Bigretardhead

well, like I said above, my 87 TII is running like crap.
there are a few things wrond, so I'll just list them, and you guys can tell me what you think.

1: if its idleing, or below 3000rpm and I mash on the gas pedal, it stutters, and sometimes almost dies, and then it revs up. this is sitting in neutral. its kind of hard to explain. its like, you mash on the gas pedal and it goes "ba-ba-ba-ba-ba-ba-vroooooooom"

2: Its only boosting 4psi ? WTF? how does that work?
I got up to 5 psi at 80 mph. but still, shouldn't it be AT LEAST 7 psi ? also, it doesn't build any boost till about 5000 rpm in 1st, and then it only gets like 1-2 psi. by 6500 in 2nd it barely makes it to 3psi. also, I checked the turbo 3 days ago when I was putting the stock TID back on, and there is VERY little shaft play, and it seemed to rotate smoothly.


3: it only pulls 12-15 In hg at idle at a VERY solid 650 rpm. I really don't think there's a vacuum leak because the idle is so solid, but there could be a small one. also, I checked the compression like 2 months ago and it was about 105 all around (and this is at almost 6000 feet).
I should probably check it again, but I doubt its bad.

4: I thought there was something else, but I can't remember right now.

I just changed my plug wires(was running baf before changing them also), and the timing is right on. the spark plugs are at about 3000 miles old, I'll let you guys see if they look okay or not. my fuel filter is old, but a new one is supposed to arrive tomorrow.
is there anything else I should check? what part could go bad to cause this?

also, my mods are(that affect the engine):

2.5inch downpipe. no cat.
HKS 60mm dual cat-back
k&n cone filter.
walbro fuel pump
CP racing FCD.
also, I don't think the stock boost sensor is working.

any help would be appreciated.

oh. and here are the pics of the spark plugs:
left is leading plug, right is trailing plug. this is from the rear rotor. the front plugs look almost exactly the same.

Fingers

You got all the symptoms better get the compression tester out. Also check for vacuum leaks. Specifically intercooler piping and TID. It must be a BIGGGGGGGGG *** leak, or your compression is fucked.

Bigretardhead

yeah. **** ***

well, its better to get it now then after a seal blows.

and at least I've got $2000 in the bank.

rx7raca

you wouldnt believe it but tonight the same bullshit happened to me, i found the nipple that a vaccum line popped off of, but my engine wouldnt go unless i gave it about 10% thottle, it would jus bog out an buck like a bitch, at first i thought i broke an apex seal, i was racing an it just started bucking as soon as i let off the gas, the engine has about 1200-1300 miles on it so i thought it was gone, but i didnt even bring it past redline so i wasnt sure why that would happen.
but my friend found the nipple an told me the engine was fine...so tomorrow im ripping out every vaccum line that isnt needed, ie. emissions crap.

on t2s vaccum leaks can happen very easily, so get yourself a can of carb cleaner an start spraying...me im not gonna even deal with it, just rip everything out, im tired of it!

Terrh

iTrader: (7)

you're CERTAIN that that's all that it's boosting? measured with an aftermarket NON-STOCK gauge?

it idles fine, starts easily, etc? your compression should be okay .... check it if you want, but it's probably just fine.
maybe your wastegate is siezed open? vacuum leak?

your car isn't going to pull as much vacuum at 6500 feet as it would at sea level... or would it? hmm, I'm not sure on this one..

rotary>piston

well I live 2-3 miles away from him, and my MR2 pulls 18-20 In Hg vacuum. Yeah, it's a piston, but it should be similar.

Fingers

You're right. Maybe you can try putting your timing belt on his and see if that helps?

Rotary is not at all like piston, the vacuum measurements are different, the compression measurements are different, exhaust pulses, fires three times per revolution, whereas piston fires once every four strokes, etc etc etc etc...


ANNNYYYWWAAAYYYSSS.... 15+ in hg is good. Anything below that is either a street/bridgeported motor, or a motor on it's last leg.

DAN CARWIN

why are ROTARY engines such pieces of ****? especialy T2 I live in Aurora Co and my **** acts up all the time to?

rotary>piston

they aren't, you just ended up with a problem car I guess.

I know all about rotaries, I have what, 800 posts? I owned a GTUs for a year, believe me, I know the in's and out's of rotaries.
I thought rotaries had a similar vacuum though? I always remembered hearing 17-20 as good numbers for a seven.
Well, whatever. We tested the compression tonight, it's about 100 on all sides on the front rotor, and 75-75-80 on the rear. 75 is low, yes, but at this altitude it isn't terrible. I think my FSM said about 65-70 psi was minimum at this altitude.
Even if it is too low, should it really make the car run the way it does? I mean come on, 4 psi? With his exhaust, intake, and other mods it should be creeping to at least 8 or so.

Travis, I really think you should just talk to rotaryspecialists and have them check it out. A new engine is pretty expensive no matter which route you take.

BlackR1

Check the small things first-- AFM connection and hose, the dozen or so vacuum lines, spark plugs and coil packs...afterwards, get a compression check. Shouldnt take all too long.

It really sounds like AFM issues, unlikely the TPS but check anyhow, and has a lot of blown engine symptoms

BlackR1

.

DAN CARWIN

Thats funny you would trust Terry at Rotary specialist, Just to let you know between my freind and I we have owned well over 30 rx7s half first gens and half second gens. the point I'm trying to make is that you will never have a perfectly running T2 or any 7 for that matter. their is always something wrong with them. I have 9k under the hood of mine alone.

Bigretardhead

no, you got that wrong. to start, front was about 80-80-80, rear was about 75-75-80. then we ATF'd it and did some water injection/steam cleaning stuff, and front was about 85-85-85, and rear was the same.

I just started the engine up, and after running about 5 minutes(its at 140 degrees), and still idleing at 1400. you can mash on the gas pedal, and it has NO hesitation whatsoever. hopefully that will continue once its warm. oh, and it was pulling about 15 in Hg. I'm going to go drive it and see what happens.

Bigretardhead

why is that? is there something wrong with him/the shop?

Bigretardhead

well, I just finished driving it, and its not any better. well, I didn't really get a chance to drive it hard, and see if it still boosts bad because its blowing out tons of oil smoke. at first I thought it was just from the ATF we put in last night, but we ran it for at least 30 minutes last night after that(along with some water injection), and it ran for at least an hour today, and it hasn't gotten ANY better. I drove a few blocks, in the direction to go somewhere to test, and in my rear view mirror I saw a bunch of blueish smoke pouring out so I turned around. I would have DEFINETLY gotten pulled over.

so now I'm thinking an oil seal? or in the turbo? would just bad compression cause oil smoke to come out? would bad oil seals cause the compression to lower? I'll pull off the turbo first and check that.

oh, and its back to pulling 12-13 in Hg.

and there are no vacuum leaks(I tested again).

yes

I checked the AFM connection, checked for vac leaks, checked spark plugs (picture above), haven't checked coil packs, checked compression. all turned out okay except the compression which I guess wasn't EXTREMELY terrible, but certainley not good.

is there anything that could cause the compression to go down besides the apex/side seals ?

rotary>piston

oh, well I was just going by what i thought you said on those comp numbers. I never actually watched the guage remember?

And Travis: does the oil smoke increase when under boost? Or did you even get a chance to test that? If it does it a lot more under boost then it's probably the turbo. If it's more RPM dependent then it's probably the oil control rings.

I've had enough crappy turbo cars try to challenge me to know what a blown turbo does to the exhaust. They always try to get me to go, I don't, and they go flying away trying to look cool with a cloud of smoke following them .

Bigretardhead

bump.

I don't know if it increases under boost. I don't think so. its really just gets worse when I revv it. it doesn't matter if I'm boosting or not(I think).

whatever. I think I'm just going to try and rebuild it myself. and maybe take it to some shop to have them do the porting . maybe I'll save enough money like that that I'll be able to upgrade the turbo also. it'd be a nice compliment with my waiting to be installed FMIC.

Bigretardhead

bump.

should I assume my engine is dead? or keep looking for other problems?

rotary>piston

I really think you should get it checked out by a real rotary expert before you make any decisions. This is a major thing and a lot of money, so you should be absolutely sure before you do anything.