Help with injectors...

[1988GTU]

Cool beans!

[ForcedFirebird]

I know I need to add a 1/4 turn valve lash, that is why I am running slighty rich.
Here is a little more added info...
"33- manifold absolute pressure (map sensor signal voltage high
33- mass air flow (maf) sensor or circuit - excessive airflow indicated "
"Check the vacuum hoses from the MAP sensor. Check the electrical connections at the ECM. Replace the MAP sensor"
"Trouble Code 33 indicates that the Mass Air Flow (MAF) sensor is reporting more air is entering the engine than makes sense based on RPM and TPS. The MAF sensor produces a frequency output. The frequency varies proportionally to airflow. The ECM monitors the frequency and thus determines airflow into the engine.

The conditions for setting this code are:

* no Code 21 or 22 (TPS Error) present, and
* the air flow reported is > 40 grams per second, and
* TPS indicates < 10% throttle position, and
* the engine speed is 1400 RPM or less, and
* the above conditions exist for over 5 seconds.


Typical causes for this code include:

1) Faulty MAF-to-ECM connection
2) Exceedingly noisy spark plug wires
3) Poor routing of MAF harness (i.e. near coil packs)
4) Maladjusted TPS sensor
5) Defective MAF sensor
6) Defective ECM"

Now what may be happening is that your car might be stuck in open loop by default since that sensor has failed. You have tried changing the sensor?


Hope that helps!

Thanx again! I got home early from work today and had some light to work by (1 4' florescent in the garage isn't enough) and discovered that I hooked up the A/C vac line instead of the MAP (dumbazz), VIOLA! The car is running beautiful!
As far as the PROM is concerned, a bud is going to burn a chip for me and I discovered it's less than $100 for me to get started burning for myself (not including the chip I have to pay for from him - <$40shipped).
.
I can't thank you enough sappy and 88gtu for your input!
Hopefully I'll return the favor .

[ForcedFirebird]

Why couldn't you use a RRFPR?

That's the Paxton FMU I have is for.
Or are you suggesting something different?
.
Well I've got the car running good, except the low vac problem still exists.
Here's what's happening...
Reset ECM, start, let idle
idle maintained 2-5 seconds
idle jumps to 1500 or higher for 2-5 seconds
check engine light blinks, then stays on
idle goes to normal.
Reset ECM, keeping off idle runs fine (and no light).
.
I'm guessing this is in limp mode now?!
.
Sappy, I know you are right about the order of things, the EMS will be bought soon - guess I'm just looking for a "band-aid" for the moment. Might put the stock injectors back on for now and just stay with low boost untill I get my hands on a new system.

[1988GTU]

Why couldn't you use a RRFPR?

[ForcedFirebird]

The AFPR works to set your range but if you turn it down to make it run right...you are really just using the same stock size injectors in the end with worse atomization

Hoping in conjunction with the 8:1 FMU to increase the pressure under boost.
Yes the atomization is going to be worse at idle, but under boost would be corrected.

The O2 sensor is a switching type, which means the voltage go above .5 volts, then below, and repeat.

One of my next purchases is a wideband o2, I want it for the aftermarket EMS anyways, but I found documentation of measuring voltage at the o2 sensor for AFR. Here's a link: http://www.thirdgen.org/o2tuning A Fluke meter will tell you average.

[SappySE107]

You aren't going to get anywhere with that setup. The AFPR works to set your range but if you turn it down to make it run right...you are really just using the same stock size injectors in the end with worse atomization. Bad way to go about it. The O2 sensor is a switching type, which means the voltage go above .5 volts, then below, and repeat. The ECM averages those to come up with the assumed AFR per voltage. A voltmeter won't really do you much good. You need to run stock injectors until you get your turbo on there, or better yet, get the programmable setup on there now and leran how to tune it how it sits before you add the turbo.

[ForcedFirebird]

Did you try that with an AFPR? I've got the car to idle/run after removing the spring in the stock FPR and relying on the aftermarket AFPR tapped into the fuel return line. My problem now is getting rid of the code33 (which I believe is causing "limp mode"). I thought I had a multi-meter that was capable of measuing low voltage (not quite), so I'm going to have to borrow my employee's Fluke to see what's going on with the Air Fuel Ratio (relying on the innacurate stock o2). Just to confirm, the AFR is optimal at 14.7 (I'm <13' above sea level)?

[SappySE107]

Probably. Unless your coolant temp is never getting warm and you aren't driving more than 3 minutes. I only know what happens in the FWD OBD1 setups but you won't leave it in open loop unless the O2 never moves, the coolant temp is always real cold, and you don't drive it long. It will go into closed loop with a bad O2 though I dunno if it will go to defaults/limp home with a constant O2 voltage.

You certainly can't run 24# (more on a GM) with the stock tuning. I tried the 19# ford injectors (21#) with stock tuning on my 3.1 grand prix with porting and cam and other stuff. It was way off.

[ForcedFirebird]

No way to scan, plan on using an aftermarket EMS but untill then would like to see the turbo up and running using mechanical tuning procedures. I'm not intentionally keeping it in open loop, but everything I read tells me that I'm staying in open. Is this information incorrect?

[SappySE107]

How are you keeping it in open loop again? Do you have any way of scanning the computer?

[ForcedFirebird]

Thanks for the input, maybe I'll start a thread on that?!

[1988GTU]

That I do not know.

[ForcedFirebird]

Nope, I'm running in open because of the smog delete.
My car is MAP equipped, not MAF.
The only time the code is being thrown is during idle. Once I get the kids to bed(all four), I'll go check the o2 voltage and see. (can't wait to get a 3 wire o2, lol)
As far as valve lash, I'm old school and set the cyl to zero lift and do the "wiggle test", perhaps that's not accurate enough for the fuel injection systems (first attempt to mod a FI vehicle, all the others were carbs).
.
Do you know what kind of effect the 33 code will have on driving/performance?

I'm such a dummy! I was going online to check the voltage I need to be reading at the o2 sensor. Since I'm running in open loop this isn't going to help because the ECM is reading temp/MAP only anyways.
. Without re-programming the PROM, is there a way to sent the ECM into closed loop? (perhaps shorting/resisting the wires for the smog pump?)

[1988GTU]

I am not sure. I could guess bog or hesitant accel.

[ForcedFirebird]

Nope, I'm running in open because of the smog delete.
My car is MAP equipped, not MAF.
The only time the code is being thrown is during idle. Once I get the kids to bed(all four), I'll go check the o2 voltage and see. (can't wait to get a 3 wire o2, lol)
As far as valve lash, I'm old school and set the cyl to zero lift and do the "wiggle test", perhaps that's not accurate enough for the fuel injection systems (first attempt to mod a FI vehicle, all the others were carbs).
.
Do you know what kind of effect the 33 code will have on driving/performance?