Bogging/Popping until 2500 rpm

[framey]

Hi,
I\'m writing this in the hope someone will save me having to make the expensive journey over to the UK and it turns out to be something simple.
I have a 3rd gen (92) auto.
When I try and accelerate the car from low revs, it pops, stumbles and generally bogs down until I reach 2500 rpm when everything then seems normal. This happens hot or cold but is worse when warm. Boost seems normal. I have no mods and a standard ecu. I\'ve recently had the engine re-built and although I\'m not sure I had the same problem then, but I may of. If I did, it seems worse now. It has new plugs and recent magnacor leads. Checking under the bonnet everything looks ok, and in any case as the engine has been apart, I\'m sure it has been put together right - vacuum lines etc etc.

Sometime after a longish run, when I restart it it cuts out when pulling away/idling. Maybe something to do with a "cold start" system? It starts ok again after this.

Is there some significance in 2500 rpm?

HELP please!
Thanks

[Big Stu]

Has the engine been ported at all?? And do you have any mods on the car?

[framey]

No, no porting and no mods.

[gsb876]

Sounds like the ECU needs setting up properly ?

[Donato]

The ecu might need reset...

There is a procedure for resetting the ecu, cant remember it exactly, i think you have to disconnect the battery and hold down the brake pedal for 20 secs the reconnect the battery....might be wrong though...

[Big Stu]

http://www.mazdarotaryclub.com/forums/showthread.php?s=&threadid=11925&highlight=ecu+reset

Donato\'s right for the ECU reset.

Might be worth a go

[framey]

Hiya,
tried resetting the ECU some time ago - I seem to remember it made things better for a few mins.
I\'ll try it again  - just in case.

Anyone else know if 2500 rpm has any signifigance?
Thanks

[Ricco_04]

Clueless person responding...... :rolleyes:

Isnt 2,500rpm about the time that the first tubby comes online?

[Shark]

first tubby is spooling from the start and should be up to full boost between 2 and 2.5krpm.

2,500 rpm is roughly when the airpump kicks in.  You could just unplug it to see if it makes a difference but I can\'t see how it would.  
:confused:

[saxon]

funny! i have a 92 auto with no mods, apart from no cat exhaust and mine keeps doing the same thing from 1500 to about 2200 then clears. its been driving me nuts now for months, has cost me £600 with no improvement. been told it could be the idle control valve now, here we go again!!!

[clive]

Hiya,

Does the engine idle properly ?

If it\'s flutuating it could a vacum pipe, have a special look at the Map sensor.

The other one is, check that you have the injector wireing clips are on the right way round and that you havent got the primarys on the secondarys and vice versa.

[saxon]

hi,
the car idle varies but not constantly. one day it will be at 900, then the next 11 or 12. also while it is stuttering smoke pours out of the exhaust. If you feather the throttle it eventually goes. it never does this above 2000 to 2200 rpm. thanks for your help.

[TonyBlair]

Saxon, did you resolve the problem with your car?

The problem you\'ve described sounds similar to the problem I had; the bearings on the primary turbo were knackered. At idle it smoked, under load the smoke cleared.

Have you thought about getting it to a local specialist?

Cheers
Jon

[saxon]

has been to one and cost me quite a sum but to no avail. will hv to go again soon, when money allows!!!

[scooby_si]

who did you go to?
Si