Rotory

iTrader: (1)

The good:

Well finally I have gotten a new 1987 Turbo II. It's been nearly 4 years. After many of the "The RX7-CLUB misses you!" emails I couldn't take it anymore so I bought another. 100k miles on the chassis. It has a rebuild in it, supposedly 30k miles on the engine. No paperwork on the rebuild but it sure feels like it has been rebuilt. Never has trouble starting while hot/flooding. Coolant stays full. So far soo good. Better than both previous TII's that I owned. It has an aftermarket intake and a 3 inch straight-through exhaust. I know that is a dangerous setup due to fuel cut, but i havent even gotten past the main problem which is much lower in the RPM range(no where near fuel cut).

The bad:

When I got it the idle would bounce from 1200-1800. I now have the idle down to around 900-1000, by finding a few vac leaks and adjusting a few screws on the TB while it was running with that piece of PVC test pipe in place. I still think the guy I bought it from doesn't have the vac routing right and I have a few pics for u guys to look at, and tell me if I should change anything. I can explain any routing that is on the car to you if needed. The car bucks like crazy when I'm just trying to barely keep my foot on the gas. Like when I'm trying to do the speed limit or pulling into a driveway. It runs great when I'm actually accelerating, pulls so hard and smooth. On decleration it runs fine, a little backfiring(that I like), but nice and smooth. It's just at like 2 % throttle. The previous owner removed alot of stuff, P/S, A/C, stock fan(replaced with electric), alot of the various valves that helps idle while under load. The bucking is WAAAY worse in 1st, 2nd, and 3rd gears. I've read alot and I know it sounds like TPS. I have a new one I just tested and will be putting it on the car tomorrow and setting it(weather permitting). I'm hoping this fixes it. But please I know u smart guys will have some questions about the routing of my vacs cause I'm totally not sure it's right, it is SOOO rigged. Anyways I'm gonna attach some pics. Any help will be greatly appreciated.

<a href="http://s564.photobucket.com/albums/ss90/rotory7/?action=view&current=IMG_0313.jpg" target="_blank"><img src="http://i564.photobucket.com/albums/ss90/rotory7/IMG_0313.jpg" border="0" alt="Photobucket"></a>


<a href="http://s564.photobucket.com/albums/ss90/rotory7/?action=view&current=IMG_0315-1.jpg" target="_blank"><img src="http://i564.photobucket.com/albums/ss90/rotory7/IMG_0315-1.jpg" border="0" alt="Tail"></a>


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Like I said I'm not sure all the vacuum is running right so I will answer any questions or take any pics u guys want to help me out. I'll get back to you tomorrow about if the TPS made any improvements.

Raziel

iTrader: (1)

Could be a grounding issue. Check all the grounds. Yeah and you already know about the TPS hehe.

Rotory

iTrader: (1)

I will unbolt the grounds and clean them, but the previous owner knew of this also, so there are multiple new grounds on the car.There are three vac nipples on the front side of the UIM, the top one is capped,the bottom 2 are running to some kind of check valve and then into the vac line coming out of the the block where the oil filler neck mounts(last pic). Is this right?

Rotory

iTrader: (1)

Also i found that the screw near the boost sensor was turned all the way clockwise so i backed it off a good bit and that helped alot. i noticed something else on my way to work. It seems like as long as im under boost the car runs fine. it will be bucking, so i give it gas and spool up the turbo and its fine. Any ideas? i will still be putting on the new TPS and setting it when i get off work. sorry for my grammar im at work on a laptop and in a rush.

87 t-66

iTrader: (133)

i would also go towards the tps...i had the same problem on one of my cars and that turned out to be the culprit.

fix the front wiper haha

lastphaseofthis

iTrader: (8)

You my friend have a series 5(89-91) motor in your series 4(86[87 for turbo]-88). Curous is What ECU you are running, i see the N350 boost sensor, but no doubt, your motor has S5 Rotor housings, to say the least.

Rotory

iTrader: (1)

OMG dude are u sure?? Need more pics to be ceartin? The guy said it had an S5 turbo. I know it has an S4 throttlebody, well atleast it only has the one TPS. Which i replaced and set to 1vdc at idle just an hour ago as per what HAILERS said. SO with new TPS(set) and that screw by the boost sensor turned down a little the car does run WAY better. But still bucks/hesitates. It even does it in neutral really, when u are in neutral and hit the gas it hesitates before it revves up. The ECU is a 332. i have a spare 318 boost sensor off my parts car(87 TII) would that make a difference.

Rotory

iTrader: (1)

Oh and by the way when i pull up to a stop sign the rpms drop really low then come right back to 900-1000.

texFCturboII

iTrader: (17)

the guy could have just used s5 housings in the rebuild....

Rotory

iTrader: (1)

And that really wouldnt make any problem like mine?S4 TB and eveything hook up the same?

Rotory

iTrader: (1)

<embed width="448" height="361" type="application/x-shockwave-flash" wmode="transparent" src="http://i564.photobucket.com/player.swf?file=http://vid564.photobucket.com/albums/ss90/rotory7/SDV_0013.flv">


you can even see the hesitation in neutral i only hit the gas twice, then it drops low and stablizes

lastphaseofthis

iTrader: (8)

post pics of the turbo, mainly the hotside near the wastegate. and maybe a shot at the secondary Fuel rail.

I spy:
s4 oil return from turbo to S4 front cover.
S5 rotor housings/s5 water pump

S4 turbo ECU and boost sensor, the 318 is an NA and doesnt work with turbo ECU/motor.

i know the S5 rotor housings have diffrent leading spark plug hole timing, but only by maybe 5 degrees? i measured them on a pair once, it was dropped half and inch...
i am not sure what kinda of performance effect using S4 spark timing, on S5 housings has, but i know that i've been told to avoid doing that b/c of tuning issues.

the motor seems to run relativly well although, does it hold idle, or do you have to keep it idling?

i was suggest a reground, plenty of writeups around here. reground usually clears up hesitations, I.E the 3800 rpm hesi.

Boosted11

iTrader: (11)

Did you get the ecu ground? That ground is often not done due to the location. Aaroncake has a writeup on grounds and it shows you where it's. Does involve taking off the upper intake manifold.

Rotory

iTrader: (1)

I probably dont have the ecu ground but there are like 3 other non-stock grounds that i can see on the car. And just to clear things up its not the 3800rpm hesitation. It only does it when im trying to hold at like 2% throttle, what rpm its at really doesnt matter. I'll go take some more pics and get them posted. I wont really have the time to take the UIM off until sunday due to work. Any help on where my vac stuff should be run or a link to a thread that explains it well. it idles just fine around 900-1000. but as u can see in the video it stumbles as soon as i hit the gas and then its drops to like 300rpms before it will stabilize back at the 900. Ill go take some more pics and maybe a better video. I'm gonna rent a compression tester from advanced auto sunday and due a compression check. although im highly doubtful that it is blown, if it is blown and pulls as hard as it does I would hate to see how fast it is once I get it rebuilt. still leaning towards vac leak

lastphaseofthis

iTrader: (8)

What i was getting at is... it seems you have a Series 5 block with s4 wiring/ecu. the engine isnt getting enough fuel. as it's only being supplied with enough fuel for 180hp, you really need an s5 wiring hardness/ECU/sensors. not really all the expensive.

Rotory

iTrader: (1)

turbo hotside as requested

<a href="http://s564.photobucket.com/albums/ss90/rotory7/?action=view&current=IMG_0321.jpg" target="_blank"><img src="http://i564.photobucket.com/albums/ss90/rotory7/IMG_0321.jpg" border="0" alt="Turbo Hotside"></a>

unknown vac line near master cylinder, that isnt connected to anything

<a href="http://s564.photobucket.com/albums/ss90/rotory7/?action=view&current=IMG_0323.jpg" target="_blank"><img src="http://i564.photobucket.com/albums/ss90/rotory7/IMG_0323.jpg" border="0" alt="Unknown Line"></a>

weather permitting i will be taking the UIM off sunday so i will have more pictures and a better idea of what is going on. any more ideas and could someone explain my vacuum routing question from my first post.

Rotory

iTrader: (1)

well i really dont think much fuel is needed in second gear trying to do 30mph with my foot barely on the gas. if it was higher in the rpm range under boost i would agree with u. but it actually only acts right when i get on the throttle, so surely its getting enough fuel.

lastphaseofthis

iTrader: (8)

its not just enough fuel, but the right amount, too little in one spot, too much in a nother, the spark timing is also diffrence, the S4 and S5 ECus are two diffrent Creatures.

Your turbo charger itself is indeed a S5, probably an S5 engine with s4 front cover then.

you may have other problems, but to get the most out of the car, power/effciency wise, you will need an after market ECU or, at least an S5 ecu, or maybe checkout pocketlogger.com for an Rtek7. 2.0