Synful

Let me start by saying I have done extensive searching before asking this question. I have had another camaro (88 Iroc-Z) with a similar issue with a more simple solution. I am very familiar with code 33 and what relays and sensors it involves. That out of the way, let me get to the issue at hand.

Car: 1987 Iroc-Z 305tpi 700r4
Status: New MSD spark plug wires. I have not changed the spark plugs or cap or rotor or even done an oil change since I purchased it a few months ago. I want to get to those items, as I feel they are important, however, I wish to fix the major issues first and foremost.

Problem #1 (the MAIN problem)
ECM sets code 33 for high voltage at mass air flow sensor. This problem does not happen everytime I drive the car. I even had a period of two weeks where the car ran flawlessly. However, I now frequently recieve code 33 again and extremely poor driveability (surprisingly though it rarely stalls). The code is not thrown even in a predictable manner when driving (I.E. it does not happen at the same point during the trip). Although the problem does happen within 0 to 15 minutes of DRIVING the car (never thrown the code at idle as of yet). Hitting bumps and such does not appear to throw the code, nor does taking hard turns or anything else which would indicate a loose wire somewhere (very odd considering thats what I believe it to be).

Things I have tried:
Brand new remanufactured ECM 165 for MAF system.
Brand new Bosch MAF sensors (last of 3 which I have purchased for my 88 Iroc-Z. It performs flawlessly in its own regard)
Brand new connectors for the MAF sensor, and all 3 relays (also brand new) along the driver's side firewall
Brand new TPS sensor
Brand new IAC motor
I have tested for continuity between the sensor and the ecm with no bad results. I have also checked the grounds for the ecm which are good and retightened the engine grounds to the backside of the engine to make sure they are secure.

I have found a flowchart provided by the Trickster from tgo for code 33. I have also found a cover page looking sheet that describes what is happening when code 33 is set. They were helpful with my 88 car's problem, but unfortunately, this time around it indicates an intermittent problem right from the beginning, so I cannot reap it's benefits as I had previously. Here are the sheets for your reference:

http://www.infernusgaming.net/images/code_33_1.gif
http://www.infernusgaming.net/images/code_33_2.gif

If Trickster or anyone else has similar pages from a REAL chiltons manual that might assist me with specifically an intermittent problem or more detail on how the entire system works, it would be much appreciated.

I am at my whits end trying to figure out what this thing's problem is. My bet is something is loose somewhere. I have not truly the time or the real know how on how I should even begin to approach this problem any further than I already have. I am half tempted to switch to the 90+ MAP system, but I hear that is a bit involved as well (not that it is outside of my personal abilities, but I would rather be able to fix a problem rightly so than to run away from it).

What should my next steps be? Do I rewire the entire engine? How much does that cost? Should I have it professionally done? If so ABOUT how much would that cost?

This is just a car and it CAN be fixed. I will let no car outsmart me and force me to have ill feelings over my otherwise favorite model and year of car.

Please, any assistance or suggestions you can give will be graciously accepted and applied to my problem. If it does not remedy the problem I assure you I won't be mad for trying. All suggestions are open, as well as further questions regarding the problem at hand.

Problem #2 (smoke on startup - medium amount)
When the car sits it apparently builds up fuel in the cylinders, for when I start it up it plumes smoke enough to float into the driver's side window on a breezey enough day with the wind in the right direction. It smells like gasoline for what I can tell. I am full aware that leaky seals are a common problem in these cars, but I believe what I am smelling is fuel and not oil. Where should I begin to solve this issue or figure out what is going on further.

The same applies here as did above in regards to assistance.


Again, I thank those that take the time to read this, you all are a great group of people and I am positive that we might come to a solution or at least a conclusion as to what needs to get done.

Synful

could other items on the car cause a code 33 or is it solely dependent on what the two images i posted dictate?

for example. could crappy injectors, bad plugs, bad overall fuel delivery, etc. cause a code 33 to emerge indirectly?

rgarcia63

Intermittent connections can also be caused by temperaure expansion/contraction and are very difficult to pin down.

I assume you didn't replace the harness male/female pins when you replaced the connectors - did you test the male/female connector pins with the proper pin gauge?


Painless harness with emmissions about $400+SH

Is the smoke grayish? (I doubt that it's black.)
If you suspect leaking injectors, pull the injector fuses then run engine until it dies and quickly release the fuel pressure before you put it to bed.
It shouldn't smoke on startup, if it does you may have a faulty CTS sensor.

Synful

the relays and connectors are entirely brand new. anytime I buy a new connector i buy it with pins and wires attached and sauder / crimp them and heatshrink. all connections are solid and clean at those points. who wants to buy an expensive MAF sensor or some relays brand new and then go and connect it to a dirty ole connector :/

i would describe the smoke as white-ish in color. how can i most easily and safely relieve the fuel pressure? I would rather not use the schrader valve and spray gasoline all over my engine. when I go to start it up after letting it sit like this will i need to let the fuel pump prime for a little bit longer? And at the same time would I need to start the vehicle as quickly as possible so no fuel leaks if that is indeed the problem?

what is a CTS sensor?

rgarcia63

Put rags around and under the fuel rail to absorb the fuel when you release the pressure, you don't need to drain it just release the pressure.
It may have an initial 2-3 times longer crank time, but it should startup.
I don't think the injectors will leak enough in that time to cause it to smoke, if that's the problem.

CTS is Coolant Temperature Sensor for the ECM located in the frontal area of the intake, ECM doesn't use the instrument gauge temp sender to determine coolant temperature.

The reason I asked you to describe the smoke color is because fuel in small amounts and coolant smoke can be confusing.
White = coolant
gray = fuel
blue = oil

fire350tpi

But white could also be Condensation, After the rain myn do's it till the car is almost operating temperture

rgarcia63

If that going to be a problem in determining the color, don't do this test when the humidity is high.
The moisture in the air, or coolant leak has to condensate into water when it hits the cool air at the end of the exhaust pipe and drops out, the anti-freeze will retain it's color if that's what you're using as a coolant.