No power until 5400 rpm
07-18-02, 04:09 AM
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No power until 5400 +/- rpm Need Help!
I own a 84 rx7 gs bone stock. I dont know what happened but right after I purchased it, the car wouldn't start. I probably messed with things I shouldn't have. The car only has 88,000 original miles on it. When I'm driving the only way I have any power is if I push in the clutch rev it to about 6500 rpm and drop the clutch. It runs out fine if it's not under load, but under load I have get it over 5400 +/- rpm for it to run out properly. It also bogs if I let off while accellerating, even if it's just the slightest amount. Anybody got any ideas?
Last edited by pk7tanner; 07-18-02 at 04:16 AM.
07-18-02, 04:14 AM
#2
"messed with things I shouldnt have"...Can you explain in detail a little better? Did you turn screws, move wires, play with hoses? Check your timing I guess just to get you started. Get a manual, it will tell you how, its a little different with two ignition coils in there...
~T.J.
~T.J.
07-18-02, 04:26 AM
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I turned the air mixture screw so much I dont have any idea where it should be and the accellerator cable a tad. The reason it wasn't starting ended up being fouled plugs. I have since changed them (no differance) and the car is also very hard to start when hot. And it also smells like it's running hot, but temp gauge isn't reading hot. This car may have also sat for awhile. It had 41k miles in 87. I also have a Chltn.&Hyns. manuals.
07-18-02, 04:30 AM
#4
Ok, the mixture screw should be about 3 1/2 turn out counter-clockwise (I think). This could also be your hard hot starting problem, if the mixture is too rich, it could be flooding it out (once again, I think). As far as the accelerator cable, I have no idea, sorry. It sitting for a while isint a great thing either, but I dont feel well enough to go into all that, Im sick 
.
~T.J.
PS - Rotarys run hotter than piston engines too, so that may be your "hot smell".
.~T.J.
PS - Rotarys run hotter than piston engines too, so that may be your "hot smell".
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08-03-02, 12:49 AM
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I bet you may have had a corner triangle in the motor go out. Does it seem like the motor is missing? I had this happen and it will still even appaer to idle fin but will run only basically on one rotor untill about 4k and then reseal and run on both. It felt exactly like what your explaining.
CJG
CJG
08-03-02, 12:53 AM
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Can't help myself from asking... An 84 with only 88k on it and this many problems?!
Dunno if this helps, but your secondaries open up under load around 5000+ RPMs... Maybe your primaries are messed up (dunno how that can really happen)?
Dunno if this helps, but your secondaries open up under load around 5000+ RPMs... Maybe your primaries are messed up (dunno how that can really happen)?
08-03-02, 02:14 AM
#11
have you checked your timing and, if you messed with the wires, is your leading and trailing coils hooked up to the dizzy properly. the coil towards the front of the car is trailing. are the wires going from the dizzy to the plugs right? are you positive? the mixture screw should be tightened until the motor starts to cut out and miss then turned back a half a turn or until the engine's idle smooths out. if the wires are right then its time for a carb rebuild as i believe the carb is either flooding, the secondaries are stuck open, or the floats are stuck. try peejays method off giving the carb a solid whack on top to try and free them. of course don't beat the schiznit out of it. that should free the floats if they are stuck. but this would seem odd since it only does it under load. if it was flooding it should stumble any time. hmmmmmm. sounds like ignition. hell, try some of these ideas, see where you end up.
08-03-02, 05:31 PM
#12
Re: No power until 5400 +/- rpm Need Help!
Originally posted by pk7tanner
I own a 84 rx7 gs bone stock. I dont know what happened but right after I purchased it, the car wouldn't start. I probably messed with things I shouldn't have.
I own a 84 rx7 gs bone stock. I dont know what happened but right after I purchased it, the car wouldn't start. I probably messed with things I shouldn't have.
Are you saying that it was running fine before you bought it? I'm asking only becuase it would be useful to know if you started out with the car in a decent running condition ... how and where did it idle? did it pull smoothly?
Anyway, yeah, get a manual and make sure all the ignition wires are hooked up correctly. I don't know how much you know and how much you don't know about rotaries, so if I say something simple ... it's not because I'm trying to imply that you are dumb or something (not being a wiseass) ...
Do like what jeremy and rotortuner said ... reset the idle mixture screw to around 3.5 turns and check the timing and make sure that's in order ...
If the car starts to act normal, then you know you're on the right track. It does sound like carbie problems, but it could be something else. Every little bit of info counts, try to talk us through first and second gear in your car as it's acting now.
08-03-02, 07:23 PM
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ok, It runs like it's a normal engine does when its cold eg. very little power. In 1st gear I actually need to the rpm to 6k, then boom it takes off. In 2nd - 5th it deos the same thing but I it run out good after I hit 5400. I've changed the plugs and reset the air mixture to 3.5 turns but it's still the same. It crazy! I dont recall it running bad prior to buying it, but I wasn't driving it I was a passenger (I know, how stupid of me). I got a pretty good deal on it I thought so I didn't really take time to think right. I got for $1250 and checked the miles on carfax they're real, 88k original. Everything else about the is like new still, except for the A/C.
Last edited by pk7tanner; 08-03-02 at 07:47 PM.
08-04-02, 02:12 PM
#15
Originally posted by pk7tanner
Anymore info for me diabolical1?
Anymore info for me diabolical1?
i'd love to try to help out some more, but i don't want to frustrate you any further by continuing to ask for more info ... but i'm still not sure how the car won't do anything between idle and 6000 RPM.
i'm going to assume that everything that myself and the others have suggested (ignition, etc.) are confirmed to be in order. so i will move on to exploring other things ...
how does it idle? where does it idle? is it smooth or rough? does the car produce any dark smoke until it starts to make the power you describe at 6000 RPM?
do you know what kind of fuel pump is in it? i recall you saying that you changed the plugs, check to see what they reveal (rich, etc.). what about the cap and rotor, did you change those as well?
in your original post, when you said that you messed with things you shouldn't have messed with, what exactly are some of those things?
as long as we get a clear enough picture, even if i turn out to be useless, i'm sure one of the guys here will be able to provide you with some good advice. just continue to have patience ...
08-05-02, 03:43 PM
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Guys i think he may have worse problems than what we are thinkning. Do you have to like rev the thing up and slip the clutch raely bad just to get it going forward? Like if you let out the clutch to fast will it die?
CJG
CJG
08-07-02, 06:58 AM
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Try unhooking the exhaust right after the manifold. Just loosen the nuts a bit and get a 1/4 inch seperation.
This is to see if your cats are clogged up.
I can't figure any other one single thing that would make your car do this.
It's very unlikely you've managed to lean your carb so much that you have zero load power.
It's not like you stuck in smaller main jets!
Another carb possibility is that you have a blockage located at one of the primary (main jets in the fuel bowls). This would coincide with the RPM range where the retaining spring on the secondary shaft is lifted, allowing them to open when promted by vacuum.
Something else coming to mind as an ever-so-remote possibility is that your return line is blocked. If the flow was impeded (I dunno how!), then your carb would see too much pressure during low consumption, being basically overwhelmed with fuel flow. This would mean that the emulsion tubes would'nt be exposed until the higher RPMs when you were consuming enough fuel. Then you would be in a better mixture.
I dunno...seems verrry stretched on thatt one!
...But we're thinking about it for ya!
Keep us updated; We'll all get it.
This is to see if your cats are clogged up.
I can't figure any other one single thing that would make your car do this.
It's very unlikely you've managed to lean your carb so much that you have zero load power.
It's not like you stuck in smaller main jets!
Another carb possibility is that you have a blockage located at one of the primary (main jets in the fuel bowls). This would coincide with the RPM range where the retaining spring on the secondary shaft is lifted, allowing them to open when promted by vacuum.
Something else coming to mind as an ever-so-remote possibility is that your return line is blocked. If the flow was impeded (I dunno how!), then your carb would see too much pressure during low consumption, being basically overwhelmed with fuel flow. This would mean that the emulsion tubes would'nt be exposed until the higher RPMs when you were consuming enough fuel. Then you would be in a better mixture.
I dunno...seems verrry stretched on thatt one!
...But we're thinking about it for ya!
Keep us updated; We'll all get it.
08-09-02, 06:52 AM
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I dont know anything yet because I haven't been able to get somewhere that I would feel safe taking the carb apart (ie. no gravel ect.) and I'm getting the clutch done. I just wanted to say you guys are awesome, I have never gotten so much good and thoughtful info from complete strangers in my life. Too bad there aren't more people like you guys in this world. But I know it's not the cat, there plenty of exhaust presure. I just have my fingures crossed that it's the primary jets. Thanks for all your help.
08-09-02, 07:40 AM
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Another thought is water in the fuel tank. Open the drain plug (have a pan under the plug to catch the fuel) and see what comes out. I had a similar engine running problem and water, = rust & corrosion, clogged the carb fuel jets. I am currently installing another carb as the first one was so damaged it nearly beyond repair.
If water is found, you will need to do a complete cleaning and possibly refurbish the fuel tank. Check the fuel filter for rust powder. At least change out the fuel filter.
Best regards,
THC
If water is found, you will need to do a complete cleaning and possibly refurbish the fuel tank. Check the fuel filter for rust powder. At least change out the fuel filter.
Best regards,
THC
08-22-02, 05:48 AM
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Hey guys Ifinally got my car back. Now that the clutch is fixxed I can tell you a little bit more accurately what's happing. I am leaning towards the primary jets being the problem. The car still runsout poorly until 5-6K rpm. The problem also occurs when I let off (while at the high rpm) the gas a little and then try to accelerate, but it seems like if (after getting the R's up) I let off the gas all the way, then hit the gas, the car will still runout good.
