VivaLaMikey

Hey guys wondering if anyone can help me figure the cause of my boost problems i have tried nearly everything i know of but then i dont know a great deal about fixing problems on a 13btt, so any help will be greatly appreciated as my engine builder is just not returning calls or anything, i have no where else to turn to. I live in Nelson, New Zealand and its a really small town and country we're kinda limited to the help we can get.
So here we go.

Number 1: When im driving round normally at cruising speed 50kmph it seems to run quite nice (apart from my screwed tps giving me the other small problems) but as soon as i put my foot down and if i do it too fast it bogs down and only runs 1psi it feels sort of like somethings restricting it, BUT if i ease on the throttle slowly my air pump will make a weird burping sound and it will have a surge of power and as long as i dont push too hard on the throttle it will run 6psi but no more i just purchased a brand new black box (vacuum solenoid box) for my series 7 13btt seeing as thats what my engine builder seemed to think was the problem but these are still the same issues i had before i swapped, anything i could be missing?

Number 2: I also have a few small problems like backfires, bucking, rev sticking i think these are due to my tps (are they?) and was wondering if that had anything to do with my boost problems?

Number 3: I mentioned before about my air pump (well i presume its my air pump) makes a weird burping/sucking noise when my little bit of boost kicks in and it also does it when im on WOT then change gear, it burps at the same time if not a little earlier than my BOV, and sometimes it will just do it at random times, now i am on my 3rd air pump as i presumed my ones were screwed but after 3 of them its getting a little silly.

Any help would be greatly appreciated.

By the way its only done 5000km on a fresh rebuild with 3mm race seals and mostly all brand new hoses, series 8 turbo's, apexi twin filters, blitz bov, 2.5" exhaust system, brand spankin vacuum box.

Dudemaaanownsanrx7

iTrader: (23)

have you checked your map sensor/hose? does it idle really rich or anything?

gracer7-rx7

iTrader: (16)

Regarding #2, go to the FAQ thread stickied in this forum and look for the thread on adjusting the TPS. I believe is in the Archives sub forum in this section. It isn't terribly difficult but does require some patience. Also verify your throttle body mechanical settings to ensure that they aren't screwy.

Regarding #3, I'd suggest unplugging it to see if the noise goes away. The plug is right on top of the air pump. If it does not go away, I'd be tempted to get a shorter belt running the alternator and water pump temporarily to verify if the noise truly is the air pump. Or perhaps record some video and upload to give us a better idea of the sounds it is making. The air pump normally disengages via a clutch over 3000 RPM iirc. If the sound doesn't go away, then its not your airpump and potentially something related to your turbos.

Regarding #1, Your symptoms sound a bit out of ordinary. I'd suggest tackling 1 & 2 first and reporting back. The FAQ thread has a link to a very good source for turbo troubleshooting. Start there after tackling the first 2 items. No point in repeating the contents of that troubleshooting site in this thread...

Good luck.

VivaLaMikey

sweet will try get those smaller problems out of the way and will work on getting a video or sound recording of the noise.

Dudemaaanownsanrx7

iTrader: (23)

maybe the cat is clogged.. that would explain why you arent getting any power and it feels restricted, and also would explain the airpump noises not being able to pump air in.

VivaLaMikey

this might sound stupid but i dont know alot about rx7's i know a bit but not everything you see my 7 is a japanese import into new zealand and i think i may have read somewhere that jap and nz dont have cat's due to different emmisions law's correct me if im wrong. and yes it does run rich thats all i can smell when im idling at a set of lights or at a drive thru.
something i forgot to mention is that it went really well before it dropped a seal but silly me still drove it and it caught fire due to a leaking fuel hose. I replaced what i seen was damaged it sat for about 9 months before the rebuild but ever since i have had it back it just hasnt been the same.

Dudemaaanownsanrx7

iTrader: (23)

i think the jap spec cars dont have a precat, but they still have a main cat. thats why you have an air pump. if you had no cat you would have no need for an air pump. take the exhaust apart right after the downpipe. take a pic of what you see and post it here. If the cat is clogged you will probably be able to tell all by yourself. Its pretty obvious.

VivaLaMikey

thanks for clearing that up i will do that as soon as i get time.

i just put a second hand replacement tps on and tuned it before i got most of the specs within range apart from the WOT range is only about 0.03v out at the most will this cause any issues, it seemed to have fixed all my backfires, bucking and restored a small amount of my lost power.

i also checked my MAP sensor with a multimeter turns out its pretty screwed it came out at 5.3v as opposed to the specified 1.3-1.6 and with blocked map vacuum hose it was only 0.07v as to 2.38-2.78v

so its running a little better will try to check my cat and get that new sensor and will let you know how it goes.

any other ideas your able to come up with while im at it would be great saves me pulling it apart 3-4 times lol

will also try to get that pic of the cat up and a video or sound recording of the air pump.

Dudemaaanownsanrx7

iTrader: (23)

Lol thats your problem then if your map sensor readings are that far off the car will run like ****. I wouldn't even bother with the cat until you change the map sensor out. That will most likely fix your problems

rx-7na

iTrader: (3)

You might want to check all your electrical connections too. Also check the solenoids and vacuum lines. Check that your plugs going into the ECU are plugged in the right slots. If I can remember right, when I did my rebuild I plugged in the wire harness going into the main ECU wrong. There were two plug-ins with the same plug ends and I had them in the wrong positions. Car started up and idled fine but when I went to go on the gas, the car would bog and not build any boost.

dgeesaman

iTrader: (7)

Did you replace ALL wiring and sensors in the vicinity of the fire?

You need to troubleshoot the MAP or TPS issues before worrying about boost.

Dave

TRWeiss1

iTrader: (20)

I'm having a similar issue with mine that just started...If I get on the gas 1/2-3/4 throttle in any gear, then shift as soon as the second turbo begins to spool, and hammer it in the next gear, boost builds very slowly (as if the wastegate to the first turbo is stuck open at lower rpms, diverting all exhaust gases to the second turbo). Eventually, once higher rpms are reached the boost builds all the way, and when you shift the next gear everything is fine.

I noticed that when I went half throttle in first today, shifted at 4500, then was just on the throttle lightly in second...the exhaust note sounded exactly like it does when the second turbo is spooling, and boost was building VERY slowly at lower rpms...I'm on stock twins, sequential....sounds like I'm having a problem similar to yours.

I'm guessing it's the solenoid that actuates the wastegate on the first turbo, causing it to stick open and only spool the larger turbo at lower rpms....Valid theory?

Mahjik

iTrader: (1)

Check this thread:

https://www.rx7club.com/3rd-gen-archives-73/weird-boost-issue-685269/

Your issue sounds very similar.

TRWeiss1

iTrader: (20)

Thanks Mahjik, very helpful as always!

After reading through that whole thread, it looks like it can be traced back to ONE faulty solenoid!

dgeesaman

iTrader: (7)

If you think you have the TC solenoid problem, I would replace both TC solenoids.

Dave

VivaLaMikey

Thanks for all your help guy's im currently waiting on a MAP sensor to arrive so will update the post once it gets here.
With the fire i did not replace everything immediately, as im not sure what was effected by the fire im just replacing parts and ruling out problems as i go along so far its been getting better but didnt want to waste so much money immediately replacing everything if you get my drift.

VivaLaMikey

just put the second hand map sensor on today and did a volt test i got the same sort of readings way off the specified ones but that seems weird as it came off a running car according to the guy i got it off so i think i'll try another one off another running car and see what i get out of 3. and im guessing a TC solenoid is the throttle control solenoid? i had a quick browse through the fsm and cant seem to find where its located any help so i can test that? also are there any specific readings i'll need to test the TC solenoid, Thanks in advance

VivaLaMikey

I have tried nearly all the suggestions i have got and so far nothing the TPS i replaced seemed to fix my idle problems but still have the boost issues and spitting and bogging out, i tried the MAP sensor couple of weeks ago and nothing then i swapped my ECU with a mates yesterday seeing as i couldnt shordted it when i had the fire but that didnt change anything, although he said his one was doing the same thing before he dropped his seals. Any other suggestions as ive come to the end of the road and dont want to think my engine has gone just 9,000km after a rebuild