I have a 1988 convertible RX-7(non turbo) and have had it for a couple of years now. It has run perfectly up until now. A few years ago I had another mechanic look at it because it wouldn't go up to the speed it should it certain gears. The symtom was that it felt like it was running out of gas when it was in gear. Of course that wasn't the problem because it was a full tank.
The other mechanic though it was my catalytic converter and said it was plugged up.
Ok so i got new cats on it now and the problem still exsists.
My mechanic thought it needed a new computer chip which he ordered and that didn't fix the issue either. So then he changed the fuel filter and pump and still the same result.
Then he changed out the plugs and still same result.
We are at are wits end. Does anybody have any idea what could be causing this problem?
THis mostly happens in gear 2-4. Once I get it to 5 it is ok but to get there is a hassle. Something is wrong and maybe somebody has had this simlar problem.
Can anybody give us some ideas of what it could be?
Thanks in advance,
Chris--northern california

 

5th and 6th ports are stuck closed?
That is just a stab in the dark... I've only had T2s. But I've heard if they get stuck closed it can cause problems like this.

Also, maybe the TPS is out of adjustment, o2 sensor is bad...?

 

Does it seem dependent on RPM also? Does the problem not exist when in neutral?

 

Has the car always been manual? If not, how was the swap done, I mean, what was used/changed? Does it have the auto ECU?


Spec.

 

Maybe some dirty old injectors? Check the engines compression.

 

First, get a new mechanic. The order in which he's done things, and some of the things he's done, is absolutely retarded.

First thing I would check are the 5th/6th ports, but that's assuming that your car is still pulling up top, but is not pulling as hard.

If your car is literally hitting a wall and not exceeding a certain rpm while in gear (5th), then we need to know what the engine speed is. In a lot of cases where the car isn't exceeding a certain rpm, it's usually caused by faulty secondary injectors.

 

maybe you need to clean you grounds

 

limp mode? you need to give us RPM specs on when you are shifting and stuff, or bring the car to me.lol

 

Could be corrosion on the terminals of the TPS plug... But then the symptoms would be in every gear. That's the part that gets me... Is the problem really only in certain gears? We need more info on this problem.

 

When you say the cats were replaced, that includes the 2 precats? If not, inspect them for damage too. I've had a cat plug on me, and it absolutely killed top end power. It took forever to reach redline.

If not that, my vote is for low compression or a fuel delivery problem. The pump and filter have been swapped, so that only leaves the injectors and the FPR. Maybe the secondaries aren't coming online at 3800, and you're managing to just barely accelerate on primaries alone. You can test them for power with a multimeter.

And if no one has done it already, pull engine codes: http://www.teamfc3s.org/info/article...odes/main.html


No such thing as limp mode on an S4.

No such thing as an auto ECU either. All stock ECUs can be used with either transmission type; there are just pins that are unused when run on a manual car.

I drove my vert around for years with the aux. ports stuck closed, but it was never like the OP describes. It still went up to redline easily; it just lacked some of the power it should have had. I never knew the difference until I rigged the ports to open electronically, since backpressure wasn't working.

 

It is a stick and it has always been a stick. The clutch is only like a year old.
Great idea about the precats. I don't know if the guy did anything with them.
Thanks everybody for some insight to this. This problem does not exsist in neutral only like in 2,3, and 4th. Once I get to 5th it seems to be ok.

 

the mechanic is just guessing and throwing parts at it. i hope you are not paying him for all the wrong diagnostics.

 

Uhmmmm--maybe check the fuel pressure regulator on the fuel rail. It's vacuum dependent and you may have a bad one, not maintaining fuel pressure as the rpm's go up.

 

the mechanic should have performed the tune up first, then started on other things.
Fuel pressure would be a good, easy place to start.

You said you replaced "cats", which ones, and how many did you change?

 

I would look into grounds/fuel delivery system. Your 5/6th ports could also be stuck, check if they move freely.

http://www.aaroncake.net/RX-7/grounding.htm

 

I my be talkin out of my *** on this one, but check on how clean your socc on your fuel pump!!! Like I said I might be talkin out my *** but I kept hittin a wall in 4th gettin stucc at 4500 and in 5th. My fuel level sensor floater was bad after I replaced it and cleaned the socc (Screen filter) I never had that problem again only I dont pull in the now that I have a R&B Header I have to downshift to 4th to pull... So needless to say I'm turbochargin my 6 port till I do my swap... Than a rebuild on the 6 port into a Miata soon to come in the next year hopefully!!!

 

better check your sensor, TPS!!!!