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Can't rev over 2k.

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Old 12-05-08, 11:32 PM
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Can't rev over 2k.

Fresh Kevin Landers rebuild. Engine turned over first try.

Car will not rev over 2k RPM's with any amount of throttle, even WOT.

Lots of smoke on startup.

No BAC, TPS completely out of whack, no o2 sensor connected.

My ideas are leaking injectors or the TPS is completely fuxored. (I ohm tested my TPS before, and it read around 2k with the plunger extended, and infinite when depressed)

I have a new/used tested TPS on the way, but in the meantime does anyone want to take a stab at this?
Old 12-06-08, 12:22 AM
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i would guess TPS aswell, just wait until your **** arrives and give it another try.
Old 12-06-08, 08:27 AM
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Well, if you think its the TPS.......why in the world don't you just disconnect it and see what happens?????

Maybe you have the Trail sparkplugso on wrong? Take a look even if you KNOW they're on right.

02 sensor is not a player in any way shape or form.

Smoke is hopefully, just the assy lube getting thrown in the exhaust and won't burn away till you have the engine running for some reasonable period of time. What? 30min to a hour?

Last edited by HAILERS; 12-06-08 at 08:30 AM.
Old 12-06-08, 02:57 PM
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Sounds EXACTLY like the symptoms my car had with a dead TPS, except it'd rev to about 3.5k.

no idea about the startup smoke; what color is it?
Old 12-06-08, 04:46 PM
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It's certainly not coolant, just exhaust smoke, or could be assembly lube maybe.

The engine has less than 10 minutes of run time. The smoke also comes out in a big cloud right at startup, dies down a lot right after.
Old 12-06-08, 04:54 PM
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maf??
Old 12-06-08, 05:50 PM
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The AFM resistances checked out good.
Old 12-06-08, 05:52 PM
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The smoke does it burn your eyes/smell potent of gas? It's probably tons of unburnt fuel...
Old 12-09-08, 09:56 PM
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So this is where i stand with this dreaded problem.

New TPS, resistance checked.
Timing set perfectly, plugs/wires on right.
Car turns on, so it gets fuel/air/spark.

Requires a LOT of throttle to stay running, (full emissions removal, BAC removal, TB mod).

The car does not stay running long enough to warm up.
No o2 sensor hooked up, AFM was resistance checked, but not sure if an AFM can have bad readings.

Injectors are in rough shape, could be leaking.

Fairly positive i have no vacuum leaks. I don't have many potential spots for leaks besides the intake manifolds. A lot of the un-necessary vacuum lines/spiders nest has been removed/blocked off.

If i think of anything else i will add it.
Old 12-09-08, 10:16 PM
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a manifold leak would give you a bad idle, but would not stop you from revving up. What are the plugs like? Is it making decent compression (since it was just rebuilt), and is it dead-set at 2k rpm cutout, or if you give it lighter throttle, can you get the revs up to 3500 rpm?
Old 12-09-08, 11:34 PM
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FULL throttle to keep the car alive. Hunts from 800-2000 RPM's. Plugs are brand new.
Old 12-10-08, 09:06 AM
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What happens if the TPS plug is DISCONNECTED?
Old 12-10-08, 10:56 PM
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Nothing noticeably different.
Old 12-10-08, 11:58 PM
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ok i am assuming that the pic of the turbo 2 is the car we are talking about so you say you removed the bac valve. I've heard alot that when you remove the bac valve it will give you a rough idle and when i did my emissions removal just for ***** and giggles i took off the bac valve and it ran like *** so i had to put it back on then it ran fine. now as far as the reving issue goes, when you are trying to keep ot running is it crackling and back firing. if so you might want to check your water thermo sensor its a cheap part and i had similar symptoms and that worked for me



P.S and by the way if its a fresh rebuild and only had 10minutes of run time don't be giving it full throttle to keep it running. you don't want to pop a fresh built motor that i'm sure you paid a pretty penny for.
Old 12-11-08, 12:03 AM
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its definatly DEFINATLY the tps sensor!
Old 12-11-08, 12:23 AM
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Originally Posted by SleepeR1st
Nothing noticeably different.

100% NOT the TPS then. A disconnected TPS CANNOT keep the engine from reving to 8000 rpm or any rpm inbetween zero and 8000rpm.

A faulty TPS CONNECTED up to the harness MIGHT cause a engine to not rev above a certain rpm because it MIGHT cause fuel cut.

NO TPS (as in the lack of one on the engine), will not result in that happening.

A disconnected water thermosensor on the back of the water pump housing will cause a difficult start if the weather is cool to cold. Once the engine warms up it won't effect anything because the ECU will default to 180*F temp i.e. normal operating temperature.

New engine MIGHT have the end piece on the apex seal still glue to the apex seal and that might result in low compression. MIght take a few minutes to seperate from the apex seal.

Bad gas might cause a problem since the engine has been sent out to be rebuilt. Depends on how long this down period was. I think it would take six months to turn to turpentine. Just a Guess and nothing more.

IF you jumper the yellow check connector with key On, and hear the fuel run thru the rails continuously, then it's not a clogged fuel filter imho.

The checks of the AFM in the manual are not that conclusive. Their more or less a continuity check imho that anything. They don't tell you if the vane in the afm is where it should be when running or if the carbon track is any good inside the afm. Unless there's evidence of Tampering of the AFM, then it's probably not the problem. Tampering would be the back plastic cover having evidence of being removed. But if the engine ran prior to the rebuild, then there's no reason to believe the afm is bad.

Was this car running prior to the rebuild?

02 is not a player in anyway.

Trail plugs on backwards could cause the problem. But you've already double checked that. Or lead wires where trail wire should be would cause problems. But you've already checked that.

Maybe a large air leak like the brake booster line off at the back of the engine might cause this.

Fuel injector grommets leaking air real bad might cause a bad idle but at revs it might not show up much at all.

Primary fuel injectors on secondays might cause the problem, but you'd have to work at it for that to happen. Or a fuel injector plug on the water thermo sensor might cause that......pretty hard to do though.

Last edited by HAILERS; 12-11-08 at 12:51 AM.
Old 12-11-08, 07:49 AM
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Hailers thats wrong about the thermo sensor i had no problem starting the engine but ehen it was running after it warmed up it would idle fine but when driving nomatter how much throttle i gave it, it would not go over around 3000k to 3500k i finally pin pointed it to be the thermo sensor after i replaced it the car went back to normal. the water thermo sensor give the ecu a reading of how much fuel to dump based on coolant temp if it is giving a bad reading it is going to cause the engine to load up on fuel and start spitting and sputtering, its not going to want to rev hardly at all.
Old 12-11-08, 09:06 AM
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WHat about fuel lines on backwards?

I would also send the injectors out to be cleaned! Cheap and easy!
Old 12-11-08, 09:07 AM
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How much free-play is in the throttle cable? Are you actually getting full throttle at the throttle body?
Old 12-11-08, 09:22 AM
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Here's what I wrote:" A disconnected water thermosensor on the back of the water pump housing will cause a difficult start if the weather is cool to cold. Once the engine warms up it won't effect anything because the ECU will default to 180*F temp i.e. normal operating temperature."

That's the way things work. Note the second word. Also see the jpg.

That said, I agree with you. If the plug on the sensor is making intermittent contact or any other part of that circuit making intermittent contact, I can see where the ECU would go slightly nuts trying to figure out if it was coming or going and what the resistance/temp is.

The second jpg was thrown in just in case anybody wants to know the part the water thermo sensor plays in the starting of the engine.
Attached Thumbnails Can't rev over 2k.-waterthermosensor.jpg   Can't rev over 2k.-graph2.jpg  
Old 12-11-08, 10:24 AM
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So, another curveball for the RX7 database.

Out of my last desperation move, i turned my rx7 on this morning. It turned on perfectly, was able to rev up freely past 3k without hesitations, and i'm sure if i let it warm up it would idle perfectly.

After about 20 seconds of confusion as to why my car was working i shut it off. Me being pissed and happy my car fixed itself, also the droning of the low coolant buzzer (haven't completely topped it off yet).

So my last thoughts as to why my car fixed itself. Bad gas? The car was sitting for months and months with no stabilizer in the fuel on less than half a tank.

But since i shut it off early, it is flooded. So once i finish topping off the coolant and make some slight adjustments, i will have my final word in this thread.


(SHORT VERSION) Old, bad gas ******* sucks.
Old 12-16-08, 09:38 PM
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So after 4 days of no power i am able to use the internet again, yay!

New fun issues to work out also.

Car starts up, does the whole rev between 2k-3k rpm, idles on its own that way. Let it run for a couple minutes, then the TMIC blew off, loose clamp. The car stalled instantly.

After looking around i saw a big glowing turbo manifold, sweet! Bright cherry red, was VERY hot. The car was also backfiring a lot.

Since i have a large streetport, i am assuming the super-heated turbo manifold was caused by running lean.

The TPS has not been adjusted yet, but i think letting the car sit for a little and getting tuned will be the best option rather than playing around with it.
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