new problem, please look
04-27-13, 10:24 PM
#1
547hp at the flywheel
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new problem, please look
So the car ran great this morning. Went to a local car thing, parked it for an hour. Left to go across the street to eat, and now on the way home the car doesn't feel as powerful. It no longer rips the tires thru 2nd and third like it did before. Boost seems to break up above 10psi. Car dynod 475@19psi at the beginning of the month. Could being at 1/3rd of a tank cause this sort of breakup/lack of power? The aeromotive 340 stealth pump maxes out around 533hp. Im running 22 psi now which should be closer to 500.. could the fuel pump be running out of legs?
Setup: See sig
Things Ive tried: Added a ground to the coil pack bracket, swapped primary coil,
Just doesn't seem like its making the power it was this morning. At this point im tired of thinking about it so tomorrow ill put more fuel in the tank and swap the fuel pump for a bosch 044.
And of course as soon as I finished typing all of this my tuner yelled at me for running less than 1/2 a tank. So my guess is that's the problem.
Setup: See sig
Things Ive tried: Added a ground to the coil pack bracket, swapped primary coil,
Just doesn't seem like its making the power it was this morning. At this point im tired of thinking about it so tomorrow ill put more fuel in the tank and swap the fuel pump for a bosch 044.
And of course as soon as I finished typing all of this my tuner yelled at me for running less than 1/2 a tank. So my guess is that's the problem.
04-28-13, 08:33 AM
#3
547hp at the flywheel
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Compression is good (via piston gauge). Ngk r7520-11 plugs have less than 1k miles on them. 1 has some cracking in the porcelain around the tip tho
04-28-13, 10:04 AM
#5
547hp at the flywheel
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Builds boost ok. Just falls on its face. I'm leaning towards an ignition problem although my wideband says it goes lean when it happens. My head thinks if it was going that lean when it happens I would have grenaded the engine. Meth/water isn't THAT good if a savior.
04-28-13, 10:08 AM
#6
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its either fuel, ignition, or turbo/boost related.
the engine will lose power if you don't have the fuel to keep it going.
What AFR are you seeing when you have this problem?
04-28-13, 10:33 AM
#7
F'n Newbie...
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While breaking in my last engine I ran 3oz/gal premix. My plugs got so fouled they would barely fire, my MTX-L read 16-18 afr. I was essentially dumping raw fuel out my exhaust because the plugs wouldnt fire.
At the very least I'd get rid of the one plug with cracked pocelain.
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04-28-13, 10:42 AM
#8
Racing Rotary Since 1983
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plugs.... "cracking in the porcelain "
you have detonation. detonation breaks porcelain.
of course the question is what was the cause.
more likely fuel rather than ignition. it might relate to an AI failure as well.
howard
you have detonation. detonation breaks porcelain.
of course the question is what was the cause.
more likely fuel rather than ignition. it might relate to an AI failure as well.
howard
04-28-13, 10:56 AM
#9
547hp at the flywheel
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I think I found the issue. The fuel hose that connects the pump to the supply tube in the tank had slipped down to the bottom and was most likely not supplying most if its fuel to the engine and just spraying it in the tank.
Haven't driven it yet but my guess is that's the problem.
Haven't driven it yet but my guess is that's the problem.
04-28-13, 01:20 PM
#12
547hp at the flywheel
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compression is good. 40psi jumps on the piston for all faces. builds to 120. took it out, back to normal. now I just need to dial in the avc-r for solid 22psi at all times and change my sig to 500hp club
04-29-13, 05:49 PM
#15
547hp at the flywheel
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It was most likely the water/meth injection that saved the motor. I didn't "scrimp" on the hose so to speak. Just miscalculated it. This car was reaaaaaaaly messed up before I bought it.
05-01-13, 10:49 AM
#17
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I think I found the issue. The fuel hose that connects the pump to the supply tube in the tank had slipped down to the bottom and was most likely not supplying most if its fuel to the engine and just spraying it in the tank.
Haven't driven it yet but my guess is that's the problem.
Haven't driven it yet but my guess is that's the problem.
make sure you got all that good and check the spark plugs
05-01-13, 02:00 PM
#18
Either way you need new plugs...and not sure why your running 11's all around. you should def take care of that hose. Take this as an instance where you cheated death... could've really blown the motor like that. Time to fix the root problem and thats that whole line as a whole. Don't just re-tighten it.
05-01-13, 02:56 PM
#19
Sounds like he's one lucky bastard! Cracking porcelain is from detonation waving into the plug. I detonated 6 years ago on 3mm OEM seals and they somehow took it just like this instance. Sometimes Jesus blesses these engines...
05-01-13, 03:10 PM
#20
One thing that sucks about aftermarket pumps is having to cut the metal pickup tube and mate it to the pump with pressure hose. My fuel setup looks the same but I made sure to run a hose long all the way up the neck with two clamps!
Good save and lucky bro!
Good save and lucky bro!
05-02-13, 03:31 PM
#21
547hp at the flywheel
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still going on about this? its been repaired for a week :P. ive been building rx7s for 15 years, im not a complete newb. Plugs got replaced (just cant get them locally), fuel line got replaced with one thats probably 8" in length. the savior on this was the seals (its not a stock motor) mixed with the water/meth to limit the damage done. I have no doubt that 1 if not both housings won be reusable on the next rebuild, but thats a problem for another time.
as far as the compression tester, yes the schrader was still in the bottom of it hence the lower readings. i know when ive blown a motor, hell i know when ive weakened one.
as far as the compression tester, yes the schrader was still in the bottom of it hence the lower readings. i know when ive blown a motor, hell i know when ive weakened one.
05-02-13, 09:04 PM
#22
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still going on about this? its been repaired for a week :P. ive been building rx7s for 15 years, im not a complete newb. Plugs got replaced (just cant get them locally), fuel line got replaced with one thats probably 8" in length. the savior on this was the seals (its not a stock motor) mixed with the water/meth to limit the damage done. I have no doubt that 1 if not both housings won be reusable on the next rebuild, but thats a problem for another time.
as far as the compression tester, yes the schrader was still in the bottom of it hence the lower readings. i know when ive blown a motor, hell i know when ive weakened one.
as far as the compression tester, yes the schrader was still in the bottom of it hence the lower readings. i know when ive blown a motor, hell i know when ive weakened one.
05-02-13, 11:59 PM
#23
547hp at the flywheel
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Last week I was tired and figured a post with ideas while I slept wouldn't hurt. Anywhere in my post suggest I'm a master rotary builder? 1/3 of a tank can starve fuel. Properly use a compression tester? Lets look at that statement for a second. If it was proper to use that style to begin with my guess is Mazda wouldn't have made the other style. You wouldn't have to remove anything for it to function properly. It's a tool that CAN be used for a base line. Not the ideal tool. If you don't have anything constructive to add to a post, don't reply. I added my fix so anyone else having an issue that uses the search function can read what I did for my repair. I built my car. Not a shop. Not my buddy. I did. Still runs after some detonation so I'd say I'm doing just fine.
05-03-13, 03:03 AM
#24
Exhaust Manifold Leak
You got lucky!
cracked the rear iron 3 weeks ago due to sucky stock fuel pump wiring (pump saw only 9v). engine had maybe 1000km since rebuilt, luckily no damage to stock 2mm FD seals. also plugs looked fine. lesson I learned..
measure fuel pressure with injectors out of the engine and 100% duty cycle at max boost (=fuel pressure) you want to run, if the fuel pressure remains stable, your good to go.
with the 9v at the pump (AEM 340 lph), pressure dropped over a bar when injectors got over 70% duty
cracked the rear iron 3 weeks ago due to sucky stock fuel pump wiring (pump saw only 9v). engine had maybe 1000km since rebuilt, luckily no damage to stock 2mm FD seals. also plugs looked fine. lesson I learned..
measure fuel pressure with injectors out of the engine and 100% duty cycle at max boost (=fuel pressure) you want to run, if the fuel pressure remains stable, your good to go.
with the 9v at the pump (AEM 340 lph), pressure dropped over a bar when injectors got over 70% duty
