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RX7 Ebgine/Boost problems, any advice?

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Old 11-01-09, 12:49 AM
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Unhappy RX7 Ebgine/Boost problems, any advice?

So i own a 93 mazda rx7, bone stock, just over 100,000 km's and just recently have been noticing a few problems.

1: On start up lots of white smoke
2: Only 5 lbs of boost on primary turbo and 10 lbs on secondary
3: Troubles starting up, exhaust smells like gas and seems like its flooding itself
4: when running at idle heat which seems to be gas fumes seep out the top of the engine ...which i'am a bit concerned about

So what im trying to say is, im not hitting full boost on my primary turbo, idles a bit rough now, seems to be running rich. anyone have ideas of what i should be looking for? at first i thought i had a boost leak somewhere cuz i noticed what sounds like a vacuum leak deep down in the engine. i did somewhat of a compression check on my engine and it seems to be good. but now i have this start-up problem... I'm still a baby in the rx7 world and i would appreciate any advice.
Old 11-01-09, 04:01 AM
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Originally Posted by Lepprykaun
So i own a 93 mazda rx7, bone stock, just over 100,000 km's and just recently have been noticing a few problems.

1: On start up lots of white smoke
2: Only 5 lbs of boost on primary turbo and 10 lbs on secondary
3: Troubles starting up, exhaust smells like gas and seems like its flooding itself
4: when running at idle heat which seems to be gas fumes seep out the top of the engine ...which i'am a bit concerned about

So what im trying to say is, im not hitting full boost on my primary turbo, idles a bit rough now, seems to be running rich. anyone have ideas of what i should be looking for? at first i thought i had a boost leak somewhere cuz i noticed what sounds like a vacuum leak deep down in the engine. i did somewhat of a compression check on my engine and it seems to be good. but now i have this start-up problem... I'm still a baby in the rx7 world and i would appreciate any advice.

1: if there is white smoke.. could be that your coolant seals are starting to fail..
(how long does it smoke when started??)
2: could be that either your seloniods are broken, dead, cracked/bad vacc lines...
3: do a compression test.. check spark plugs for any coolant on it..
4:could be that the PULSATION DAMPER is leaking or your one of your fuel lines is leaking..

what were the compression numbers?
Old 11-01-09, 08:34 PM
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well it smokes on start up but when its at operating temperature it only smokes a little bit, i checked my spark plugs and there are no signs of coolant and my oil is good. i wouldn't be surprised if it had something to do with my vac lines, i replaced a good 6 lines that were cracked about a month ago but i know theres more that i can't get too due to my lack of tools :P Pulsation damper? lol, i'm not even sure what that is but from what i've heard it has something to do with my turbo? and it controls pulsations and air flow coming from my turbo?... i dunno but i'll definitely look into it.. and i'll look for cracked fuel lines as well. Um and by somewhat of a compression check i meant that i cranked it with the lead spark plug out just to see if i'm getting a steady "compression sound". i was curious just to see if my apex seals were still good cuz she has over 100,000 km's on it and i don't know how well maintained she was in the past. All i want is to take care of this car best i can and advice from the gurus definitely helps. Thanks for replying
Old 11-01-09, 09:17 PM
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Your pulsation dampener is on the end of your fuel rail and it holds the line on.

it's purpose is to prevent spikes in fuel pressure.

as for the turbo boosting 5lbs sounds like you have a boost leak. may be the turbo it's self.

compression check should explain a lot.
Old 11-02-09, 07:11 PM
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ooh okay, cool thanks guys
Old 11-03-09, 04:10 PM
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I recommend you pull the UIM and pressurize the fuel rail to inspect for leaks. You just need to use the diagnostic box (between the battery and drv side wheel well) and jumper the F/P and Gnd connections, then turn the key in the ignition to the on position. This will run fuel without starting the engine. Look for leaks at the injectors, fuel lines, and pulsation damper.

It's premature to guess at causes but a bad injector could cause most of these symptoms. However FDs rarely have just one thing to be fixed.

Take possible fuel leaks very seriously. FDs have a cast iron exhaust manifold that will light up a fuel leak and make your hood into a puddle of molten aluminum, among other things.

Dave
Old 01-19-11, 01:56 PM
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rx7 not boosting.

hello guys

i recently imported a 95 fd from japan with 51000km, first when i got this car it wasn't boosting past 5000 rmp because the intercooler pipeing was out. i fixed that. now i have bigger problems,

my car at start up doesn't hold up the rev a 2000rmp for more that 1 sec, a friend of mine does so i know its not normal, my rev suddenly drops n stays about 1100 rmp. when its hot its about 750rmp and any this in touch electrical the rev goes down. sometimes it give a problem to start after a hard run, i have to be holding the key for a very long time for it to start, but it always starts, after fixing the intercooler piping, the car still wasn't boosting properly it always had a miss, i've changed my plugs fuel filter.

now recently whilst driving saturday, the car all of a sudden jus bogged didn't cut off its jus that everytime i accelerate its like its getting sum sort of fuel cut, i did chek my fuel pressure its a 30psi

i tried using the diagnostic tool but i found no code. i did so manually using a multimeter i got code 11 and 12, i reset the ecu and drove the car for a few mins its still bogged and when i tried getting those codes again, i found no coded.

when my lights are on in the car and i press brakes everything goes dimmer also affects my dvd player, i did try grounding the vehicle, same problem. right now i can't drive because everyting i accelerate its like the ecu is protecting the car. could it be a bad sensor. i've already ordered the intake air temp sensor and tested my tps which i am getting the voltages from the tps fine. could it be bad grounding.

any help would be appreciated
Old 01-19-11, 06:32 PM
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Originally Posted by mlovence
hello guys

i recently imported a 95 fd from japan with 51000km, first when i got this car it wasn't boosting past 5000 rmp because the intercooler pipeing was out. i fixed that. now i have bigger problems,

my car at start up doesn't hold up the rev a 2000rmp for more that 1 sec, a friend of mine does so i know its not normal, my rev suddenly drops n stays about 1100 rmp. when its hot its about 750rmp and any this in touch electrical the rev goes down.
That's just the difference that his car has an Accelerated Warmup System and your does not. If I had to choose (and I have chosen) it's better to not have AWS. That revving doesn't help anything.

sometimes it give a problem to start after a hard run, i have to be holding the key for a very long time for it to start, but it always starts, after fixing the intercooler piping, the car still wasn't boosting properly it always had a miss, i've changed my plugs fuel filter.
Many possibilities. You've covered some of them.

1) Check the MAP sensor, it's mounted to the firewall right beside the TPS sensor. If there is any MAP sensor issue the car will run in limp mode and act really badly.

2) Do you have a boost gauge? If not I recommend you install one. Determine the max boost and see if you can find the boost pattern. (Boost pattern is covered in the 3rd gen FAQ)


now recently whilst driving saturday, the car all of a sudden jus bogged didn't cut off its jus that everytime i accelerate its like its getting sum sort of fuel cut, i did chek my fuel pressure its a 30psi

i tried using the diagnostic tool but i found no code. i did so manually using a multimeter i got code 11 and 12, i reset the ecu and drove the car for a few mins its still bogged and when i tried getting those codes again, i found no coded.

when my lights are on in the car and i press brakes everything goes dimmer also affects my dvd player, i did try grounding the vehicle, same problem. right now i can't drive because everyting i accelerate its like the ecu is protecting the car. could it be a bad sensor. i've already ordered the intake air temp sensor and tested my tps which i am getting the voltages from the tps fine. could it be bad grounding.

any help would be appreciated
I'm a little too lazy to look up those codes but those are very important. If you haven't already I suggest you buy a Mazda Factory Service Manual or download one from the links in the 3rd Gen sticky threads. The FSM contains step-by-step troubleshooting for each of those codes.

David
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