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Changed Plugs...No boost??

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Old 06-26-05, 04:05 AM
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Unhappy Changed Plugs...No boost??

I've had my RX for about 2 weeks or so and have been doing some routine maintenance for reliability. I had been noticing that ive been getting some knock on my PFC and the timing on my leading and trailing plugs were negative degrees. So I changed the plugs to all 9's and now my turbos arent spooling up. I still have negative timing and im not getting any boost at all. I took off my strut tower brace, the inlet pipe to the TB and changed the plugs. The plugs are in tight and the wires are also on tight. Im definetly getting spark but no boost and my timing is still negative. Any ideas??
Old 06-26-05, 04:21 AM
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Since you took off your TB elbow, you probably have a huge boost leak somewhere. Recheck the o-ring on the elbow along with the hose clamp(s). Next time you change your plugs, go from the bottom -- it's ten times easier. Good luck!
Old 06-26-05, 04:32 AM
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You knocked off one of your vacuum hoses, dont worry, just take a look around the area that you were working on and plug it back. Checl MAP sensor first
Old 06-26-05, 04:33 AM
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Wires on correct?

Yeah what WaLien said...
Old 06-26-05, 04:38 AM
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I checked and double checked the vaccum hoses, and made sure the elbow was on correctly and the o-ring was free of debris. My turbos arent even spooling up at all. I let the car warm up the gave it some gas and there is no response from the turbos at all. I will recheck all my hoses and re tighten the elbow here pretty soon. And I checked the boost sensor first because I know this is a common problem.
Old 06-26-05, 05:39 PM
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Ok so I went to look at the elbow and my vaaccum lines and one of the nuts that attached the elbow to the TB is stripped. Anyone got any suggestions on how to get the nut of. Oh and my turbos still dont spool up at all. The car starts fine but when i give it some gas there is still no respnose from the turbos. Even if there is a boost leak I should still be able to hear them spool up correct??
Old 06-26-05, 06:08 PM
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are you sure you have a boost leak or is it that you bumped something when taking of the TB and all those hoses and accidently hit the vacuum line for the boost gauge so now the boost gauge reads zero but in fact you are getting boost??? Drive it around the block a few times just to see if it feels any different from before.
Old 06-26-05, 06:11 PM
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Originally Posted by FormulaRX
are you sure you have a boost leak or is it that you bumped something when taking of the TB and all those hoses and accidently hit the vacuum line for the boost gauge so now the boost gauge reads zero but in fact you are getting boost??? Drive it around the block a few times just to see if it feels any different from before.

good point however if he knocked the boost gauge line off, that he wont be able to read vaccum too correct? that right there is a giveaway if its the boost gauge line or not..
Old 06-26-05, 06:35 PM
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ok guys, the boost gage is connected properly. at idle i see 15" of vaccum. when i give it gas past 3000rpm the vaccum increases to about 20-25". The turbos are not spooling up at all, hints why im not getting any boost. I tried to re-check my vaccum lines but I dont see anything out of place and no hoses disconnected. I would take my elbow off but one of the nuts is stripped and that is further blocking my view. Even if I wasnt getting boost on my boost gage I should still be able to hear the turbos spooling up and they arent. Any other suggestions??
Old 06-26-05, 06:39 PM
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when you hit the throttle, your vacuum is supposed to head towards 0, not go backwards..

example: idle at 15, blip the throttle a bit and watch the needle jump to 5 or something..

def sounds like a vacuum leak, i would check, double and triple check everywhere you were working on in the engine bay..
Old 06-26-05, 06:44 PM
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LOL, yeah i understand what my vaccum is supposed to do and that is exactly my problem. I will check the area again but will a vaccum leak cause the turbos not to spool up at all??
Old 06-26-05, 07:34 PM
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Ignoring the boost gauge, can you hear the turbos spooling whine?

There are lots of things that can cause lack of boost. A vac leak is one of them and there are plenty of places for that to happen.

It could be something unrelated to your plug change. Better start reading up on the turbo control system. Search for boost and turbo troubleshooting.
Old 06-26-05, 07:34 PM
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^^yes and no

it depends i think but ill let the veterans come in and verify this..

i remember when i was changing my IC couplings, one of them were loose and i lost about 4psi of boost due to this..i tightened the coupling and i got all my boost back so ill say yeah and no..depends on how big the leak is..
Old 06-26-05, 07:51 PM
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i dont think a boost leak would stop the turbos from spooling, i would recommend checking the turbos, you may have knocked something off it or something.
Old 06-26-05, 08:04 PM
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Put you car on jack stands or a ramp and check to see if the wastegate actuator is free to move. Then start to trace backwards to the wastegate control solenoid.
Old 06-26-05, 10:59 PM
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Finally the type of answer i was looking for! No offense to you other guys.
Old 06-26-05, 11:56 PM
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Maybe this doesn't apply here, but could it be something with the double throttle warmup? I take it he changed the plugs when it was cold. Perhaps he fired it up and started reving it right away. Doesnt that car have to get up to an acceptable temperature until it will boost enough to notice?
Old 06-27-05, 12:10 AM
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so did you figure it out yet???
Old 06-27-05, 12:41 AM
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No I didnt figure it out yet. I have the SMIC and the intake off right now and will troubleshoot the turbo control system tommorow. Is it safe to drive the car with all of that stuff removed. It will just be getting air directly to the throttlebody so I dont see why. I have to take it to the auto hobby shop we have here to get use of some jackstands. I changed the plugs because my timing was changing and due to my lack of knowledge of the PFC i took that as bad indications. The trailing plug in the rear housing was tan and the rest were black and pretty corroded. The car will start up just fine but my ignition timiing when warm is ign leading(-5) and ign trailing(-20). Im still pretty new to the PFC and am trying to learn. I dont yet have a datalogit or a wideband and those are next on my list of things to do after some rear tires and a better radiator. Although this is kinda shitty its pretty fun taking the car apart for the first time and looks like it will be a really good learning experience. Oh and I will be sure to post some pics later of the car.
Old 06-27-05, 06:14 AM
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did you check to make sure you put the plug wires back on correctly like they mentioned before, mainly the 2 trailing plugs since they both hang from the middle and can get mixed up easily. What does the car do when you blip the throttle of try to rev it up some?

Tim
Old 06-27-05, 07:59 AM
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First, I don't know ignition and PFC, so I can just suggest a few things for that. But IMO fixing the turbos isn't as important as getting your tuning correct. I would start by changing plug wires as well, and doing the basic checks on the ignition coils. Finally, be sure the PFC settings are set properly. Does the PFC have a limp mode that prevents boost when ignition/knock is detected? Can you swap the stock ECU to check for codes?

As for driving with the intercooler/tb elbow disconnected - I've done it, but only idling in the garage. I would put some sort of mesh very well secured over the end of the TB elbow if I was going anywhere.

Anyway, when you're sure you're done troubleshooting the ignition/timing/tuning, then worry about the turbos.

Turbos: First, I recommend buying a Mityvac Silverline Plus vac/pressure kit. This thing is helpful for bleeding brakes and clutches, and especiallly good for checking turbo control parts. Also keep some long-reach needle nose pliers handy. I bought cheap ones from harbor freight tools and ground the knurling and sharp edges off the 90° bent-nose pair. This little tool is a lifesaver for working with the vacuum hoses.

Start with the basics; after running the car at idle, pull off the hose at the vacuum chamber, or any of the hoses leading directly from the chamber. You should get a solid rush of air for a couple seconds. Repeat the test, but this time cut the engine and wait 5-10min to see if there is slow leakage. If you have a Mityvac, tee it into this location and verify that it creates and holds 25inHg (your maximum vacuum).

Do the same for the pressure tank, using the Mityvac if available. However, if the primary isn't spooling, the pressure tank isn't important yet - it's strictly a supplement for the secondary operation.

Perform the KOKO test (http://www.fd3s.net/boost_test.html). Both actuators should move in at key off, and out on key on. If you're not able to generate above 0psi with the rev in neutral, then the CCA will move but the TCA probably will not.

Check the ABV with the Mityvac, and disconnect it from the airbox. It should not make noise when you're on the throttle.

Dave

Last edited by dgeesaman; 06-27-05 at 08:11 AM.
Old 06-27-05, 11:58 AM
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You More That Likely Have Left Something Disconnected, You Just Need To Retrace Your Steps...
Old 06-27-05, 08:31 PM
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Thanks for the help guys. I will keep you posted on hwo everything goes. Anyone else got any suggestions.
Old 06-28-05, 01:35 AM
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Thumbs up Some good out of the bad

Well since I have the whole top half of the engine apart I am going to remove the airpump(i have a midpipe) and try and remove some of the non-essential solenoids from the rats nest. I am very new to rotary engines and once I took the UIM off I was pretty shocked at how complicated everything looks.. I am getting a FSM here pretty soon so I know how to put everything back together.

Current Mods
mild streetport
PFS full race exhaust
PFS SMIC
Pettit intake
Power FC

Things goin in very soon
Either a Jacobs or a Twin power(any suggestions?)
Pulley kit
new ignition wires
new ignition coils
rx7 fashion intake
supra fuel pump
new fuel filter
wideband and display
datalogit
y-pipe and crossover pipe
and then it time for a tune!

Im guessing the car will probably be down for a month or so. Wish me luck!
Old 06-28-05, 04:47 AM
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Bad way to cure the car. First fix it, then do more work or you'll never or hardly come to the core of the current problem as more will arise.

Just my $0.02


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