Fuel consumption seems high
#16
#17
These new NGK's were running great with the new 4 hole injectors. It never sounded better before the HG went. (the engine was also running nice and cool with these, though the plastic covers being discarded played a role)
Last edited by tv; 03-24-2022 at 02:48 PM.
#18
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Joined: May 2008
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From: 2706 Skyline Drive, Grand Junction CO 81506
As to the gas consumption I suspect that you are missing a very likely culprit. You need to check that your Fuel Pressure Regulator and the Damper(s) have not failed in that the vacuum diaphragm in one or more of them has ruptured thereby allowing fuel to be sucked into the intake where the vacuum is created to operate them. I think that could also affect your idle.
I think also that there is likely some misunderstanding about the heat range for Spark Plugs. None of that has anything to do with the heat of the spark being produced, but rather the amount of heat that is allowed to build up in the body of the plug for the purpose of fording off plug fouling.
I think also that there is likely some misunderstanding about the heat range for Spark Plugs. None of that has anything to do with the heat of the spark being produced, but rather the amount of heat that is allowed to build up in the body of the plug for the purpose of fording off plug fouling.
#19
As to the gas consumption I suspect that you are missing a very likely culprit. You need to check that your Fuel Pressure Regulator and the Damper(s) have not failed in that the vacuum diaphragm in one or more of them has ruptured thereby allowing fuel to be sucked into the intake where the vacuum is created to operate them. I think that could also affect your idle.
I took a moment to remove the MAF and turned this screw 1/8th counter clock wise as instructed by @Rob Edwards. Gotta see how the gas burning goes like this. I'm not expecting miracles but I prefer to run my engines a little lean. Here's my MAF.
#20
Sometimes the pot is adjusted to compensate for vacuum leaks; I am guilty of this behavior. If that has been done and the leak(s) get fixed; like when an intake refresh is done; the MAF would most likely run the car over-rich; too much can prevent the O2 from correcting enough/quickly enough to compensate adequately.
We want to know what the MAF setting is currently sitting at. Check it using ohms.
Take the multimeter and attach to terminal numbers 6 and either 3 or 4 on the MAF itself if it's still out of car (alligator clips work well for me) or if the MAF is installed disconnect the LH connector and attach to pins 14 and 25 (ground) - 14 and 25 are both are on driver's side of double row of connectors; 14 is at very top, 25 is the bottom one. Mid point for the MAF ohms setting is 380. Give us the data...must have data. We love the data.
As an FYI and a personal recommendation for tuning purposes its obviously faster to check MAF setting through the LH; I got some junior timer connectors and made a set of wires to plug onto the LH terminals. I have used alligator clips before I made my test kit.
We want to know what the MAF setting is currently sitting at. Check it using ohms.
Take the multimeter and attach to terminal numbers 6 and either 3 or 4 on the MAF itself if it's still out of car (alligator clips work well for me) or if the MAF is installed disconnect the LH connector and attach to pins 14 and 25 (ground) - 14 and 25 are both are on driver's side of double row of connectors; 14 is at very top, 25 is the bottom one. Mid point for the MAF ohms setting is 380. Give us the data...must have data. We love the data.
As an FYI and a personal recommendation for tuning purposes its obviously faster to check MAF setting through the LH; I got some junior timer connectors and made a set of wires to plug onto the LH terminals. I have used alligator clips before I made my test kit.
Last edited by 928NOOBIE; 03-25-2022 at 08:48 PM.
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dukenukemx (03-25-2022)
#21
As to the gas consumption I suspect that you are missing a very likely culprit. You need to check that your Fuel Pressure Regulator and the Damper(s) have not failed in that the vacuum diaphragm in one or more of them has ruptured thereby allowing fuel to be sucked into the intake where the vacuum is created to operate them. I think that could also affect your idle.
But there is quite a bit more to that story, which I've been trying to get people to understand:
Long before the diaphragm in the stock fuel pressure dampers fails and dumps fuel into the intake system (which means the diaphragm has to actually crack and leak), the diaphragms have gotten rock hard and no longer move, which is required for them to do their job.
The result is there are significant fuel pressure surges in the fuel rails (which the dampers are supposed to control.)
This creates both rich and lean areas in the rpm range, depending on what the pressure surge is doing.
The O2 sensor attempts to "chase" the fuel mixture, but the pressure surges occur way faster than the O2 sensor can respond....or even show the issue.
The point is:
The fuel injection system is a....system.
The individual pieces are all dependent on each other.
Trying to tune the fuel injection system, which can't function correctly because of bad parts, is a fool's errand.
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Darklands (03-26-2022),
dukenukemx (03-26-2022)
#23
#24
Thanks Greg,
the next time on the Dyno I should measure air fuel ratio.
Without hard data I think is leaning these engines with the dump computer’s dangerous.
the next time on the Dyno I should measure air fuel ratio.
Without hard data I think is leaning these engines with the dump computer’s dangerous.
Last edited by Darklands; 03-26-2022 at 05:43 PM.
#25
For this reason, "generic" chips are a terrible idea.
One of my mentors, who taught me a bunch (in my youth) used to have a great saying about running lean and running the ignition timing right on the "edge" (on a drag race boat.)
"You really aren't making optimum horsepower, unless the inside of your exhaust pipes are metal sprayed with aluminum, from the pistons, after every run."
He also never ran a tachometer in any of his boats:
"If you're behind, you need to go as hard as possible. A tachometer is only going to make you "lift" off the throttle, and slow you down."
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Darklands (03-29-2022)