When engine is cold it runs ok, after about 2 minutes its starting to stumble and it will die if im not giving throttle. If im giving throttle it runs really bad.

Win-aldl gives me error code 41 Cylinder Select Error.

When im looking at dash in winaldl when i just turn on ignition, it gives MAF 23.0, TPS 0,2 % and O2 0.451.

shouldnt MAF and O2 be 0,0 when its not running?

half year ago i changed temp sensors and rotor, cover, cables and sparkplugs.

The only modified on this engine is deleted AIR, headers, deleted cat and a hypertech chip in the box. I checked what the chip does so it should just keep the engine cooler. i think

 

Have you tried unplugging the MAF?

 

You mean when the engine is not running?
Havent tried that.
I tried to have it unplugged when idling engine, but it just stumbled and it was no difference.

 

That is NOT right at all! My new borg warner MAF showed 3.0 grams/sec in WinALDL with key on, engine OFF. Also, your TPS seems to be way off. Ideal range is 0.54v, but you can get it "in the ballpark" of this number by a few 0.01v's and still have everything run OK.

 

Thank you very much, seems like i have to change the MAF.

I forgot to say that the tps shows in % not in volts ( dash in win-aldl )

 

0.2% sounds like It's calibrated right on the money

 

I have also checked the resistance in the injectors and that seems to be ok too. 16.0 and some was 16.1

Is it possible to check if the MAF is broken?

 

The O2 should read .451V with engine off and key on.

Try unplugging the MAF with engine running, to see if it improves.

I wouldn't judge the MAF until the filament warms up. I know it meters the air flow through resistance changes across the filament.. I wonder if ambient temp effects it.

I am just spit-balling here but, you could hook up a fan to pull air across the MAF at a constant rate (through a tube of some sort) and monitor the voltage to look for spikes (indicating erroneous readings). Obviously the engine would be turned off and the air intake would be taken apart.

I would like to learn of an actual test for the MAF.

Hope this helps.

 

Now i have tried to unplug the maf and its the same problem. I havent unplugged when the engine is running. but i have unplugged and started and now it felt like it doesent use the open loop. it runs like crap directly when i start it.

When i had the ignition on and engine off, maybe for 8 min. somekind of relay or something started to have weird noise, it went on and off rapidly and irregular. like fast and slowly on and off. And just on its own, i didnt do anything that started it. I think the noise came from between the runners somewhere, i couldnt locate it. Does someone know what it is?

 

I read up on code 41 and attached what I could. You mentioned something about an autotech chip...seems that your memcal may be wrong or not seated properly.

Hope this helps.

 

Thank you.

I will check that.

 

I have never seen a bad memcal, but the only time I ran across this the ecm turned out to be bad. you might want to double check the code with jumpering a to b on the aldl. If there is a code 41 your ecm will be in limp home mode and run bad. Is the autotech a piggyback chip that maybe installed incorrectly ?

 

Its worth a try, i did it a couple of months ago and i had the 41 then too. But i also had some another code too and now i dont remember anymore what that was. I think its a "piggyback" but its pretty hard to install wrong.

 

If there is a issue with the piggy back chip , or zif this will cause it to throw a code 41. you might want to remove the aftermarket chip all together and disconnect the battery and see how it runs after you do that reset.

 

Problem is that i only have the aftermarket chip, i bought the car this way.
and the limp home mode doesnt take me home im pretty shure its impossible to drive the car now. it just dies.

 

I would be looking for a used memcal 86-87 have no vats 88 some have vats and the best is the 89 you would need a vats bypass module or have the vats programed out of the eprom but you could eliminate the ninth injector. The memcals are referenced bye broadcast code letters on the eprom they can be identified on chevythunder.com

 

I am looking, but there isnt much of the f-bodies around here. i forgot to say what car i have, its a -87 GTA so i have no VATS. But if i find a memcal with vats. where do i find a vats bypass module?

 

http://www.painlesswiring.com/webcat...rchField=64023

http://www.ebay.com/itm/GM-VATS-PASS...ht_3637wt_1055

 

Nice Thank you!

I was just in the garage and tested to unplug the chip and plug it in again. nothing happened. its a socket where i put the chip so thats impossible to connect wrong.

But shouldnt the car run atleast a bit when its cold maybe 5 degrees celsius. should be 41 °F

I cant even get it started without giving it throttle.

 

I would start with a ecm replacement and then be on the hunt for a memcal. Any of these service numbers will work.

1227165,16198259,16198445, 88999128 ,88999194

 

Thanks again!

 

Hope I was of some assistance let us know what you figure out !!


https://www.thirdgen.org/forums/engi...9-259-ecm.html

 

You know I wonder if some bone head installed a commodore/ holden chip in the ecm

http://www.autotechengineering.com.au/Our_Services.html

 

You mean in my ecm? OOPS! sorry i wrote i have a autotech chip but its a hypertech. its the number: 127062

 

oh !! I ment chip the older commodore holden ones were made by gm / acdelco / delphi electronics.

 

you know you might try a 1227808 ecm it has a slower baud rate but should work without repining just install your hypertech and see if it works. that ecm maybe easier for you to get.

 

I don't mean to hijack a thread, but I'm also having some very rough idle issues. Seems to run fine when I first start it, but after a minute or so when the idle comes down it starts running like crap and surging. No codes at all.

I also have the WinALDL cable, mine reads (key on, engine off)....
MAF 23.0
TPS 1.7% .61 volts
O2 .45

With engine running (I'm assuming limp home mode)
MAF 9.3
TPS 2.1%
O2 .43

Any ideas? I thought it was a faulty EGR, so I blocked it off, but no improvement. Replaced the ignition coil today too, but that didn't help either.

 

Well I got curious so I went out and unplugged my TPS with the engine running, the surging stopped immediately and it ran at a constant 800 rpm (it has never idled that smooth while I've owned it). Does this mean my tps is bad?

 

I would do a sweep on the tps with a ohm meter.

 

^____X2 what tunedperformance said.

.61V is a little high; it should be .54V at idle. Reset/adjust it and see what that does.

Hope this helps.

 

It's the top two wires on the TPS that are supposed to be tested right? I have a digital multimeter and when I set it on '2' and probe those two wires I'm only seeing .004 volts (with key on).

I may not even be doing it right. I'm not an expert with a multimeter.

 

Yes, it is the top two wires that are measured. The target voltage is .54V.

Don't know what setting 2 is..., but look for something that between 0 and 10 volts (normally DMM settings vary by multiples of 10). Pay close attention to where the decimal point is in the display and use your car battery as a standard (to become familiar with DMM).
For instance: to set my TPS, I set my DMM to "20V" to measure voltages (0-20V), the next available setting is "200V" (0-200V), and so on. If you are new to DMM's, just do a quick search (I think there are "facetube" videos that introduce DMM's).

Hope this helps.

 

I'll snap a pic of mine tonight when I get off work, but I think '2' is anything under 2 volts, the next higher setting is 20.

 

Here's the DMM I'm using.

 

EDIT: 80schild finally solved his problem with new injectors.


Hmm...the problem is the sweep of the TPS (.54-5.0V) so 2 will probably get maxed out and 20 won't be low enough. I suppose you will just have to use both settings.

So reset the minimum idle and then adjust the TPS to .54V.
Resetting the minimum idle:
jumper A & B on the ALDL
key on
wait 30 seconds
disconnect IAC
start engine
adjust idle to ~450-550rpms (check underhood emissions sticker)
key off
reconnect IAC
remove jumper A & B on ALDL
adjust TPS to .54V
drive and enjoy...

Hope this helps.

 

I agree use the 20v setting and make sure that button is set for dc. you can also unplug the tps and do a ohm sweep to check for bad spots on the tps.

 

A guy called me and said that he has a ECM for sale.
He said it has number: 16198262

Its from a -91 5.7 with VATS

Do you think its possible to use if i use a vats bypass?
Can it be some problems with MAP and MAF, when i use MAF and -91 is probably MAP?

 

Pajjen that is a map ecm not maf

 

Ok so its "impossible" to use MAP ECM on MAF system? impossible is not the right word but if i like plug & play

Thank you tunedperformance for all fast answers!

 

Pajjen...I have a spare ECM that I am selling in the classifieds (can't find the add). It is a 88' 1227165 ecm (MAF). I don't know anything about the baud rate (fast/slow or better/worse), but if you need one...

What does WinALDL show the O2 as when running (always low/high)? It should cycle between 1.0V and 0.1V.

Have you tried to reset the minimum idle yet?

Thoroughly clean the IAC housing/passages in the TB.

Check base timing, should be around 6 degrees.

Does the exhaust seem rich/lean when it runs?

Is there alot of carbon buildup inside the plenum?

Hope this helps.

 

Skibum2100, he is getting a code 51 we were thinking ecm or possible memcal. I can reprogram the 88 memcal you have to that of a 89 so the cold start can go away. This weather is awful today no way i'm driving into boulder , lol

 

Code 51, I thought 41? Reprogram memcal, what, mine? Then get rid of VATs too.

My commute was 2 hours today, gotta love the snow! I should have been headed to the ski lifts...

 

I thought he said 51 ? and yes get rid of vats on yours actually reprogram it with a $6e definition so there will be no cold start injector just different pulse of all eight on cold startup.

 

my bad yes 41 !!! although listed memcal can be ecm as well.

 

I run an '89 factory chip, my only spares are Hypertech and '88 factory. I didn't think either of these chips were reprogrammable, thought they had to be opened up and remove the chip, re-solder in a reprogrammable chip or socket. I would love it if you could hook up and reprogram the chip without opening the case.

Oh yeah, and we still need to help Pajjen, at some point...(quietly chuckles).

 

I uv erase them, soldering in a new one the heat usually destroys them. or a moates.net g1 adapter works well. oh we were helping him ??? jk pajjen we will help you out !!

 

I have seen a couple hypertech one they have a zif socket and they made the netress, I have seen them solder in a one time burn chip and uv erasable. The early years they purchased gm memcals and and uv erased them and installed there white covers. now they are all piggyback one time bun on zif boards.

 

.. Sounds like a temp or O2 sensor, but you said new temp. sensor...

.. The DMM doesn't go 2 - 20 volts, all scales start at 0 volts... (0 - 200MV, 0 - 600V, etc.) the smaller scales just increase the definition of the readouts for more precise breakdown... i.e., the 600V scale prolly doesn't read in tenths of a volt...

 

Which sensor did you replace, the one for the gauge or the one for the computer?

In WinALDL does the value for the engine temp ever change?

Hope this helps.


edit: From very first post: "I changed temp sensorS"...plural form of sensor...sorry, got my own answer.

 

Pajjen,

Did you get a chance to play with your car any more work this weekend?