Josepi

Here goes, driving into work today I noticed a small hesitation; very mild bucking in 5th gear from 2.5Krpm to 3.5Krpm. When it starts happening, if I throttle it more, it will just continue to buck more. However, if I let off the gas completely and push back on it doesn't do it! It idles fine at 750ish, I have no problem cutting on all the accessories.

If I drop a gear into 4th and punch it, it goes as normal, boost is good. All the problems are happening without the boost. If I hit boost while its acting up, it just bucks worse!

I know its not tranny related, it'll run fine any other time. Just when its acting up, its a pain in my ***, had the car for 3 weeks, making my first payment today, wouldn't it suck if it died!?!!


Any ideas? TIA

The Ace

Just guessing now: could it be the notorious 3500 rpm hessitation of the 2nd gens ? Since you are saying that it occurs at about 3-3,5K rpm, then you should check the secondaries, and make sure all your grounds are still good. Check the two grounds in the engine bay, and the grounds of the ECU.

Anyone anything else ?

Josepi

Well it normally starts below 3k, around 2.5-2.7K most notably. I don't think its the 3800 rpm problem, grounds maybe. Could this be a fuel issue? I have the mysterious problem of sometimes losing power going around left turns (with alot of force ) but this is happening when i'm going in a straight line...

Anything would be nice, I guess the grounds would be a good start. Would the injectors going bad have anything to do with it? When do the secondaries come into play @ what rpm?

TIA,

Joe

91 TII-getting a cold
83 GSL-in a coma

13BAce

Does your check engine light come on when the problem occurs?

Josepi

Not that I have noticed...one that note, when I turn the key and get all my idiot lights, my engine light isn't coming on, all the others are though (this is sporadic, sometimes my ABS light doesn't come on...) does this mean there are stored codes?

13BAce

It's possible that your air flow meter could be a little loose. If it's not held tightly to the turbo inlet duct and moves alot you could get the problem you're describing.

Josepi

Thanks! I'll definately be checking that once I get home today, i'll pay more attention to see if it acts up after bumps (wouldn't it then be more likely to jiggle around and leak?) Anything else you think I should swing my monkey hands at?

PraxRX7

Check your engine codes....it might tell you what is wrong.

Josepi

Going to be checking codes, AFM, and grounds, I wish I could take the day off to do all this

vaughnc

Had something similar. RPM range or gear didn't matter and I lost all power for about 5-15 seconds.

Turned out the intake was cracked and and it was fooling the ECU into a lean or rich condition. The O2 sensors were picking up this fake condition. When the ECU tried to compensate, I think it was cutting or sevearly limiting air and/or fuel.

Error codes were both O2 sensors (turbo only) and thermo.

Josepi

These are more like half second burps, the more I let it buck, the more it will buck, if I let it smooth out, it normally smooths out

vaughnc

... anyway mazcare repaired the cracks and replaced the O2 sensors (since I had no clue how many miles were on them). Problem solved.

gorockrx

Have you checked your throttle cable freeplay measurement? Mine did the same thing cause when they get older and you put your foot in them a lot the cable actually stretches a bit and makes it loose. Every once in a while gotta tighten it back into spec.
This could be a possible problem along with the air meter. Also get a cable ground from autozone (4 ga) and install on the rear engine lift bracket to the firewall (scrape the paint good) and put a good 2ga batt ground cable on the battery. My car works great now....
Hope that helps.

Erik

OMG DUUUUUDE...i just bought a 91 T2 this weekend and now have the SAME problem. it got worse and worse on the way home...so maybe the AFM did come loose and jsut got looser and looser...


...this weekend i purchased a very nice 91T2. I went, test drove it, everything seemed fine. Compression was strong, turbo was rebuilt w/ported wastegate to cut down on the boost creep from the present mods. its been in storage for the past 2 years. sooooo, i test drove it...seemed in great condition.
i live many hours away though and on the way home the car started to turn to sh*t! it would hesitate and buck under differnt rpm ranges, and sometimes different lights on the idiot guage cluster would come on (antilock, check engine, clock would go on/off). for the whole trip (15 hours) the car got worse. during stops to get food/fuel i'd check to see if anything was going on under the hood...all the silicone hoses seemed to be on corretly...i didn't see any other things that had popped off causing a boost leak. it finally got to a point where if i had the car in neutral in a parking lot, i would just rev it free and the tach wouldn't go over 2K...if you floor it, it just seemed to bog. i DID "manage" to make it home...but damn, not having any power sucks...

here are some guesses i had on whats wrong...

TPS- might either need adjusting or new (since the instrument lights were going on i thought this might have something to do with it. would me hesistation in neutral be caused by this?

DIRTY FUEL FILTER- since the car was in storage, my guess is it wasn't used to so much fuel or had a partly clogged fuel filter. i guess that would cause hesitation

DIRTY FUEL INJECTORS- on my trip home i dumped in a bottle of injector cleaner but it didn't seem to make a difference...

VACUUM/BOOST LEAK- i didn't see anyone out of order...but i'm used to looking at my other n/a engine...so i'm not as in tune with where stuff is

Josepi

Erik! You finally got your TII! Same **** as mine too sick

What color is it?

Josepi

Erik, the idiot light blink could be the classic idiot clock problem (solder oh my!).

Sounds like you got the problem that vaughnc had. Mine while doing that minibuck, I can put into neutral and rev it and it works fine, maybe its the bumps, or hasnt progressed to the same as yours. Who knows...

Jahoo88

I had a problem similar to yours erik. One morning i took the car out and it wouldnt rev past 1.5 - 2 k rpm. This was right after i switched the tps. Turned it off and worked the tps through the ful range of motion. Turned it back on and problem was gone but i have no clue if i fixed it or if it fixed itself.

Erik

yeah, it was weird...earlier in my 15 hour drive home i could rev it in neutral and it would be ok...theeeeen like 3 hours later it would rev with hesitation in neutral. finally at the end of the trip it wouldn't rev over 2K.

i guess i'll go pull off the AFM hose and intake and **** and see if everything looks ok.

let me know if you get the problem fixed

oh, and the car is red

13BAce

Let me know what you find. Most of the other possible causes would give a code from the ECU.

Greys 10th

I have a question, how do you check your engine codes on the rx7? Mine is a 88 TII if the year and model matter. my check engine light isn't coming on..but since ya'll are talking about it i thought id ask. plus does it store codes or anything like that?

Erik congrads on the TII purchase...put a pick of it up..i love looking at TIIs'
thanks..later

13BAce

Check out http://www.teamfc3s.org/info/article...odes/main.html .

fong

iTrader: (77)

hi, guys, I have the same problem with my 7.
I did the turbo conversion on my n/a, with a 90 j-spec in it now.
for some reason, the check engine light comes on in about 10 minutes or exceed 60 mph, at normal temp. I have checked my TPS, changed O2 sensor, but light still comes on. one of my friend checked the code(I don't know how he did it), then he told me that was O2 problem, that is why I changed the O2 sensor, but the light still on.

hey,

RETed

Get a tune up...
Change spark plugs, spark plug wires, check timing, etc.



-Ted