SonicRaT

iTrader: (6)

I need some help with my Turbo2, it starts up fine, but won't idle where it should, it just bounces up and down up and down (I've checked the TPS a million damn times) and it's not the cause, I can get it to idle just fine at 1.5K without bouncing, but if I drive it around, 5 minutes into the drive it'll just start hesitating/bogging at ~3-4K anywhere in there, then if I come to a stop and try to rev it up while I'm stopped, it won't rev anywhere past 3K or 4K, I shut the car off and let it sit for a few minutes, start it up and I can drive for another 5 minutes and it does it all over again, the temp gauge is staying dead smack at 1/2, no emissions, no thermowax, no AWS. Only engine code I have at the moment is my pressure sensor (doesn't hold vacuum ) Any suggestions/idea's to look at?

BoostedRotors

Unhook the TPS and drive it for 10 mins or so...see what happens.

SonicRaT

iTrader: (6)

Did the same thing, no difference at all, still drove just fine for 5 minutes, and then it just bogs and won't rev anymore, it'll rev REAAALLY slowly, but nowhere over 5K once it does that. Could it be something strange with my secondaries not firing once the car warms up? I'm running out of idea's quick, and nothing seems to make it any better.

BoostedRotors

Wow, thats crazy. Have you checked all your injector wires and what not? though i dont know how that would be heat related...odd.

BoostedRotors

perhaps the injectors get stuck open once the car is warm and cause it to run extremely rich? can you smell gas? Again, im just tossing stuff out here,

SonicRaT

iTrader: (6)

Nah, it's running extremely lean once this happens, it runs rich for the first 5 minutes (runs good actually) then it just leans waaay out and kicks and bucks and throws a fit, then it won't rev at all.

The Ace

I was about to post a reply with "suspect huge vacuum leak", and then I saw your last update SonicRat....

....now it sounds like a huge vacuum leak more than before Air is getting in without being metered....the fact that this happens after the engine bay warms up means that this is a crack/hole that widens with heat.

I'd start looking real hard at EVERY plastic/rubber/silicone hose and connector in the engine bay with a stethoscope....

EDIT: I know you'll probably say that you have looked, but so had I, and although I didnt have much of a problem (like you), I did notice a slight problem with idle after car warmed up. It finaly turned out to be a relatively big crack in the TID, which opened up with heat, and which I couldnt find with CC....

SonicRaT

iTrader: (6)

been there, done that, replaced them all There isn't one old hose on the damn car, there isn't one thing I haven't checked yet

The Ace

Problem in fuel line/with fuel pump/with fuel injectors ??

Have you measured the voltage on the pump ? Dont know/remember if you have rewired yours, but can you hear vacuum being released when you open the gas tank with very little fuel left in ? Maybe fuel system is not able to hold vacuum, and you lose fuel pressure ?

Dont think the injectors are faulty, but because you lean out, it could be that you are not getting enough fuel....maybe you should just replace the two filters, and drop some cleaner in there....

SonicRaT

iTrader: (6)

Hmmm, tank pressure, never thought of that... I have about 1/4 tank of gas at the moment.... but you know I do have my old gas tank line from the charcoal canister venting to open air, which could be a pressure issue... And no I haven't rewired the fuel pump, good idea. I'm pretty sure it's not the injectors, I mean the damn thing will run fine or the first 5 minutes and then it starts happening, during those first minutes it runs fine (except for the damn idle) I'll check out my fuel pump voltage for sure, and I'll also plug that damn charcoal canister line. Thanks for the tip

SonicRaT

iTrader: (6)

Does that sound like a possible cause? Maybe a clogged filter/not enough pressure in the fuel system due to the open vent?

The Ace

The thing is, if it was due to something that was always in effecte (like this vented line), then this should have been happening from the very first moment. Dont know what exactly is supposed to happen in the Rex's engine after 5 minutes of running, but the first thing that comes to mind is that the heat produced up to that point effects *something* (which could/should be a plastic or rubber hose).....

Anyway, filters are easy/cheap to replace, so start with those. Get a DMM and check voltage at fuel pump (again, very easy), check for vacuum before putting in some gas, and then go from there....

HuggyBear

well im no rotary genius but ill offer my suggestion.

i assume uv searched for a vaccum leak thoroughly(spray bottle, stethascope...ect..)

checking the fuel delivery system. if there some sort of wiring/fuse that could be shorting after to car heats up?

also have you checked the ignition system? maybe theres something shorting out and not firing after warmup.

those are my newb suggestions

deadRX7Conv

Test the AFM, O2 sensor, & water temp sensor(unplug). Swap the fuelpump and filter.
And since you have a pressure sensor code, replace it.
What do you mean by "doesn't hold vacuum"?

SonicRaT

iTrader: (6)

The pressure sensor should hold vacuum and have a certain reading with vacuum, but it doesn't hold vacuum and the reading is always wrong I've tested the AFM, it was within spec, checked the water temp sensor already, o2 sensor is brand new

HAILERS

Is that a turbo boost/pressure sensor or a n/a??? I just took my connector off my turboii and drove around the block. No hesitation with it off and over five grand while boosting. Did notice that the afr in the car does not show as rich a reading doing this vs when the connector is on the boost/pressure sensor. So I'd say, beware boosting the engine while the boost/pressure sensor is disfunctional. Might cause a problem.

The up and down idle thing I've experienced only one time on the turbo. It was a part of the black cam that the secondary throttles ride on, on a unfiddled with turbo. The black plastic shattered and pieces were keeping the secondaries open a touch. I think the car got confused, because the tps was seeing a closed throttle, but the secondaries were letting in air when they shouldn't have. Anyway after clearing out the shattered plastic, the car ran as it should. That my story and I'm sticking with it. I guess what I'm saying, is take a look and see if the secondaries are closing fully with the primary.

SonicRaT

iTrader: (6)

Thanks for the advice hailers, but I checked that already, I had thought my plates were hanging open, but they aren't, I checked and they are closing fully, and I removed the high idle cam/etc so that's not the issue.

HAILERS

Don't know about 90's. But on the back of the throttle body on a 87 there are four *vacuum* nipples. Only one is truly a vacuum. I was wondering IF it was possible that on your car, that you might have put a hose that does not require a vacuum, on a nipple that is suckinga vacuum.

One a 87 two of those hose go to the oil injector spider and the other to the fuel injector *air bleeds*.

So if they were put on wrong, it can cause a rotten idle. Its just a thought.

In the earlier post, I was talking about a damper at the FRONT of the throttle body that rides on a black cam outfit that slows down the opening and closing of the front set of secondary throttle plates. Thats just a clarification of what I was talking about. If thats what you meant you removed, then just forget this paragraph.

The above is just directed at the idle problem, nothing else.

SonicRaT

iTrader: (6)

Oh, I see what you mean, and yeah, it was getting stuck but I fixed that issue, I thought you meant the other side On 89+'s there are 3 nipples, 1 is for the vacuum spider, the other two I have plugged

HAILERS

That one vac hose. What is it going to??? And is this a recent problem that just cropped up or a ongoing thing?

The runs good for five and then not run good, kinda sounds like its just starving for SOME reason, or the blowoff valve is opening???when it shouldn't? Starvation is what I hear when you say you come to a stop and can't rev it over three grand.

SonicRaT

iTrader: (6)

yeah, it drives fine for about 3 minutes, then it just runs for plain **** (it'll start bucking and kicking me all around while I'm accelerating) Blow-off valve shouldn't be opening, seeing as I'm not even over 5psi when this happens. That vac hose runs to the oil injectors (the only one on the back that isn't plugged) All the rest are plugged up, going to check again for more vacuum leaks and then swap fuel filters, check the pump for voltage/etc.

SonicRaT

iTrader: (6)

ugh, only 8volts at the fuel pump, and none are 13

vosko

iTrader: (4)

i had a similar problem it was just a vacuum leak. i'd check your AFM

HAILERS

The fuel pump does not switch to `12 plus volts unless you are under boost. Something you have not been doing as of late.

If the only hose at the back is the one to the spider, there is no way you could have connected it up wrong since its a larger hose than the rest. So that idea is OUT.

HAILERS

Did you try the afm off your other car????