10th AE major issues! Spits and sputters
 

Hi all!
As the title says I have a 1988 RX7 turbo 2 10th anniversary edition... What a mouthful! I just bought it from the original owner and I am having some major issues! :(. As soon as I try to give it any throttle at all.... The engine cuts in and out and spits and sputters. I had a eagle talon that once did something very similar when it blew the intercooler pipe off. I pulled the intercooler and verified good connections and clamps.... Here is what I can tell you about the car I bought it from the original owner. It's is almost 100% bone stock. The owner says it has a factory upgraded exhaust from cat back that was designed by HKS. He said it was a $1600.00 option in 1988. It also has an upgraded downpipe with NO PRE CAT. He said the oem pipe rusted so he got this put on. I realize the car will hit fuel cut, but I can't even get it to zero on the gauge it's running that poorly. It has new plugs, wires, fuel pump, and filter. All new fluids. The motor won't rev hardly at all when it's like this and it's almost impossible to drive. If you turn the car off then back on, it will rev freely and drive ok for a little then back to the same old crap. I also noticed after I started it once the tach gauge stop working??? I turned the car off checked a few things under the good and hooked my batter charger up to it. When I started it back up in 5 min, the Tach was working again?!? I would yell limp mode, but my research tells me the s4 do not have such a thing. That's what it feels like to me. When the car has its temporary moments of running good, the motor feels strong and the turbo spools fine. Compression test was done last year and yield 106(F) 101(R). I am a loooooong time Dsm or Mitsubishi guy. And from my experience with them this seems like it's a sensor/ wire issue. I just need some help from the people that have the know how on these cars
Thanks guys, any help is greatly appreciated.

Tach signal comes off the trailing coil, you could have a failing coil on your hands or there could be excessive corrosion where the coils meet the chassis (they ground through their mounting points). I would first start by cleaning those up. My 10ae also would periodically lose tach and ever since I cleaned up the coil mounts I haven't had a problem since.

I will clean up some of the grounds on the car. Possibly fuel filter? Are these cara picky whine it comes to pressure in the rail? I also thought maybe TPS

"10th AE" will suffice. Everyone will know that it is an '88, turbo, and white.

Since re-starting the car seems to help, it's probably because the car runs a different fuel/timing map for the first 30 seconds.

Tach operation can become a little intermittent. Not super common, but it happens. I suggest attacking that later.

Here's a few suggestions:

1. Check timing with the idle under 1000 rpm. Check the plug wires are on the correct plugs. Trailings on top, Leadings on bottom. #1 rotor is in front, #2 is rear.

2. Throttle position sensor. Test the sensor by itself in open/closed position as well for any dead spots along the sweep.

3. These cars are very sensitive to vacuum leaks. Check for cracked plastics, vacuum hoses,etc with carb cleaner. A lot of them will not be visible, but will react to a combustible.

4. They're not too picky about fuel pressure. I doubt you have to worry about it unless you installed something rediculously large or small. What pump was installed?

RXspeed16,
Thanks for the head up on the 10th AE. The info you gave will be very helpful in diagnosing this issue. The fuel pump was replaced by the original owner, but I think he used a stock replacement for that. The car has been stored indoor/heated for the last few years with only a few miles put on. Oil was changed every 6months and started 2-3 times a week. Don't know if that info is needed. Also the car dose have 172,000 on the stock motor..... Like I said compression IS amazingly good from what I am reading for the milage. But the owner was meticulous with oil/coolant changes. He said he has been using Mobil one for most of the life of the car.

I am actually considering just upgrading the entire ignition system now. Any suggestions?

No problem. :icon_tup: It's all about getting the right keywords to search for. I'll put you on information overload and you can get around to things as you have time. :D

The stock FC ignition system is very stout and works pretty well until you're up in the 350+ hp range. New plugs and wires are usually enough to get it back into tip-top shape.

When the fuel pump was changed, did they also do the fuel filter in the engine bay? Driver's side lower firewall. It can be restricting flow which won't be apparent at low loads.

If you're not building boost, I'd look at the turbo piping especially the connection between the turbo outlet and the charge pipe. That short rubber coupler can be difficult to seat properly. Next would be building a boost tester to pressurize the whole system and search for leaks.

If you suspect the turbo, check it for shaft play by trying to move the compressor blade. A little side-to-side movement is acceptable as long as it doesn't touch the housing. In-and-out play is bad, though.

Also, the electrical ground system in these cars can cause major hiccups as well. This page was put together by a member here with a lot of experience and very helpful write-ups, including the grounding system.The Second Generation Mazda RX-7

I had a similiar issue with my 10th ann it turned out to be the TPS

dude thank you for that link that just answered hella questions i had

You should probably check for any vacuum leaks, check TPS, check the wiring, could be a emissions control system issue if anything.

sounds like a timing issue, i had a bad trailering coil pack that it wouldnt give me the rpms at times and something it would. and when id didnt work i would get terrible power output...but then again it was NA at the time...