which IM for 3.0?

[SicSE]

unless you dump enough fuel to dilute the oil and then ruin your cylinder walls because your oil is contaminated with fuel and doesnt lubricate

Which is most easily prevented by keeping the PCM, injectors & MAFS matched.

An interesting side note... the new 6.4L diesels are having this problem a lot. Funny those high-paid engineers didn't foresee this problem with injecting fuel on the exhaust stroke.

 

[KAOS_3.0]

granted about washing the rings, thats why I'm looking to ghetto rig the ait so it'll run not-so rich untill joey can tune it. I only have to save 100 bucks, thats not a big deal

might run untuned for a month or two max (and only because I'm broke and janky)

I'm also trying to save up for a diff too, and struts, so I've got a lot to get together with very little money.

what do you think is worse, 200+ chp on a 99 glass diff, or running a little rich with a ghetto iat hack?

 

[turbo_fox]

granted about washing the rings, thats why I'm looking to ghetto rig the ait so it'll run not-so rich untill joey can tune it. I only have to save 100 bucks, thats not a big deal

might run untuned for a month or two max (and only because I'm broke and janky)

I'm also trying to save up for a diff too, and struts, so I've got a lot to get together with very little money.

what do you think is worse, 200+ chp on a 99 glass diff, or running a little rich with a ghetto iat hack?

i wouldn't run it. As SicSE has already stated, you can run it on the 17 lbers. thats probably what I would do. I def wouldnt run it with the hack. Check out how my engine looked after running for 10 minutes at idle with a messed up MAF/injector calibration:
keep in mind it had only 10k miles on it.

as for the dif, i am still running a stock dif in my 3L. it has 3 autocrosses on it, too. you only need to worry if you drive like a meat head.

 

[KAOS_3.0]

I drive like a meathead

it will literally be hard for me to drive it like a normal person, I barely know how. I snapped the center shaft in a cut gear diff with the old raggedy 2.5.

more power, weaker diff, not good at all.

at any rate, the injectors are not changing, I'm not hacking the harness up again, only to hack it up a third time when I'm ready for my tune, thats just retarded.

so does anybody have a chart for the duty cycles for the injectors at varied inlet temperatures? that plus the chart listed earlier here will give me the info needed to properly reduce the duty cycle by 40% via a iat trick.

 

[turbo_fox]

just be careful. the chain of events for mine was blown headgasket due to lean (30 lb/hr injectors), new headgasket, larger (60's) injectors, and a tune, the tuner thought my maf was a lightning and it wasn't, which led to the failure.

heres what the engine looked like before it ran with bad tune, just incase you thought maybe it was beat already:

 

[KAOS_3.0]

yeah, but thats on a boosted engine

what maf were you running besides a lightening?

 

[turbo_fox]

yeah, but thats on a boosted engine

what maf were you running besides a lightening?

re-read. it ran at idle for 10 minutes. being boosted has nothing to do with it. the damage came idling in the driveway. i never even drove the car. my point was it had 60 lb/hr injectors and a MAF calibrated for 30 lb/hr. The tuner changed the function thinking the meter was a lightning, so a 42 lb/hr maf, the tuner thought he needed 30% less fuel (meter 42, injectors 60) when in reality he needed to pull 50% (30/60).

it was a ford racing 30 lb/hr meter, old skool from before the lightning was even built.

 

[KAOS_3.0]

ahh, thats pretty sever damage for only 10% more rich than the 24s will be

at any rate though, though it may not be perfect, and the mapping will fall on it's face at times, using a resistor to jack-leg the IAT into believing it is much hotter outside should prevent those kinds of rich levels.

 

[SicSE]

so does anybody have a chart for the duty cycles for the injectors at varied inlet temperatures?

There is no such chart because the PCM also considers input from many other sensors when calculating fuel.

 

[KAOS_3.0]

damn, yeah, thats why I was saying the engine maps will fall flat on their face all over the place this way too, because it'll be getting some odd readings and the IAT maps will be calculating for a much less dense air charge, but at least it shouldn't blow up untill I get a tune.

so would you say a 40% increase in IAT temp signal would be a good place to start?

 

[KAOS_3.0]

just quoting this to get it back up to the current part of the thread

[edit] so based on that, I should need a 24Kohm resistor to read a little more than 40% hotter at 50 degrees? (average temperature here in the winter)

or better yet, I guess I need to look up the density of air at different temperatures, then calculate how much hotter air would have to be to have 40% less oxygen in it, that sounds better to me actually.

 

[KAOS_3.0]

so I was able to find this, I'm guessing it's reasonable to assume the stoiciometry of "air" remains fairly constant over various temperatures, right?

so I only need the engine to believe it's running on an air charge 40% less dense than it really is?

 

[KAOS_3.0]

I did some mathes, this is what I got, appears my initial guess of wanting it to believe it's 200 outside was an understatement.

1.293 + 1.205 = 2.498
2.498 / 2 = 1.249 (air density at 10*c, or 50*F, the average ambient temp here in winter)
1.249 - 40% = 0.7494 (desired air density reading from IAT)
Which looks fairly close to the density at 200*c, so it would appear by this means of determining the desired resistance from the IAT, we need it to be the lowest possible before the EEC believes it is a short, which if the chart provided is correct, would be 1.18K ohm, providing 0.27 of voltage to the EEC for calculation.
That would be telling it the air density is 0.898, which is 19.829% more dense than we’re looking for, but still means the engine would only be running about 20% rich rather than 40%.
Not good for performance or fuel economy, but should be good enough to keep it from self destructing immediately, right?

[edit] that would be equivalent to 20.4 lb/hr injectors, which is only 7.368% richer than SVT injectors, which supposedly run fine on an se pcm, correct?

 

[KAOS_3.0]

so it looks like this 1K (brown black red) resistor I have should do the trick, if it's not too little resistance for the EEC to recognize as not a short.

 

[Pudmunkie]

:help:

 

[KAOS_3.0]

is that what your offering, help?

because your more than welcome to send joey 100 dollars for my tune and save me and my engine all this drama if you'd like

right now this is what I'm doing to just get it running so I can get to work by means other than a bicycle in 40 degree weather.

 

[TheMexicanJob]

40 degree, that's it? i was still riding to classes and all over when it was well into the 20's and 30's

 

[KAOS_3.0]

damn, thats cold for a mexican!

 

[turbo_fox]

this looks like it won't end well. what if you are incorrect in the pcm strategy, are you 100% certain it works the way you are saying? this seems like a pretty daring method. i wouldn't be doing it. if you really need to drive the car, then put the 17 lbers back in. that is by far the safest solution.

 

[Pudmunkie]

I don't understand what the big deal is; use an SVT PCM or get a tune. You should have considered all of this before you tried to run with the big dogs and roll around in a 3 liter. If you can't afford the 100 dollars joey wants for a tune you shouldn't be doing anything but putting a 2.5 liter back in the car stock as stock can be.