ok heres the deal. Its not my vette, its my step brothers. I have spent some time under the hood etc helping him with it etc. Recently the check engine light came on. Instead of letting me take a look at it, he brought it to a mechanic. The mechanic replaced the fuel pump, messed up the gas guage. then said "Opps, guess that didnt fix it. I have no ideal why the check engine light is on. Heres your bill..

Well first I told him "Please, let me take a look at it before you ever bring it to a mechanic."

He said "I didnt think you could fix the check engine light"

me "ok, <plugs into aldl, checks the check engine light i get the 12 12 12 followed by 33 33 33, and 34 34 34 12 12 12 ...
I tell him, hmm engine code 33 and 34, since you didnt get the helms manual I told you to. let me check it out on google.

Looks like its a MAFS issue. I have not looked at it to determine what part of the MAFS is having issues (hardware / wire/ loose connection etc). I was going to take a look at it this weekend.

Hes been driving it a little here and there, so I call him today to see if he wants to look at it on saturday or sunday. He tells me that he brought the car back to the mechanic that originally looked at it, becuase he was on the highway and couldnt get over 40mph and the tranny felt like it was slipping.

When he told me this, it peaked my curiosity. here are my questions...


Is it possible that the MAFS problem was causing the car to improperly adjust to the amount of air it was getting at 40, which limited it from going faster, and the tranny was "slipping" (acting weird in my eyes) because the ECU didnt know how to handle the bad data from the mafs?


(he had the tranny rebuilt/replaced like 1000 miles ago becuase of the same problem.)


Please help me, my step brother is about to trade his 86 c4 for a mid 80's camero or iroc. I keep telling him, its a 20 year old car, you bought a project car, its gonna need some TLC. if you buy a 20 year camero, or a 20 year old iroc its gonna need some TLC too.

I would just hate to see him trade his vette for an iroc. Our vettes look so nice parked next to one another at the family gatherings.

Sorry for the rant. I guess im just sad that hes bringing his car to the mechanic before letting me look at it.

Although the mechanic broke his fuel guage, replaced a good fuel pump.

and I have fixed his cooling fan, 1 of his headlights, he saw me fix my vette when I bought it it wouldnt even start. Ive had mine in tons of peices.

Yes, I know there are some differences between the 84 and the 86 (top 1/3 of the engine or so.) his has a hatch release button on the doors, the cluster is a little differnt..

But if the mechanic cant even pull the engine codes of the ODBI interface and pull a code 33 and 34. why bring your car back to him ??

 

If the car was in limp home mode, which would trigger in the case of MAF problems, it might end up with the same symptoms, yes.

 

http://members.shaw.ca/corvette86/Code%2033.pdf
http://members.shaw.ca/corvette86/Code%2034.pdf

 

Check the air intake tube as well. If it's got a crack or a hole in it, (usually on the underside) that will throw a MAF code too.......This is especially prevelant if you use one of those aftermarket "smoothies" type.

 

Simply knowing where the codes originated is just a start. It isn't easy to trouble shoot codes with out a trouble shooting chart, without wasting parts, unless you are VERY familiar with the workings of the systems. Your description of your step brother doesn't sound as though he is. INSIST that he buy a FSM.



No. The ECM has nothing to do with the operation of the 700R4/4L60 transmission.



My '84 has hatch release buttons in the doors.

RACE ON!!!

 

what's that saying? you can lead a horse to water...but you can't make it drink. FSMs are a must...and the so called "mechanic", well,can't even pull the codes???? codes 33,34 and 36 can be frustrating but the FSM trouble shooting chart helps make it much easier. If he doesn't want to invest a $100. on them...well, maybe he should bail.

 

Once he buys an unneeded MAF, he will have more than paid for the FSM, without having the benefit of being able to read it. Remember, "Don't shoot the messenger".

RACE ON!!!

 

Just had a friend with the same codes, replaced both relays and no more problems $23.00 repair cost

 

Follow post #3 for now until you order your FSM.

 

which relays were replaced/location? I have codes 33-maf and 43-knock and car doesn't accelerate right..I've posted a thread and got many responces and JUST bought a FSM manual a few minutes ago from helms after 3 years of debating on buying one--in the meantime I'd like to look at my relays--

 

thought you posted 33 and 34? if you're asking about the relays for those codes and where they are...two, side by side behind the battery.

If you are now asking about code 43..that's the knock sensor..located in the block..passenger side...87 has a single white wire.

 

ohhh ok, I know which wire your referring to, its located just under the passenger header and is a white wire on a plug going into the block---To let anyone know just before these 2 codes happened on mine, I had to take my car to the engine shop that originally did all my work--because the pcv slipped out of the valve cover and oil was spraying everywhere and its all over some wires INCLUDING that white knock wire....I haven't gotten to examine everything. The original post I made was for codes 33 and 43--but they happened at the same time and my accerlation seemed to get worse!! hopefully this oil spill mess can further enlighten a possible problem I can fix and solve the codes. I'm hoping its not a grx issue, I don't see how I search every gx wire--Not sure if I can even jack the car up due to the greenwood body parts on the car (make it almost impossible for ANY hydraulic jack to lift car) almost would have to drive car on a steady incline inorder to get under it--but what a job!! Maybe if hot oil has gotten on the knock wire and causing this whole thing?
PS...the reason the pcv slipped out is because I have braided hoses which aren't shaped like the factory hoses to prevent flexing--so they do have abit more pressure causing it to bend away from the pcv in the valve cover, but the shop installed a MORE tighter grommet to prevent this from ever happening again---but like I've said before the car ran perfect before the pcv slipped out sprayed oil, and I've examined the intake hose at the maf and intake and NO cracks