My 85 vette took a dump this afternoon, sitting at a stop light and the car sounds normal then I push in the pedal and no go! oh no!!!! It gets towed home, spark is fine, air is fine, fuel I'm not sold on but looks fine, so I'm told to look at timing and to manually roll it back or whatever but anyways under the hood on the plate it says 6? DR, I wanna know what DR means and all that in relation to tdc so I don't screw something up more!

Thanks

 

I kinda doubt it your timing unless you dropped a chain, and you'd know that. I think I'd start with checking the fuel pressure first (could be the pump took a dump) and that's easy to replace, also replace your fuel filter. Most of our C4s are set at 6* BTDC, if you've got an automatic, I've heard of some guys timing their cars while in DR (Drive) I've never done it though. Make sure you disconnect the EST wire between the brake booster and the wiper motor first, it's a single wire that just unplugs. If it throws a code don't worry about it...just disconnect the battery for a few minutes and the code will be cleared.

 

6* in drive w/est disconnected, (according to the sticker). I agree w/Rick, doubt that's your problem, you will need to determine if there is fuel, since you are sure there is spark.

 

Lets take it from the top, I'm driving home the car is fine then all of a sudden the check engine light came on, but that's usually normal as it just goes away a few minutes later, well the car is running fine then I come to a red light and when it turned green I went to push in the gas and car no go lol. it stayed at the 7-8k idle speed and even with the pedal to the floor the rpm never moved, so I truck it off to the side of the ride idling along and I put it in park and press the gas again, still no go but this time it sounds like somethings a building and slight tiny popping noises from inside the engine and I didn't wanna stick around for the loud pop so I shut it off. I get it home and we put the battery on a charger to make sure over night, same problem, put in some gas, same problem, open the cap on the fuel rail and gas trickles out in a nice healthy stream, it fires over and it runs for 1-2 seconds t hen it just dies, the radiator and oil fluids are all fine. There's a strange like zapping or scraping noise coming from the alternator but not sure if that is part of this problem or not. So yea I'm in at a loss of direction I'm told to check the distributor/rotor cap whatever yea lol umm not sure if that'll be the cause of problems or not. What would cause a timing to just suddenly skip from sitting at a red light? did the computer die? anything pointing me in a good direction would be appreciated and I do hope to get it resolved fast.

Thanks everyone!

 

I gotta say, this part really stands out at me. Have you checked your codes? That shouldn't normally come on even if it just goes away. This could lead you in the direction you need to go to find your problem.

 

Yea it just flashes the 12 for diagnostics mode... where's the head scratching smiley? lol

 

12 simply tells you the ECM system is functioning normally. Lay hands on a fuel pressure gage. The fact that there is fuel at the rail doesn't tell you much about the pump or the pressure regulator.

I wouldn't start messing with timing until I check out the fuel system.

 

well I should also mention now that I remember I have had a reoccuring TPS code in the past but fiddled with it and haven't had a problem for some time, and I will try and get a fuel gauge to double check that.

 

2 tools.

Fuel pressure gauge to see what the pressure is. Hopefully you can tape it to the hood and do a WOT run or as large a run as you can get

Scanner. Check the TPS voltage.

 

ok I changed the fuel filter and checked out all the plugs/wires/distributor and fuel pump all looked fine to me, I'm wondering if the TPS could cause such a thing or maybe an injector or the fuel regulator. the car starts and all but dies 3 seconds in unless I start pulsing the gas pedal, just in and out at a steady rate then it revs up like it wants to go and hits like 3k rpms and starts missing and backfiring then when I let go it just dies again like it's being starved of something... I just wanna get the last ride in before winter!

 

TPS could cause it which is why I said to get a scanner. Either that or you need a DVOM to check the voltage. 3 wires. 1 ground, 1 5V reference and the last one is the signal to the ECM

 

Ok I checked out the TPS and as the repair book said put the car in the on position and the voltage at the B terminal should be .5 volts it is, but it says that if I slowly open it to WOT that it should go up to 5 volts. it doesn't move. So does this mean that the connector is supplying the power but the TPS kicked the bucket and is no longer regulating the voltage like it's supposed to? I hope so lol I've checked EVERYTHING on this car...

 

Sounds like a faulty TPS.