dwillms

Hello,

I just finished washing down my engine bay, and after letting it dry off for a while, I got a code 33 after starting it up. Checked my IAC(more on that later), and my TPS voltage which was fine. Car seems to run alright, maybe a little rougher but not enough that you could notice much of a difference if you didn't know.

Before I go searching for a new MAF sensor, what relays/wiring could I check to see that might be fried, and how would I go about checking them? Also, would it be possible I knocked a vacuum line loose perhaps? Any sort of procedure with diagrams would be excellent. I let my car sit overnight and dry, disconnected battery in the morning and let codes reset, but still get code 33.

About the IAC: No matter how far in or out I set the IAC Torx bolt, when I try to adjust the idle, the car will stall immediately when I start it with the IAC unplugged. Is this a bad IAC motor possibly? It has always been like this, not just since I washed the engine. My car has always idled about 1000 in Park when I start it up, after getting warm it gets down to 600 or so in drive. Seems to search for an idle a little bit too when it starts cold.

Thanks again,
-Dustin

Trickster

UUUMMMMM!!!!!!!!!

There is no torx screw or bolt on the IAC. You are probably talking about the idle speed adjustment screw in the throttle body at the throttle lever. Also if you are trying to adjust the idle by just turning that screw, that is not the proper procedure for doing it. Search the tech articles on this board and you will find the procedures for adjusting the TPI idle.

dwillms

Yes, sorry my bad I did mean the idle speed adjustment screw. I have read the procedure and done this correctly twice already, with no results.

Here is an update on my problem: I checked out the MAF and it's connections, looked fine. Fiddled with the relays, and here is what happened. The car would start, then nearly stall, then idle and run somewhat normally. After switching relays back and forth, I found out that when I switched the burn-off relay with the fuel pump relay, no more near-stalls and no more "check engine" light. Since switching MAF power relay and fuel pump relay would still cause a problem, now I know that the fuel pump relay is the one that is bad(or so I think at least).

Although, this still leaves me with one more question: If the fuel pump relay went bad, why would I get a code 33(high MAF voltage), and not a code 54(defective fuel pump relay)? Also, why when I unplug the burn-off or MAF power relays would I also not get any trouble codes? Thanks again,

-Dustin

Trickster

One, the code 54 = Fuel Pump Circuit (low voltage), that is why you didn't get it. Here are a some troubleshooting charts for codes 33 and 36 for you to look at.

Trickster

page 2

Trickster

Code 36 chart

Trickster

page 2

dwillms

Thanks for the info. Haven't had a chance to go through those charts yet, but here is what's happening.

After switching burn-off to fuel pump relay, car started nice and idled fine. Shut the car off, started it again. After idling for about 30 seconds, the car dropped to about 400 RPM and just about stalled, sputtered, and returned to crappy idling and "check engine" light. So problem isn't solved after all

Now, I have got the car to do this one more time, start fine and after 10 seconds just about stall and SES light. All I seem to be getting is code 33 whenever I check my codes. I have tried starting the car with all 3 relays disconnected, and the same symptoms persist. If the fuel pump relay is disconnected, how can the car start and run?

Thanks again for the great info, right now I basically don't know whether to check the connections(seem to look alright) or try new relays, since I don't know if any of the 3 are good. Is there any way I could check voltages with a VOM on the relays to see if I am getting the right voltage there?

-Dustin

-Dustin

Trickster

Your oil pressure switch/sending unit will operate the fuel pump as a back-up to the fuel pump relay once 4 psi of oil pressure is built up. You can check the conections with a test light or multimeter to determine if there is any voltage going through the connectors. Just follow the chart. BTW, why did you wash out the engine bay.

dwillms

There was about 10 years of gunk and crud built up from previous owners not caring for the maintenance. I have a couple of questions about your flowchart:

1) How would I go about jumpering ALDL terminal "G" to 12 volts, what would I connect the fused jumper to?

2)When probing terminal "E", do I only probe it with the test light ground, or what do I connect the test light to?

Sorry I'm not much for electrical yet, I'm still very green when it comes to this kind of stuff. Thanks a bunch,

-Dustin

Trickster

I use a 14.4 volt battery from a cordless drill and a wire harness I made using some terminals from an old connector. I stick the positive wire into pin "G" and the negative to pin "A". Beats lugging a 12 volt car battery around and it works very well. 2. when probing terminal "E", if you have a test light there should be and alligator clip on one end and that should be connected to a ground. The needle end is the positive end. Don't worry Dustin, the only dumb question is the one you don't ask.

dwillms

Yes, we all feel like idiots one time or another Like I said, not much experience with electrical and this sort of thing so far. But you have to learn somehow. Took a look, couldn't find the test light in our shop today, so I will go through that chart tomorrow to see what might be the problem. BTW, where did those pics you posted come from? I have a Haynes repair manual, it has some good info, but I wish stuff like that was inside of it as well.

Thanks again,

-Dustin

Trickster

Don't we though! The information I am posting here is from my GM service manual.

dwillms

How much could you pick one of those up for? I found a guy who had an 85 Camaro shop manual. Would shop manual be like an asssembly manual, and service manual be repair? Thanks,

-Dustin

Trickster

What I have is a GM shop service manual like they have at the dealerships. I got mine through the local dealership. You can order them through Helms at the site listed below. Your manual would run about $76.00 (US), you might be able to get it cheaper through the service manager at the dealership. They have yours in stock at the moment.

http://www.helminc.com/helm/Result.a...KQJ7JSSSHQ6HKA

dwillms

Ok, got a test light and went through the flowchart. Here is what I got:

Jumpered ALDL terminal "G" to 12 volts. First time I did it, I could hear something(fuel pump I believe) coming on, but didn't get a good ground to use test light. Second and subsequent times, couldn't hear fuel pump, but test light came on.

Probed MAF harness terminals "A" and "B", both times light on.

I wasn't sure if terminal "D" should be checked with engine running or not. Checked both, VOM read about 0.06-0.07 volts both times. I took this to mean that it was "OK".

Terminal "C" read just over 5 volts when checked.

This leads to "faulty MAF sensor". Exactly what I didn't want to see. Now, after reading through everything I have gone through, would you come to the same conclusion? I have a hard time believing that I could have fried my MAF just by washing down my engine bay. While this could be the case, to me it seems unlikely but I could be wrong.

What doesn't make sense is that I know for a fact when I changed my MAF power relay with my fuel pump relay, I started and ran the car fine for a little bit before I got a code 33(just as I stated before). I have heard, but am not sure, that when relays go bad they can work sometimes and then cut out other times, instead of just quitting all at once. I'm hoping to pick up a couple of new relays just to make sure this isn't the prob before I have to spring for a MAF.

Any other advice or areas to point me towards? Right now I'm feeling a combination of and Thanks again,

-Dustin

Trickster

It doesn't neccessarily mean that you have a bad MAF sensor. You did not indicate if you checked terminal "E" of the MAF harness. Also, it says to check all associated connectors and wiring. Go back and check terminal "E" if you haven't already done it.

dwillms

Ok, went back at it tonight :lala: Decided to hook everything back up and start it up again. I blew out the MAF harness and all 3 relays with the air compressor, put dielectric grease on all 3 relays and harnesses. Reconnected MAF, hooked back up all air intake ductwork (which I hope to get rid of ASAP). Fired it up and let it idle for about two or three minutes in my shop.

No code 33 showed up during the brief testing session. Car started nice and easy, idled straight to around 800-900 RPM. Seems to be running a little rough, but it's also sat in my shop for basically three days. Also seems to be running a bit rich, but I'm definitely no expert in this matter. Since it's 11 PM at night and I have to be up at 6 AM for work, I threw the battery charger on overnight and I think I will take it for a test drive tomorrow to see how she runs.

I'll let you know if anything else falls apart on me. Thanks for being a super help so far.

-Dusty