So i was driving my 89 Formula 305 TBI the other day, when I went to get on the freeway i hit some snow and started to fishtail, not a big deal i know how to drive in the snow. Well after i recovered from the fishtail the SES light came on and the car started acting up, almost like it was misfiring, RPMs jumping around, sputtering, very sluggish acceleration. Usually if i put the car in park and turn it off it starts back up just fine...this time it didnt start back up, had to have it towed to a shop and as soon as it was parked it started back up. Had the shop look at it and they didnt really test much because they couldnt get the problem to happen.

This car has about 123K miles, new spark plugs, wires, distributor cap/ rotor. Before i picked it up it sat for about 7 years without much running.

I know the sending unit is probably bad because the fuel gauge doesnt work, a buddy of mine thinks it might be the fuel filter, i dont know when it was changed last but i dont know what to try next.

please someone help me

 

Sounds like ,maybe, something got wet when you hit the snow causing the problems. By the time it got to the shop, things had dried out and the problem was gone. Surprising though that the OBD didn't have a code since the SES light was on.
Pretty brave driving your third gen here in Wisconsin in winter.

 

its done it in dry weather before but only once... the SES light doesnt come back on when the car starts, i just drive careful, ive driven a pickup with no power steering and empty bed in white out conditions before

 

Have you checked the ECM for codes? With the ses light coming on it should have given some codes.

 

Either way. When the SES light turned on, while running, means that the ECM has encountered a faulty condition and the sensor or sensors initiated a Troublecode. Now when the 3rd gen is turned off then back on, if the SES is off, that means that the trouble is intermittent. So the troublecode WILL still be stored in the memory of the ECM. So jump terminals A & B and write down the codes. Then get back at us with your results. Remember, when the SES turns on and then back off, the ECM will still have that code stored until the battery or ECM power has been disconnected. Im suprized that the shop didnt get your codes. Hopefully the mechanic didnt disconnect the battery.

 

i think the codes that were popped were 12 and 34...i think

 

12 in normal. 34 is the MAF sensor. Disconnect it and clean the metal terminals inside the maf and the connection. Then reconnect turn on the car and tap on the maf. If it fluxuates then the maf may be going bad. But clean the terminals. That may solve the whole issue.

 

12 isnt a code. 12 is telling you that the ECM is in diagnostic mode and its going to spit out codes. It should go back to 12s after the codes are done.

34 I BELIEVE is related to either the MAP sensor or MAF sensor.

Im wondering if you dont have some issues in the fuel tank. Maybe the pump/filter has issues. When you fish tailed, fuel sloshed around and made something act up?

First thing Ide do is diagnose the sensors and then change the MAP/MAF sensor whichever it may be if necessary. Maybe dip into the fuel tank to see whats going on in there. At the very least make sure the filter is still in place and not blocked by anything.

J.

EDIT: SOB!! Thats twice today that a post went up just before mine haha. Im off my game. Either way info is correct. Thanks for clarifying code 34...

 

It says its TBI so it will be a MAP. Check the vaccum hoses from it to you TB and the electrical connection. Its on the passengers side on the firewall at the top.

 

give me a few minutes, im gonna go double check the codes in a little bit

 

so i just double checked the codes... its popping 43, 44, and 53

 

https://www.thirdgen.org/service-eng...ht-error-codes

 

thanks, can you possibly clearify that stuff for me though... its like reading greek to me
43. Low voltage at electronic spark timing circuit 44. Oxygen sensor lean
53. High voltage at battery OR High voltage at exhaust gas recirculation valve OR Voltage reference error OR Problem at vehicle anti-theft system

 

Code 53 is kind of stupid. GM was confused when they wrote the description for this one. You'll note that in diagnostic information it sends you straight to the VATS system, which makes sense with your no start issue. What's interesting is the other codes with it. Lean exhaust (44) could have set when you had the drivability issue after fishtailing. This would make sense if your fuel pump had sucked up some garbage from the fuel being sloshed. The code 43 means that the knock sensor and knock control system lost knock sensor signal at some point. This could have been caused by a poor connection at the knock sensor which could have been made worse by moisture getting to it.

You kind of have to take each one seperately at first. Look for any sign of trouble at the knock sensor. How's the connector look? Is the terminal corroded? Is the seal still in tact? A scan tool would be very helpful during this check out. Also, look for knock signal while tapping on the engine block close to the knock sensor with a 3/8" extension or pry bar. The VATS code will be tricky to find. Especially since its intermittent. One time when the car doesnt start, you need to look for VATS Fuel Enable, "yes" or "no" on datastream. Then test the circuits to and from the VATS module. Or just install a bypass module and delete the VATS system. For the lean code you will again want to use a scan tool. Watch O2 voltage while driving. Look for normal toggling of the signal, rich to lean. It should go rich under load and lean during decel. If the data looks normal, suspect debri in the fuel tank, a faulty fuel pump and/or relay.

 

sounds good...so all in all the most likely cause is the fuel system it seems...i was planning to do the fuel pump in the spring but i may need to do it sooner

 

Are you sure its not a code? If it aint, then why do these two reputable sources classify them as codes?

Fuel naturally "sloshes" around when you brake or accelerate.

Instead of changing the MAF, I'd rather test it out before buying a Reman from Autozone which is a couple $100 or the Dealership which charges over $1,000.

 

Ima post up your 3 trouble code troubleshooting methods. Hopefully this will help you figure out what is happening with ur 3rd Gen.

 

Now here is the description of your troublecodes.

 

How's it going ASE Doc? Might I add, Well said!

 

Well, technically 12 is a code, but none of us refer to it as a "trouble code".

12. No reference pulses to Electronic Control Module (ECM).

- means there are no electronic signals being sent to the ECM - why? Because you have shorted out the pins in the port to retreive ECM data. The ECM can't retreive data from sensors AND send stored data (to you) at the same time with this paperclip method. Thus EVERYTIME you short the data port pins you get this "code" letting you know that the ECM is not (or cannot) receive signals from the sensors.

Or at least that's how I always interpret it.

I'd start with fuel - change that filter 1st - it's the easiest cheapest thing to do. This is a TPI car right? If so, then there is a schraeder valve in the engine bay on the fuel rail - cover it with a rag and push in the pin with a screwdriver tip to relieve the pressure first, then you won't get covered with so much gas at the filter.

Then can you hear the pump prime when you turn key on? If so, then I doubt you have a fuel pump issue. You can test fuel pressure at that same schraeder valve.

O2 and EGR should not keep car from starting/running - I'd ignore that for moment, and come back to it later.

You mentioned plug wires and misfiring/sputtering. 90% of the time (in my experience) misfires/sputters are ignition related. Make sure the plug wires are all on tight, make sure none melted on exhaust. Take a volt/ohm meter and test continuity on each wire one at a time - should read almost 0 ohms - can't tell you how many "new" plug wires I've bought that had internal breaks right out of the box - manufacturers dont test continuity after the wires are cut to length, they only test the entire reel of wire beforehand.

Is this problem only ever present when the car is warm? After all that, if still exists, might try a new ignition module (it's inside distributor under rotor). They can go bad (especially from sitting for 7 years - condesation & rust) and won't present issues until they get hot - a new one comes with dielectric grease to keep the plate from rusting and make sure a good electrical contact is made.

I never tried diagnosing an O2 or EGR issue - on those I just replace parts and call it a day.

Good luck!

 

Yup. Well said. The code 12 was towards the member who stated that it wasn't a code. I replied in question form.

 

Sorry...its not a trouble code in this instance. Its basically telling you the computer is going to give you any codes that it has stored. It goes back to 12, or repeats 12 if there are no codes. He listed 12 as if he thought it was a "trouble code"...which it is not. There might be a way of reading the ECM with a snap on type tool that if it showed a 12 would be a problem. I.E. not using the paper clip method.

Sure...fuel naturally sloshes around. However his car was moving outside of normal operating conditions. He mentioned he was fishtailing while getting onto the freeway. So that could cause the car to be moving one way, and ther fuel to be sloshing the other way with more force than just normal sloshing. Basically jostling the fuel sender assembly.

As for the MAP/MAF sensor replacement comment...I did tell him to diagnose the sensors before changing them... Figured he could look that info up on his own, or that someone else would post up, as they did.

Sounds like the OP has more going on that just the one code at this point anyway. So he's gotta go through and trouble shoot step by step...just as you guys are suggesting.

 

Your talking to me like if Ive never drivin in snow before. When you fish tail in the snow, it is a smooth transition when the rear end begans to go in the other direction opposite of the skid. There is so much more G force when your skidding around a corner with the wheels spinning, then when you let off the gas, the car jerks hard as the wheels regain traction. That gripping of the rear wheels coming out of a turning skid has a far more powerful force than fish tailing in snow. Lets get back into reality here. Also IIRC, in this post, nobody said code 12 is a troublecode. The author of this thread probably wasnt aware of the meaning of code 12.

 

So code 12 isnt a code? Here is the definition of a code:

attach a code to; "Code the pieces with numbers so that you can identify them later"
In communications, a code is a rule for converting a piece of info (for example, a letter, word, phrase, or gesture) into another form or representation (one sign into another sign), not necessarily of the same type.

 

Since TC 34 came up in this thread, I might aswell post up on the TC troubleshooting method.
Pg. 90 is in a earlier post above.

 

ok guys enough debate about the code 12....it is a code but not a trouble code...there debate settled.... i was pretty sure that it wasnt relevant but i just wanted to make sure...since i started this thread i did look into it and found out that it just means that its going into diagnostic mode

 

Guys, we need to behave like adults and not highjack threads with silly debates. Ive been guilty of this myself and its just our childish egos flairing at the notion of being slighted. Each of us has some experience with these cars. Some of us have more than others. The very purpose of this forum is for us to share our experience with one another for our common benefit. And of course to celebrate the awesome third gen F-body!

cmbtmdc, your on the right track. Replace your fuel pump and do your best to clean any debri from the tank. You may also have a VATS issue to deal with. This will reveal itself with subsequent no start episodes. If you decide to go with a VATS bypass module, be sure that you buy an actual "module" and not a cheap pack of resistors. The actual "bypass module" generates the fuel enable signal commanding the ECM to activate injector drive. It costs about $25.

 

ok so here is a slight update, I have had this issue only once since I have gotten the car back from the shop, seems it only happens when i try to push the car a little bit more than normal ie going up hill and pushing the gas to keep speed up or going around turns too fast. I dont know if this helps anyone,

I recently drove it from La Crosse WI to Milwaukee WI and it made the trip with no issues but i stopped about 110 miles into the trip to clean my windshield due to my wiper fluid freezing and i topped off the tank and it only took 3.1 gallons, i did the calculations and it turned out to be 35 MPG, i continued the trip and another 95 miles later i did the same thing this time the gas mileage was about 20 MPG....now idk if this is part of the issue or what but the only thing i did was put some SeaFoam fuel additive in the tank... any help is welcome