Hello all i'm new here my name is Paul, hope some one can help me on this just bought my first vette (93) with 43K on it all original no mods, i changed the air filter and dunped some fuel injector in the tank and washed it, put it back in the garage, the car was running nice, later that day started it and it started to run rough and started making a sound like it was poping pop corn out my muffler, went to drive it and had very little power hardley could make it back up the hill back to my house it even started making a pinging noise going up hill, any idea's??

 

Your fuel addidtive may have disloged a bunch of crap in your tank, and either clogged the "sock" on your fuel pickup, or clogged the fuel filter itself. Either could cause fuel starvation. First thing to check is the fuel pressure. Do you have the factory service manuals?

 

Does "washed it" include the engine bay? If so did you point high pressure water at the optispark?

 

no i dont have any service manuals, and i did wash the engine bay taped up all the connections and did not get any water near the OPT-Spark and used a very light spray and the drove the car with no problem it was after the fact i changed the air filter and dumped the STP fuel injector cleaner in it,

 

so i guess its best just to take it to the dealer?

 

Sounds like it could be a miriad of things, that requires troubleshooting and diagnosis. Given all of the factors it could be, and if you're not equipped with the necessary tools or knowlege to troubleshoot the issue, you might be well-served to take it to a shop for diagnosis.

If you have taken some steps to troubleshoot the problem, then outline what you've already eliminated, maybe that might elicit more response on the forum.

 

If you can somewhat turn a wrench, do yourself a favor and let these guys help you get your car back in shape. collectively they have way more experience than any Stealership. I agree with 92ragtop your going to want to get the Factory Service Manuals you will need them in the future anyway.

 

belive me the stealership as you said is the last place i want to take it too, i do have some tools and i can turn a wrench i like working on cars its just been a while, and thats why i joined i appreciate everyone help, i'm hopping its something simple i will start with changing the fuel filter and see what happen's,
Thanks Everyone!

 

Avoid a dealership! They are no longer familiar with these old cars. Find a good mechanic who knows them. Local Corvette clubs should be able to help you with a recomendation. Regarding a fuel filter, they are not that easy to get in/out, (above the cat on the R side). Getting your fuel pressure checked beforehand could save you the trouble. Pulling the fuel pump/pick-up assembly out of the tank is easy though - check the "sock" screen at the end.

And yes, buy yourself the FSM (red 2-volume set) on ebay for yourself for Christmas.

 

Free and easy things to try.
Using a hose of the right size draw out a ½ quart of gas from the bottom of the tank and let it stand in a clear glass jar for a bit water should be obvious in the bottom of the jar. It will look like mercury. (try not to stir the contents of the tank as you do this)
Disconnect the vacuum line to the fuel pressure regulator. This should have the effect of ramping the pressure up to its maximum. Does the car run differently with more pressure?
Run the engine in the dark and look for spark leak light show around the ignition wiring.
Pull the fuel pump and look at the sock. Change it out while you are there since they are cheap anyway.
Pull codes using the paperclip method.
Do both exhaust pipes put out about the same when its running rough? (prolly only see a difference if it is a huge difference but it is a free check)
Cheap things to try.
Change your fuel filter. When’s the last time it was changed anyway? (note this is much much easier if done by depressurizing the fuel rail then disco the rear line from the filter, the clips on the line above the filter and it’s bracket and pulling it out the top.)
With some basic diag tools.
Check the fuel pressure at idle, with the FPR disco’d, and after shut off. (Fuel pressure tester with side discharge tube ~$55 for a good one that won’t **** fuel all over the place)
Verify spark at each plug. ($5 spark test tool)
Verify each injector is getting a pulse. (~$22 noid light)

 

Wow you guys are great this is a lot of good information i will try them, I just bought the car last week and was running fine, i will change the fuel filter this weekend, i just thought of something i did wash the engine like i said and was very careful not to get any electrical wet, but i did notice i tube on the front driver side that conects to i'm assuming it has to do with the smog system, and now its making a noise and i may have got water in it could that have someting to do with it? not sure what the hell it does but as the car run rougher that started to make noise, any thoughts?

 

also once i figure out what is wrong with my car i wanted to do sum mods to wake it up any idea's?

 

rebuild to 383
use AFR heads, match cam to heads

Probably in the $10K range
Will really wake it up

 

nice thats a little more then i want to spend right know how much HP with that set up?

 

okay guys please help me out, so i let my car sit for the last couple day's unplugged my battery, started it up idled nice both exhaust pipe blowing good, now once it warmed up it started running like crap again missing and back firing, so i also notice only on side of my exhaust pipe was blowing smoke (its cold)is this normal or is the a bad converter? what do you guys think?

 

Check your INJ fuses, if one is blown it will start and run like crap.
Mine was the INJ 2 fuse.
Get a noid lite set and check for injector pulses

Get a spark tester and check for spark at each plug

Follow the trouble trees in the factory service manual

 

thanks i will change the fuel filter and plug and wire too and see what happen,
thanks for your help i will let you know what happens,

 

no need to rebuild it to a 383 - thats where about 65% of the 10k he is quoting came from.

Test compression on your bottom end, make sure its good. If it is then:

Just slap a set of AFR 195 comp ported eliminators(these flow as much as LS3 heads), 1 3/4" long tube headers/ hi-flow metal substrate random tech cats (note: some vendors sell 1 5/8" long tubes which are too small for LTx motors), and a hotcam kit (218/228 .525/.525) / 1.6:1 roller rockers. Also need a tune, contact Alvin@pcmforless. He did my 93.

Id estimate the mods I talk about would cost about $4k (by the time you buy all the gaskets, and supporting parts you need). Probably also want to put in new optispark (only use ACDelco new old stock optispark..modify it w/ a vented harness like on the later 95-96 cars). New optispark (AC Delco new old stock - dont use the cheapos) should cost about $600. Get one while its still available.

Thats with you doing all the work.

The combo I mention above should make close to 400 rwhp.

 

Im going to guess your issue is a bad optispark.

Read my previous post about making mods to the car.

IF you are in there anyways to change the optispark, you are halfway into completing the mods I discuss.

 

hey dizwiz24 so what do you think about this, http://www.delteq.com it cost about $700and never have to worry about the OPTI-Spark let me know your thoughts,
Thanks !