Oh, and another thing that might help some rotorhead here to understand:
It snowy and shitty weather here now, so - when i'm driving on really slippery snow, i can give full throttle and burn like crazy, - because (i think) i don't get any boost since there is no resistance to the wheels.

Will this help to isolate the problem? It's gotta be turbo-related..

 

i had the same problem on my 87 t2, turns out it was the fuel pump. more than likely that is your problem, you described the problem i had with mine exactly.

 

Clogged fuel fliter???
I'd check that, along with the fuel pump.
That's where I woudl start, forget all the electronics and grounding issues, start with the basics first.

Wanna hear somesthing interesting? I had a very similar problem a few months back... every time the turbo would spool up the car would be on its face, and make a VERY strange sucking noise, untill I let it idle, then it would dissappear untill I gave it gas again.
Turned out it was my air intake hose from the air filter collapsing on itself!!!

 

Bump

 

Checked the fuel system yet??? Guaranteed that's what it is.
Let us know....

 

I will check it out, but we measured the fuel pump pressure right after the rebuild, and it was completely in spec. The fuel filter...? I don't know. Will check it out.

So stupid that it's christmas, everybody is closed etc. but will get it soon.

 

Have you tried replacing the throttle position sensor(TPS)?? when i drove mine home it did that.......it did it at a steady speed sometimes to tho so idk

 

I'm amazed that no one has told him to check for error codes.


http://www.1300cc.com/howto/how2/codes.html


TPS adjustment:

http://fc3spro.com/TECH/HOWTO/TPS/tps.html


If you don't have an FSM, you can download a scanned version, viewable in .pdf (you'll need Adobe Acrobat Reader) from:

http://www.iluvmyrx7.com/2nd_gen_manuals.htm

 

I would check the tps, check your injector grounds, get your injectors flow tested. This type of problem can sometimes be caused by clogged/leaking fuel injectors in cold weather... is it still hard for you to start your car? Fuel filter as mentioned above could also cause problems

 

I doubt it's the injectors, cause we quadrouple-checked them when we installed them, and the car starts at ONCE when I turn the key, even in -20 C.

I will check for error codes, thank you very much.

 

Well, whatever the problem is, I sure as hell would like to know what it was once you get it figured out.

I didn't even know you could start a rotary at that temp.

If I woke up and looked at the thermometer and it read a negative anything..... I'd call in to work and go back to sleep.

 

you may have checked the fuel pressure, and it may show in spec, but that doesn't always mean the fuel pump is working properly. did you check the fuel pressure at idle? things might change when you go down the road you know. you should just swap in somebody's fuel pump you know that works to verify whether or not it's the fuel pump. the problem you describe was just like the problem i had on my 87 t2. the car would drive ok for awhile, then it would start getting worse by bucking/stalling and weird throttle response. because how can you be %100 sure just by checking the fuel pressure at idle?

 

another item that is a easy fix that can cause this is the O2 sensor, easy to check and replace if needed.

 

Well..... before I sent my injectors for flow testing/blueprinting/rebuilding I had the same problem. The car would start right up but in cold weather whenever I get on the throttle the car would start to buckle and jerk. Just a suggestiong though... er.. also before I got my injectors rebuilt, it would work alright in warm weather and it would flood. Just letting you know... but then.. you might not have the same symptoms. But I would first check the TPS

 

We checked the fuel pressure at idle, when driving w/ no boost, and with boost. It was spec all the time.

The injectors are not clogged, since I can drive for 20 minutes sometimes without any symptoms at all.

It's wierd, it has to be something electronic which - when triggered - tune down the car extremely.

I know many of you think I have the same symptoms you had once, but it's hard to describe actually - but I can tell that some of you had a totally different problem.

I WILL get to the bottom of this, and let you all know what the problem actually was. Myself, I'm betting on the TPS.

Sincerely

 

bump

 

have you checked for error codes and measured voltages at the ecu yet? no? then stop bumping and go do them

 

Bump bump.

Ok, I've checked for error codes, and a whole lot came up - mostly because of broken wires etc. So, step by step the wires were fixed, but one error code remained.

The Oil Metering Pump? Does this sound logical to anyone here?

Second solution: I was tipped by a mazda-dude that the pop-off disrupts the .. hmm.. AFM? (The sensor right behond the air filter). Could this be right?

Third: I removed the air pump. Could this have anything to do with it?

Any rotorheads who want to throw in their .02?

Thanx

 

1: The oil metering pump not working on a Series 5 causes the car to go into limp mode. Is your car a S4 or S5?

2: The stock pop off valve should not disrupt the AFM.

3:When you removed the air pump did you also gut your cats or replace them with a straight pipe?

James

 

it's an s5, s4s don't have the electric metering pump and the s4 ecu doesn't store error code data.

 

so what your saying is i cannot pull codes off of my ecu with the test lights?

 

It's a S5.
What do you mean by "limp mode"? Is that pretty much what i described?

Btw, there is no "stock pop-off valve" on a t2, there is none!

The third question I don't understand quite, but we didn't do anything with the cats, we just removed the air-pump, and welded shut the hole that was left behind at the exhaust pipe.

So the Oil metering pump could pretty much be the cause of my problem, is that it?

sincerely

 

It was the Metering Oil Pump.

Case closed.