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Questions on FC Problems

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Old Apr 25, 2004 | 01:25 AM
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Questions on FC Problems

I went to try to buy an 88 today, and had some trouble. The guy said hed been driving it, but got another car. So I cranked it up, it idled a little rough, but didnt stall. I took it from one end of the parking lot to the other, and as i was turning (slowing down to where rpms dropped below 1.5k), the car cut off, and would not crank back up.

After that it would turn over and not crank. I went and bought new plugs(autolite, the right ones i hope!, top and bottom are not different are they?), and it cranked, but ran rough. The old plugs smelled like fuel. Well, we took it for a spin again and it did the same thing. After that we let it sit after being cranked and it wouldnt idle anymore without being given gas, and wouldnt hold a steady rpm. Would surge, like for example if you held it at 3500 would surge from 3000 to 4000 or so.

We decided to take it on a final run, and it cut out again. This time it wouldnt crank back up.

So finally, i decided to leave. Its kinda a piece, but I really want it. He only wants $1200 for it, and i talked him down to $900. It has 170k but supposedly 15k on a rebuild.

I dont know much about rotaries, as I am a domestic V8 guy, so maybe yall can help. My best guess is either an internal compression problem (blown apex seal?) or either an ignition problem.

Let me know what yall think, as I really want to get into the FCs.

PS - I am going to look at a starion tomorrow. Keep me away from the dirty DSMs, and tell me how to get this rotary to run!

-Marc
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Old Apr 25, 2004 | 02:02 AM
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Here is something to try... Those idle issues are controlled by a TPS (Throttle Position Sensor) ... If you have a volt meter around you will need it... Its pretty easy, I didn't see you mention turbo, but these directions will have both for you...

Originally posted by Aaron Cake
If you need 4 turns of the TPS screw to adjust things "properly", then there's something else seriously wrong. The proper procedure is below:

Adjusting the TPS is a simple maintenance item that should be preformed at any oil change. The benefits include better gas mileage, better performance and a smoother idle. Adjustment only takes a few minutes if you follow the directions below.

What You Need
· Ohmmeter
· Flathead Screwdriver
· Half an hour

How To Adjust
· Warm the car completely by driving for 20 minutes
· If your car is a turbo, remove the intercooler. Loosen the hose clamps on the inlet and outlet, remove the vacuum line, and then remove the four bolts (I believe 11 or 12MM). Lift off the cooler. Do this quickly so the car does not cool.
· Unplug the TPS. On 89+ cars, you want to unplug the connector leading from the lower TPS.
· Hold the TPS connector so the hump points up. Connect your meter between top connection and rightmost connection.
· Adjust the stop screw until the meter reads 1K (1000 Ohms)
· Plug the TPS back in
· If necessary, reinstall the intercooler. Don’t overtighten the hose clamps
· Drive the car for a few minutes, then repeat the procedure
Found at: https://www.rx7club.com/showthread.php?s=&threadid=235007&highlight=settin g+tps

However I also have a Starion along with my Turbo II. 2.6L of Boosting fun... Starions with 87-89 were the better half for power. Their injectors were able to handle a bit more abuse, same with the rear end. Watch out as Starion heads warp/crack VERY easily. Myself I have an 83 Starion. Good fun. But my friend let me drive his 87 FC and I had to have one... So here I am.

Now for some other reasons for your problems:
Usually people set the idle high to hide other problems, vacuum leaks, and what not you might bring some carb cleaner with you and spray around for some vac leaks.... carefully... Around the turbo if you have one is a pretty easy spot to crack... Theres also a chance that they may have not replaced the Plennum gasket that goes between the Upper Intake manafold and the rest of the motor or something of that sort giving you some crappy vacuum leaks. (Thats what many others have had, from what ive read.)

At the top of this forum theres a FAQ which has links to very good information, FREE factory service manual downloads. So you can either just print out a Vacuum diagram you can look for mixed up lines etc. You could have low compression... but you didn't mention if you had any large amounts of smoke when you started up? White, blue? Black???
White is usually coolant.
Blue is usually oil/turbo seals.
Black is usually running too rich.

Theres some things to look at, hopefully its something easy like a vac line or two mixed up. Good luck!
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Old Apr 25, 2004 | 03:13 AM
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Autolite plugs? wrong ones!!

NGK plugs BUR7EQ for Leading plugs (bottom)
NGK plugs BUR9EQ for trailing plugs (top)
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Old Apr 25, 2004 | 09:47 AM
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Originally posted by WolfsRx7
Autolite plugs? wrong ones!!

NGK plugs BUR7EQ for Leading plugs (bottom)
NGK plugs BUR9EQ for trailing plugs (top)
So the top plugs have to be different than the bottom plugs? I bought the cheapest thing advance had, just to try to get it running. They said it wouldnt matter, that top and bottom should be the same.

Anyone else think it could be flooded too? And the TPS thing? I might go try to take another look at it today. Any ideas will be helpful!

-Marc
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Old Apr 25, 2004 | 09:59 AM
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uh....take it from me:

stay away from Starions......I had one, and they are nothing but trouble. Are you looking at wide body or the slim version? the biggest problems you will run into with the starion are electrical issues - ECU, vac advance, etc etc...and it's a truck engine with a bolted on turbo, so yes, lots of torque, but can't rev past 5K without huffing and puffing...

I enjoy my T2 much more than my starion, no comparison!

if you are going to do DSMs, get an Eclipse...my girl friend had one and it was not too bad. Unlike the starion, at least you can get replacement and aftermarket parts!

When buying a car, you can't just look at the initial purchase price alone..you need to consider long term costs and benefits.

About the Rx7...no one in this forum can definitively tell you what's wrong without actually spending time testing/evaluating the problem. If you have to do anything, then run a compression check (search!). If the compression is good, and the transmision shifts good, then you have a shot at getting a decent car.

Just from your description you may be looking at leaky injectors that dump to much fuel/cause hot start problem.

My 2 cents. Best of luck.

dewey
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Old Apr 25, 2004 | 10:01 AM
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never listen to anyone at a parts store when dealing with a rotary engine, most people dont even know what it is let alone how it works.
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Old Apr 25, 2004 | 10:02 AM
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It's probably your plugs.They aren't fiiring correctly which leads to flooding.Also check the timing.You'll have to get the idle as close to 750 rpm's as possible to do it correctly.Use a car powered timing light and hook the inductor to the #1 leading coil wire.Then line up the first mark on the pulley to the pointer by turning the crank angle sensor(looks simaler to a distributor) left or right.
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Old Apr 25, 2004 | 10:03 AM
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Okay, how can I do a compression check? I would love to go buy this car today!

Help me out!

If that is the case it will be narrowed down to ECU, Fuel, or spark problem...
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Old Apr 25, 2004 | 10:24 AM
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Assume it is the timing, how do you adjust it on that car?
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Old Apr 25, 2004 | 04:46 PM
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TTT?
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Old Apr 25, 2004 | 06:37 PM
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You need to get that idle down to at least 800rpm or maybe 850 at the most before you can go setting the timing... Otherwise the points will be bouncing all over the place and you'll never be able to set it...

Definately take others advice. Don't take word from the guy in the autoparts store. There are definately two types of plugs, the car wont like you if you use the same plugs all around..

I'll try and find a better post about setting timing, until then here's my crappy description....

Once you get the idle down.. its much like a regualr car... execpt there are 2 marks not one... Since we have two coils, Leading and Trailing... The way it works is if all is well you can set Leading and then Trialing will follow and sit where its supposed to be.. (at least thats the way I understand it.) If they don't follow meaning you set Leading and Trialing falls into place.. but instead trailing is all over the place, something else is going on.

Theres a Crank Angle sensor, much like a distributer, you loosen a bolt and it will pivot left and right. If you use a timing light which runs off the power of the car, NOT a battery powered timing light, then hook the signal wire to Leading 1, (indicated with L1) if you look down behind the clutch fan (meaning closest to the engine) like most cars there will be a spot where the timing marks are, its a little nub sticking out... im not entirely sure the best way to describe it.... and you will have a Yellow and a Red timing mark... I think on L1 the mark should be lined up with Yellow, and then move the singal wire to T1, and take a look at that same mark. If you have the yellow one in place then the red one should just follow it no problem and be dead on the mark.
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Old Apr 25, 2004 | 06:57 PM
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Originally posted by duehuynh
uh....take it from me:

stay away from Starions......I had one, and they are nothing but trouble. Are you looking at wide body or the slim version? the biggest problems you will run into with the starion are electrical issues - ECU, vac advance, etc etc...and it's a truck engine with a bolted on turbo, so yes, lots of torque, but can't rev past 5K without huffing and puffing...
Not to start an agrument, but same can be said about any car with any high age/miles put on it. It always depends on how much maintance was put in by the previous owner. So you could have had bad problems simply becuase of a crappy previous owner. Much like my RX-7 was abused for 100k and runs a hell of alot worse then my Starion with 165k. Both origional motors and all. You can't really compare a piston car revs to a rotary anyways. These cars (rx7's) rev like no other... maybe a bike... but eh.

But yes, aftermarket parts are a bitch to find for a starion, most don't even exist.. Same with bolt patterns for rims, you don't have many choices. Same thing goes though you can change out the hubs to something more common if you were inclined to do so. With any old car, there will be maintance, wiring needing repairing, bad vac lines, vac advance... its all part of that 16 years and climbing thing.

With either car you will need to be learning the tricks they both have....Don't let the rotary scare you. It was alot easier for me to pick up then say playing with all the valves, timing chains/guides fun ive had on other cars.

But both of what we said are all personal experiences and opinions anyways. Good luck.
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Old Apr 25, 2004 | 07:51 PM
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for starions.. go here http://www.starconquer.com/

for rx7's, you're on the right forum
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Old Apr 26, 2004 | 01:34 AM
  #14  
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Originally posted by BC-X
for starions.. go here http://www.starconquer.com/

for rx7's, you're on the right forum
or for the tech forums like you have here.. the Starion ones are:

http://www.starquestclub.com/
and
http://starquest.i-x.net/

Those are the two main ones I keep tabs on. Incase your interested in browsing their forums as well.

Otherwise report back once youve fixed your spark plug problems... and well my guess is the idle ones will be history too.. or at least less of a problem.
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Old Apr 26, 2004 | 01:58 AM
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Lightbulb What abpout this

All these suggestions could be right... But did anyone think to check the AFM as well.... Just a thought
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Old Apr 26, 2004 | 05:36 AM
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AFM? I also talked to some guy today who works on RX7s alot, who said there is something right around where the throttle cable attaches, some sort of sensor (couldnt understand him and if he meant TPS) and he said he was like 90% sure that it was bad.

P.S. - Did a search and still dont know how to do a compression check. if you will tell me how, i will do it!
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