Eta Stair Step Acceleration?

[BMW BMXER]

I have heard a few people commenting on this before. It feels like my car surges when my foots down, hard* acceleration, slightly moderate for half an instant, then hard acceleration again.

I have also heard the chips help this problem. I am getting a Jim C in a few weeks and was just wondering if anyone else's eta does this and whether or not a chip made the problem less severe or worse. Or plain knows why it happens.



*I know, I know...

[Sean]

Our 87' 325 has the same problem, even after the chip.

And my car does it now too - didn't before it sat for almost a year. I was pretty bummed. :|

[James Crivellone]

mine has always done it while cold, once its warmed up it runs great though.

[BMW BMXER]

No ideas as to why though eh?

[schnitzer teil-jäger]

Welcome to eta.

early motronic. anything that gets it out of whack (O2 sensor, temp sensor, bad wires, etc.) will make it jump from one step on the program to the other step. think of it as a phone camera. now think of the later motronic as a standard digital 2 meg camera. and the newer stuff as a professional digital photo camera.

so unless you are very very lucky on the witch hunt. you may replace every sensor and swithc and still have the problem because of a poor risistance on the wire somewhere.

w

[Old'n'Slow]

Etas are set up with lean operation for high MPG. This causes a somewhat lumpy and non-linear acceleration. I think a different FPR with higher pressure combined with a chip along with clean injectors and intake valves would go along way to helping. I haven't fooled around with this, but I've got a Super Eta and it's not quite as bad...

[Ryan Stewart]

Mine did it until I got the Conforti chip, was gone after that.

[BMW BMXER]

I am looking forward to the chip people say it makes a big diff on the eta.

[JoeP]

My 87 does it too, but only after it warmes up. I'm hoping it's the o2 sensor, which I plan to replace in a couple weeks. By the way, I'm new here and I have to say this is a great forum! Keep up the good work.

[bwanac]

My car only does it on uphills.

When I had JC chip in I guess it did dissapear, never realized that.

Welcome a"board" JoeP! :up: Lame, I know.

[ryan_george]

You can buy my MarkD eta chip 8)

[Marvin_Hecht]

Hey...I know I am raising an old thread from the sleeping grave..but I may have the same problem. When I accelerate hard there seems to be some sort of hesitation and the tach jumps a little.

I am also thinking of getting a chip for my eta, either the Jim Conforti,
the Mark D, or an ACS (Ac Schnitzer) chip... so did the chip solve your
problem or make it less bad?

[///M Powered]

Same problem here, and I've run out of ideas. ( wish I could chip my car :? )

[BMW BMXER]

Thought you swapped?

Chip made my problem virtually dissapear.

[Marvin_Hecht]

Well I got a chip in my car and all I can say is YYEEEEEEEEEHHHHH HAAAAAAAAAWWWWWWW. I feel like the Dukes of Hazzard...now
I'm doing like 90 mph without realizing it.

The guy who installed my chip drove my car and found that my stairstep acceleration is due to a failing center driveshaft bearing - which may also be causing the tach to jump....in any case the chip helps to smooth, liven and perk up the engine .. it even ROARS now between 3.5-4.0 I can't believe it, jeepers..... 19.5 years without a chip in this car....I'm used to waiting when hitting the pedal.....no more. No I just need a diff to get the revs up into that sweet spot between 3.5 and 4.5 as part of my normal driving....