[Jared S]

So a new problem has started on my '94 aero. I've been having problems where the rpms will go crazy between shifts or just when letting off the gas at rpms over 2500 rpm. The weather has started to get cold here in Canada. It's currently around -8 degrees celsius. The aero refuses to go over 3000 rpm, regardless of how soft or hard I am on the throttle. It will just sit at 3000 rpm like it is hitting an ignition rev limiter and it's not violent at all. The only thing I can think of is the DI cassette. Is this a symptom of a failing DI? Do failing DI's throw a CEL. I find it strange that with all these little problems I'm having the CEL has not come on once. What the hell is the point of the CEL if it doesn't even come on when something is working incorrectly? I know the DI was replaced at 20,000 mile and I know it was replaced one other time but I'm not sure of the mileage. It may have been around 70,000 miles. My car currently has 123,000 miles on it. I bought this car because I wanted something reliable and nice to drive over my modified c900. Turns out its causing more of a headache than the highly modified c900 ever did, and I've only been driving for 3 weeks. Any help would be great!!!

 

[justin.graeff]

Yeah, I had this problem in my Honda once. I would rev it up, it'd go up to about 4k, then just stop, like it was hitting a wall. My friend suggest doing a general clean out of the engine. Basically I used some sea foam and what not. Anyway, it didn't work. So, then he suggest maybe my exhaust was clogged. A few days later, I cut that thing off, and lole and behold, freed that sucker up! I don't know about you, but you should at least consider it.

 

[boxman]

try changing the crank angle sensor, if it is breaking down at 3000 rpm it would feel like hitting the rev limiter, this could be due to the very low ambiant temp'

 

[Jared S]

I've got a spare DI cassette that I'll be trying today. I've got my fingers crossed!! I'll post my results as soon as I can.

 

[Jared S]

I tried another DI cassette and that did the trick. The idle is also smoother now. The previous owners sold it at exactly the right time I guess.

 

[Jared S]

Well it's not the DI cassette causing the problem. It no refuses to go over 2000 rpm. I believe it's the crank sensor. If I I am driving at an rpm below 2000 rpm then I drop a gear and just let the clutch out without stepping on the throttle, the tach will just drop to zero untill the car slows down to a speed that gives an rpm that's below 2000 rpm, then it will come back to life. To me this points to the cranks sensor. It seems like the crank sensor is just failing to output a signal at an rpm above 2000 rpm. I checked the resistance between pins 1 and 2 on the crank sensor and I got a reading of 610 ohms, which is within the 540 +- 50 ohms. I'm thinking about taking the sensor out to see if it is just dirty before I go ahead and order one.