DashKits.net

i posted a while back that my 1993 AUTO Rx7 cuts out when driving through traffic slowly when
it reaches 2K...
THEN you have to give it alot of throttle and it picks up again, and if it shifts and puts it below 2K RPM it'll do it again.

VERY FRUSTRATING!

It does it maybe once every 3 or 4 days.
HOWEVER, after playing around last nite, i
realize it
ONLY DOES IT WHEN THE A/C or HEAT is on!

Whats the deal!?
What could be the problem (and the solution?)

Someone wants to buy my car and i want it in perfect shape when it's sold.

again, it is AWESOME with the air isn't on- runs perfect.

But it cuts out badly at 2K rpm (in the 1500-2000RPM range)
and i realized now, that its due to the air being on.

HELP !

thanks!

AJ

Sales@DashKits.net or just post here

PhatManBUD

hey guess who, haha

DashKits.net

YEP, its me

the RX7 runs great, but
for some reason kicking the air on jacks something up

anyone anyone?

Toadman

There is an ECU replacement recall on low idling/stalling with AC on for 93's. Contact Mazda Customer Assistance at 800-222-5500 with your VIN to see if it applies. Does the idle drop when the A/C clutch engages? How does the heater get involved?

DashKits.net

idle DOES seem to drop low, YES
but it seems like the car drives the same
(the RPMS and shifting are the same whether the AC is on or not)

However, when the AC is on, the car stumbles badly from 1500-2000 RPM.

thanks for the info, i will contact them.

anyone else have knowledge of this?

thanks!

bajaman

This is one of the classic "grounding" problems, too.
My car started doing the exact same thing early this summer, I put an extra ground on the battery to the chassis and on the UIM to the chassis and it completely solved the problem. Try this easy and cheap fix, it can't hurt!

DashKits.net

whats the UIM?

the car has had an alarm put on and the battery connections are a bit odd

again the UIM is what?

striker

upper intake manifold. thingy at the top of the engine just beside the throttle body.

DashKits.net

Gotcha

thanks guys!
ill try this for sure!

Any other experiences?

bajaman

Oh....sorry! UIM is Upper Intake Manifold.

You can connect a ground strap wire available at any auto parts store to a good grounding point on the chassis and then to the UIM. Here is a pic of what I did, in addition to adding another big-*** ground wire to the negative terminal of the battery.

ArchangelX

Can anyone explain to me how ground sorts out problems like this? Sorry..I'm a newb.

bajaman

Essentially it makes the car's Electronic Control Unit more stable, less prone to incorrectly read an erroneous input and attempt to correct.
A car, or any other machine for that matter, is a hotbed of stray electrical signals of varying frequencies, essentially creating "noise" that sensitive control modules can misinterpret.

At work our CNC milling machines act really weird if someone fires up an arc welder, even if it is hundreds of feet away! The high frequency "noise" generated by the welder is seen as a feedback signal from the servo units and drives by the control, and the control reacts to it.

DashKits.net

thanks!
this help is greatly appreciated and needed!

AJ

DashKits.net

i bought the grounding straps... (crosses fingers)

any other solutions if this isn't it (besides running it into the Mississippi River (only 5 miles from here)