98NYFINESTVETTE

I received a code 34 awhile ago, I replaced the Relays. The car ran fine for a day. Then a code 33 came up. I replaced the MAF today, Still have a code 33. I then replaced the ECM. I disconnected the ground cable from the battery each time I installed a new part. I think I have replaced everything that I can. I have looked in the HAYNES book and I see that there is nothing else to replace. I give up. The book also to look for vac. lines that maybe off or cracked. I don't see anything wrong. I am just pulling my hair out :confused:

Has anybody had this type of problem? I also did not mention, But I don't think it has anything to do with the code 33 - My dash lights are off. I have been told that this is a common problem and it is most likely the ground on the right side firewall. Strange how the dash lights have not worked for a month and they worked for an hour on Sat. :confused: I thought I would mention the dash lights since I may have two problems or the two problems are related. Please don't be shy, If you have an idea or suggestion please leave a post.

vader86

Try running a search, on the Code 33 & 34.

The dash light thing is very likely unrelated. If they are all going out, you should first remove the bezel piece on the dash (carefully) and you will see 4 silver tabs. Twist and remove them, there is a bulb under each. The part is Sylvania 882. Be careful not to touch the new bulbs as finger oils cause them to burn out quickly.

If that doesnt fix it permanently, you will have to remove and disassemble the dash unit to resolder the connections inside.

It is sometimes a loose wire in the engine bay, but usually its one of those two.

98NYFINESTVETTE

Hello, I neglected to write in the last post that the dash lights are out. The signal lights and high beam indicator are on. I was told that this maybe the ground wire on the firewall below the right cyl. head. I was not sure if the two problems are related. :confused:

98NYFINESTVETTE

How would I run a search on this problem? Thanks

hz900

Your dash prob. is inside the cluster. If you are good with electronics you can fix it yourself. one of the pins connecting the two circuit boards together has broken loose and needs to be resoldered, and you might as well redo all the pins while you are in there. This is a known prob. and all the early C4's with digidash will eventually have this problem. The problem is a design flaw that didn't show up until after they went to the new dash is what I was told.

vettmech

Yes the dash can easily be resoldered .....use a BIG soldering iron or a powerful gun ........ when I did mine I used a big iron and touched the sloder joints and they turned shiny so I knew the took. If they are dull it's from what is called a cold solder joint. On one I had to touch the joint with some solder but the others were fine. There is a very good article on repairing these here someplace written by BATTEE (I think that's the screen name) follow it and you'll be fine
:seeya

Steel Blue 91

Try this link:
http://forums.corvetteforum.com/zerothread?id=390639

Might help.

VetBoy89

I had the same problem, mine was consistent, everyday I was haunted by this annoying 33. After fighting it for a few months I finally noticed that my TPS would only read 3.65v at WOT (.54v closed). At first I didn't think this was related to my 33 but after some advice here on the forum I decided to go ahead and replace it. Guess what, I haven't seen a 33 since. :) Coincidence? I don't think so, but then again, maybe I just jinxed myself :D

vader86

Use the "Search" feature, upper RH corner of this page

search in C4 Tech, both recent and archived topics for the Code 33 and 34 problems

jmr302

For in depth help with the digital dash check out this guy's page: www.batee.com

Blue88

I had the same code 33 problem you are having. I replaced the MAF, relays, checked the wiring, adjusted everything and still got the code. I finally repaced the oil sending unit (which shares power to the MAF) and this fixed the problem for 1 day then it came back. So I pulled the fuse to clear the code then drove it until the light came back on. Pulled over and turned the car off for 1 minute and restarted and drove the car till the service engine light came back on again. I did this 3 times and the light never came back on again with code 33. One thing I would suggest though is to pull the wire harness connectors to the ECM off and plug them back in a couple of times. Doing this cleared a code 36 I kept getting after going through every suggestion in the service manual. The very last tip was to check the connections at the ECM if all else fails. The same suggestion goes for fixing code 33 problems if all else fails.

98NYFINESTVETTE

Funny that you mention the TPS. The car is acting as if the TPS is not working properly. I have this same problem with other vehicles that I have owned, So I know how they act when they are not working properly. I think that the TPS will be the next exspence. The car is acting as if it is bad. The idle is rough and when you lift off the gas the RPMs drop very quick with a slight surge and then into a rough idle. Funny I was thinking that today when I was driving it. I also noticed the gas mileage has been worse. I figure I would replace the ECM sooner or later since it is old. I would like to thank everyone for the help, This is has been very stressfull since I do race the car at a local track in a points series (Corvette Challenge) in New Jersey. This problem has been around awhile has cost me some races. The car was so consistant in the 1/4 mile. Then it would decide to do what ever it felt like doing.

98NYFINESTVETTE

I will remove the cluster to check all the connections. I will solder anything that looks dull and not shiny. I will also inspect the firewall where I was told that the ground strap/wire for the cluster is located. I was told it is below the right cylinder head on the firewall. Thank you for the advise and tip. I will leave an update after I have removed and reinstalled the cluster. I am crossing my fingers that all my troubles will go away this weekend after I work on it. Before all the problems came on, I was having so much fun driving it. I have had the Vette for 10 months and it has been on the road for about 6 months. I mainly drive the car to the track and one day a month to work. I don't work in a nice area. Again thanks so much for the help :D

98NYFINESTVETTE

Thanks for the link, I will check it out. Maybe I will stop pulling my hair out now. :D

98NYFINESTVETTE

This link was very helpfull, Thanks a lot. :D

98NYFINESTVETTE

OK, He is an update. I replaced the TPS. The idle has improved a little. I still have a code 33. Even after disconnecting the battery. So far I have replaced the TPS, ECM, MAF and the relays. I did adjust the TPS to .69 volts. If I go any higher in the voltage, The idle will increasde to 1,700rpms. I have found that .69 volts I do not have much of a surge and the rpms don't drop that quickly when I release the accelerator. I still am stumped to why I still have the code 33, I do feel that there is something still wrong. The Vette accelerates like an animal. If anybody has any other ideas or suggestions PLEASE HELP.

98NYFINESTVETTE

I also have been cleaning the throttle body, This has made a difference. Even though it looked clean when I looked inside. I will keep playing till I get it right.

Aggravated4life

Just a question...has your TB screw ever been turned out more?To try and increase the idle or anything?Is the cover cap still there on the back of the TB screw or is it gone?
Let me know...because what happens is like the TPS signal,if the minimum air speed screw has been tampered with,it can increase the chances of code 33 coming on in conjuction with the TPS position.
Code 33 is also an unrealstic airflow into the motor.This is a common code to get when installing a larger TB onto a TPI with a MAF and not adjusting it right.They dont always run right out of the box and same symptoms happens when the idle scew tampered with.

Also,if this code is new and started after you replaced a MAF,check the wire harness and the pins on the sensor.I believe its the green wire on the harness that signals the ecm for the code 33.If you have a TPI manual and a voltmeter,you may be able to use it and see if you have a voltage drop between the MAF and the ecm itself along the wire.
One more thing,,,if your car has a somewhat bad idle,pull off the PCV valve while the car is running and let me know if it idles a little better.Just pull it off for a few seconds or so.

Just throwing ideas.
Good Luck!!
:)

86VetteBill

Boy oh Boy - that infamous Code 33 :smash: I had the same problem and I temporarily fixed it until I can get some 'under the hood time' on MY car instead of Dad's S-10.... :rolleyes:

I checked out the MAF relay and burn-off relay, but refused to replace parts that might be good. Someone, in a previous post mentioned the little green wire that goes to the MAF. It can cause problems. I played with mine for a few weeks.

This might be stupid, but check this out: you know the wires that go to the MAF connector that are inside the plastic tubing under the flexible 'MAF to TB' tubing? Well, the plastic tubing was bent so that it was on the passenger side of the 'MAF to TB' tube. I pushed it under this tube so it sticks out of the driver's side of the 'MAF to TB' tube.

I haven't had a 33 since I did this - about 3 or 4 months ago (daily driver). :D I'm picturing that there's a short in that little green wire to my MAF. This must have taken care of the short in that green wire? :confused: I'll check mine out more thoroughly soon.

I hope your '33' is as easy as this mine.
:seeya

98NYFINESTVETTE

I just checked the wires going to the MAF. The green wire has 5.04 volts before the plug. On the side of the plug where it makes contact with the MAF sensor, I have 5.04 volts. I made the final adjustment to the TPS. That is set to factory specs. I still have the code 33 coming up and I still have that quick drop in RPM's when I release the accelarator - As if it was going to stall. The engine does not stall, Just a little sloppy after coming down from decelarating more a moment. It is obvious that there is something wrong. When you first start the engine it idles low and a little rough - then the idle will be normal. I think I have read every post in regards to a code 33. If anybody has an idea please post it. I erase the codes often, But they come back as soon as I start the engine.