuum to the control valve from a source other than the intake manifold while the engine is running at hot idle. maybe you have a hand pump for bleeding your brake system, like this:
for electronically controlled EGR valves, you'll have to dig into OBD ECUs and try to determine what triggers/regulates the system. My current vehicle has a MAP sensor; my previous one had a DPFE sensor connected to different ports on an orifice tube (much like the instrument in the video above, come to think of it...) that sent a signal to a solenoid that modulated vacuum to a regulator. I suspect the latter example is the case on your carbed Toyota. Dig into Mr Edgar's video channel and you'll find some tricks/tips/hacks for you to try on your vehicles to help you.
Carbon buildup...well, burning hydrocarbons results in carbon waste. burn less hydrocarbon, have less waste. complete combustion results in water vapour as well, however, so finding and expanding the sweet spots to burn as little hydrocarbon as widely as possible across the range of operation, is the ultimate goal, so that you recycle the water vapour through the system (which you've already proven has a significant effect on efficiency). water will also wash whatever carbon results/remains into a fluid to carry it away - oil and its associated filter.
once again, it's #allthesmallthings. which means you have to approach it holistically, and individually. every vehicle/engine is different.
Cars/engines would last for much longer than they do if our ideas were applied at the factory...but those factories wouldn't have the voluminous output that they do, and people wouldn't have jobs, economies wouldn't work like they do...the planet might be cleaner place, and stressors to us would be different, but I can't say whether life for everyone would be better.
now that I've gotten all philosophical, it's up to you to take things as far as you think is best, CJ. let us know how they're working out for you, would you please?
Greg Kusiak
Most Active Member
Audiophile
The following user(s) said Thank You: Tracy Gallaway, Johnathan, cj donaldson
Quick update. Have done plenty of driving but still no code. I have not refuled yet but the truck seems to be getting better efficiency on the gauge. I am tempted to put a blocking plate on the egr. Also am thinking seriously about gutting my cats as we don’t have emissions compliance checks. I figure once I get my Efiie and map sensor devices I can implement water injection to get the emissions down. I have a feeling by the way the engine performs that the cats are choking it. There is 236000k on the clock and if running rich I guess this could be clogged. The inlet manifold is pretty black with exhaust soot.
No the Toyota is pre cats and egr valves and it it still running great. Talking about my Nissan Pathfinder/terrano 98 3.3v6 is it likely that the comp would throw a code if I gut the cats? I’m not a mechanical engineer but I really don’t see the benefit of catalytic converters. Other then emission control why not get the engine running properly and burn less fuel right instead?
I'm not certain, but I've done enough thinking on this to realize/believe that the rear o2 verifies functioning of the converter: the computer has the data to reckon intake air mass plus added fuel for 14.7:1 then the intake air minus what the combustion event burns for the delivered amount of fuel leaves X amount of oxygen after the cat to balance the equation. If the oxygen levels are off there, you'll probably get a code...and the reaction in the converter is taken into account in the balance equation as well, no doubt - that's proven chemistry.
So yes, I would say to expect a code if you get rid of the catalyst in the converters (I assume that's what you mean by gutting), or replace them with straight pipes unless you've a way to make the computer think there still is one, and it functions under all conditions/circumstances.
The ones I use from Eagle-research.com add a voltage offset to the upstream sensor signal to lean out fuel delivery, so resistance on the downstream sensors wouldn't be of any help as I understand things - you'd just get fuel overdelivery and a catalytic converter error code...unless you were going to use a potentiometer as a voltage divider between +ve and signal wires.
I'm of the opinion that you need to do whatever you can to get it right prior to the cats; groove w/ pcv re-route, ignition (a big one!!!), and then nudge/gently coerce the computer with some sensor signal mods to tighten it all up. in my experience, these will get you 90+ % of the way to the best efficiency the machine in question can achieve, and you'll probably never run into any issue with the cats or their downstream sensors.
Similar to your other thread about the carb'ed toyota, you could add water injection to this engine as well, and I'd wager that you'd get a better mileage/consumption improvement because I assume this engine has a higher compression ratio.
Greg Kusiak
Most Active Member
Audiophile
The following user(s) said Thank You: cj donaldson
