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Leaking primary injectors- What to do?

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Old 04-21-08, 10:25 AM
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Leaking primary injectors- What to do?

This sounds like a very basic question, but I've not really had to deal with my fuel system other than a new fuel pump before.

I'm looking at a TII that has leaking primary injectors. I would just like to know 2 things.

First off, could leaking primary injectors cause a low compression reading, which would be fixed by solving the injectors problem?

Secondly, with leaking injectors, do I just buy new injectors and install them, or is there more to it? How much $$$ should I have set aside to take on this job? And is it something I could reasonably expect to do in an hour or two in the previous owner's driveway, and drive the car home?

I've searched the first page and a half of results, and didn't find anything that appeared to be directly related. Thanks for any input and help on this matter!
Old 04-21-08, 10:45 AM
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not a drifter

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i dont see how leaking injectors would affect compression, it could make the car a bitch to start and keep running though. send them off to get cleaned and flow tested, and get new orings for them. all in all should cost about $100 and a week of your time. should take about 30 mins to replace them if the car is stock and the motor is all together.
Old 04-21-08, 10:59 AM
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so you got pistons oh wow

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the only reason that leaky injectors could cause some kind of bad compression numbers could be that the leaking gas is wiping off the oil coating on the housing so it wont seal as good but IMO it has to be a pretty decent leak on the injector for it to mess up the compression on the engine. the way i would verify that would be pouring a little 2 cycle oil in by the sparkplugs holes, pull out the EGI fuse, crank it a little to try to create a new coating on it and then do another compression test and that would be more accurate. as for the other note. to replace the primary injectors you need to remove the UIM with the TB all together and it would be a great chance all the vaccum hoses, Fuel lines, that evil little coolant hose that goes from the rear Iron to the UIM and whatever other messed up stuff you find on it, Injector Plugs, Injector Orings, mid manifold gasket, ect, ect, ect. it is fairly easy if you have any kind of mechanical inclination!!!
Old 04-21-08, 11:57 AM
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Thanks for the information, guys. The seller claims the car has 5k on a Mazda reman... I would've thought that they would cover whatever went wrong with it. It also seems the guy may be less-than-forthright about the poor compression, as you've rather well confirmed my fears that compression would not read low simply because of leaky injectors.
Old 04-21-08, 01:25 PM
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so you got pistons oh wow

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If I'm not mistaken and someone please correct me if I'm wrong Mazda would only cover stuff on the actual block unless they did the whole swap. or it would have had to be installed by a certified shop to maintain warranty. if the guy just purchased the block and did the swap himself it wont be covered. dont want to get your thread out of subject but i have a TII I'm selling just in case you could be interested
Old 04-21-08, 02:19 PM
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Polito, thanks for letting me know. I think it's totally in the interest of why I posted this thread in the first place- that is, helping me obtain a TII. It looks like you're also a semi-reasonable distance away... Link to your TII for sale thread?
Old 04-21-08, 02:38 PM
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so you got pistons oh wow

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here it is.

https://www.rx7club.com/showthread.php?t=748279
Old 04-21-08, 05:44 PM
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I'm the guy who's selling the car. The motor is stock, no porting, etc. turbo is also stock, the secondary injectors are 750's due to running the Rtek 2.0 ecu. I checked the compression in both the front and the rear. Front was fine, the rear was on the low side, however, the car will start up, and once its warm, it will idle at 900 RPM's. In lower rpms, its flooding a bit, and in higher rpm's or when i took it on the hightways over 50 mph, it smoothed right out and there wasn't a noticeable difference. I checked the apex seals and the springs to make sure nothing was wrong. the motor does have only 5K miles on it, it was rebuilt by a dealership in binghamton, NY....this was prior to me buying the car from its owner. The owner is a good friend of one of my good friends, so i knew everything about the car before i purchased it. The only thing i had done was a dyno tune at KDR Performance of my Rtek ecu. other than that, oil changes and that's it.

Now, if someone on here has any other ideas other than the injectors, let me know, and i can bring it back in the shop and fix it before its sold. I'd rather have it running 100% before i sell it.

-Mike
Old 04-21-08, 05:55 PM
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what fuel pump? do you have an aftermarket fpr?
Old 04-21-08, 06:50 PM
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so you got pistons oh wow

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not to say anything bad about your car but IMO if the compresion would be bad because of the secondary injectors leaking gas the compression would be bad on both rotors not in only one and like i said before it would have to be a big leak to wash off the oil coating on the housings to show a significant loss of compression. i would take it back to whoever built it assuming it still had any kind of warranty to check it out. and also i would take it back to the tunner. if the car was tuned then there shouldnt be any problems with the injectors pushing to much gas thats the one of the points of tunning making sure that youre getting the correct amount of fuel. thats just my two cents. please keep us posted on the outcome of this situation. Good Luck.
Old 04-21-08, 10:29 PM
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So the problem is that it idles too high? You say it's flooding "a bit." Did you adjust the cranking map on the Rtek (it's in the 2.1 anyway) ? Hot start problems are common on Turbo II's, even ones that are running ok.
Old 04-22-08, 07:53 PM
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Ok OBVIOUSLY people do NOT read before they post
1) there is no hot start issue at all
2) the car does NOT idle extremely high, before warmed up its at 600, after warm is 850-900
3) i dont remember saying anything about either a fuel pump OR fpr. Stock pump...stock FPR
4) the ecu is an RTEK 2.0, not the newer 2.1

I was trying to get some feedback to help, not people saying i'm "less-than-forthright" about the compression, i stated when i tested the compression that the rear's compression was not up to standard. If anyone would like to come test the compression and see for themselves, feel free...PM me if you are interested
Old 04-22-08, 08:00 PM
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nah leaking injectors will not cause a low compression reading...

And no you just don't throw those injectors away for new one's...
1.take the old one's out
2.strip them clean by removing all garmets and rubbers on them
3.send them out to be tested and flowed
4.buy new garmets
5.slap the **** together
6.and your golden...
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