wildthingsexotics

Ok I am new the whole Corvette ownership an how they tick. I trade a bike for my corvette. Here are some of the issues i am having. First was the cluster it didnt work i took apart souldered a few connections an an it started working well most of it anyway no rpm or speedo information middle works now an lights up.

#2 car will start but running very odd rpm bouces around or stalls or idle really high also if you just push gas pedal like to rev up engine it will die unless you feather it an slowly add rpm it will die if you just stab gas pedal. What i was told already done New fuel Pump An filter Spark Plugs wires he gave me havent put on yet I was looking at firing order an it looks not correct but i could be just not looking right so a picture would be great i have diagrams

Anything else I may need to know about these cars an a cheap place to get some parts. like interior parts an seals. a/c fan control **** i want to restore this car all the way.

#3 I have my driver side head light when you turn on lights it turns up an turn down an up an down an then stays up but not all the way an when closes it either closes to much or not enough it is not flush like the passenger side.
#4 wipers work but really slowly an barely move like they are stuck would that be the switch or the motor or maybe both3

Any help would be greatful I do not want to throw parts at it an waste money but replace whats needed an then upgrades when car is running an works.

leesvet

Well, if you do not want to waste money then you bought the wrong car...
Corvette parts can get expensive...quick. A lot of this stuff is not made anymore so you pay whatever they ask.

before you buy ANYTHING, go buy a FSM ( factory service manual ). The real one cost around $100, is 2 books and you cannot restore or fix a Corvette without it.
The $19 book from autozone is NOT a manual. That is a doorstop.

Find your used parts on FleaBay. Hundreds of Vette salvage sellers there. Again, you pay what they ask since they often are the only one with the part you need...

Get your FSM set before attempting to fix anything.

Get some catalogs from the aftermarket sellers. They have a lot of parts but they will be expensive....Eckelrs, MidAmerica, Corvette America. Most have websites.
Good luck and welcome to the world of Corvettes!

ya gotta love 'em !

ProjectC4

Headlight motors have a relay pack forward of the left wheel well inboard under the vacuum ball. Get the factory electrical suppliment manual, the one with the color wiring diagrams and explanations of how each system works. Also the factory shop manual.

Tom400CFI

2. 80% chance or better that your fuel pump is failing. STEP 1: GET A FUEL PRESSURE GAUGE ON THE THING. Then report back your findings. Pressure should be 9-13...these like 13-14 generally, the best. I don't care that is "may" have a new pump. Check it. For firing order, do a google search from "Small block chevy firing order". Click on "images". You'll get all the pictures that you could ever want.

3. Take the headlight motor off, take the "gearbox" end apart. The "ring gear" inside is beat. There is a "bushing kit" that you can buy to fix it, or buy a new gear. Or do what I did and fill the gear w/epoxy. Cost nothing, works great.

4. Easy. Test for voltage at the wiper motor when the wipers are turned on. Do this by "back probing" the harness/plug @ the wiper motor so you can measure the voltage while the motor is running. If you haveat or VERY near your battery voltage, you have a bat wiper motor. If you have lower than battery voltage (by .5v or more), then you have bad wiring or connections between the battery and the motor. Start tracing back, running the same test.

wildthingsexotics

Ok last night I went an checked the firing order put motor at top dead center. Took dist cap off checked wires all where ran correctly. Pulled plugs all were gapped wrong at. .20. Regapped at. .45. Put all back together. Ran for a bit noticed still ran poorly. An exhausted manifold was turned bright red. Cut vehicle off let cool an left alone.

LastC3AZ

To Tom's point ... check your fuel pressure ....
With this kind of project, after getting your service manuals to help direct you, I would go through everything before running it too much .... top of the list is vacuum lines .. electrical connections, etc .... make certain everything's plugged in (and not leaking where vacuum is concerned) .... test your EGR and filters ..... that's probably the quickest way to learn the car instead of just chasing problems ...... IMO
Good luck with the project .... and have fun ....

wildthingsexotics

Ok guys I have ordered an fuel pressure testing gauge and FSM however I have been tinkering a bit with normal mainenance plugs wires cap rotor cleaning throttle body oil things i would normally do when getting another of any type. I did stumble on to a few things i will report here an see what else i should or could do while waiting on items ordered.. I checked cat no blockage actually no inside of cat it was hollowed out..... did finally get some codes 33 an 44 I have checked vaccume lines even took a cigar an blew smoke in them to find only one hose not connected up by the headlight driver side. Now I was checking the TPS an put volt meter on it in middle wire an grouned other probe it red .20 an when WOT 1.85 to 1.93 never settled so I unplugged it On the map sensor I unplugged the Vac line an it picked up idle an would actually stay running for a bit. it would still die when pushing throttle WOT but would idle. SO is there anything else I can do besides sit an wait for TEsting tools an book.
Also what is the best way to check the EGR

wildthingsexotics

I also pulled AIC an they were dirty I could not move by hand But if plugged into wire Harrness an turned key the plunger would pull back not sure if this is correct or not.

Also I did find I guessing the fan relay on firewall by brake booster the connector was oil filled an grime an the actual connectors in the plug they were loose moved back an forth working on that also.....

Tom400CFI

TPS should read ~.5v at idle and ~4.5-5v at WOT...so you have a problem there. If the sensor is moving through it's range, mechanically and it's being supplied by the proper voltage (5v) then it's bad. Replace it.

Checking the EGR. With the car idling, reach under the EGR diaphragm and push it up w/your fingers. Car should die. If that happens, then that is evidence that the valve is able to open and close. NOT PROOF, that it's closing and sealing all the way, but playing with it should tell you a lot. Second, if it passes that test, then apply a vacuum to the diaphragm (car not running here), then plug off the vacuum source, and see if the diaphragm holds. If it holds, the EGR passes the test. If it leaks off, no good.

wildthingsexotics

Thanks Tom. I double checked to TPS I adjusted all the way up an it would read. .51. An wide open throttle it would read 2.67ish. Never ever got close to 5.0 volts. Also I checked map sensor. Only one wire unplugged had 5 volts on it. Other nothing. Is that ok. An now I. Checked fuel filter it is new an clean. But it does seem that the rear injector on tbi. Is not spraying as well as The front injector. Seems to fade in an out. Is there something I can do to check it until fuel gauge comes in. An. Any other advice is greatly appreciated. Hanks again slowly I am learning about my new car.

wildthingsexotics

can anyone tell me why my corvette run better not great but better when i unplug the map sensor idle picks up

also i did check I do have 5.21 volts running to TPS on the green wire I think top wire an .51 idle 2.67 WOT

an map sensor has 5 volts on one pin unplugged

no pressure gauge yet still waiting

Tom400CFI

No. We are waiting to hear the results on your FP test.

I guess in the mean time you could look around for vacuum leaks (common on a 28 year old car), double check the condition of your cap/rotor/wires/plugs, do a compression test to confirm the integrity of the motor.

Running better w/the MAP unplugged from a vacuum source just tells ME, that something else is F-ed up. Fuel pumps are probably the most problematic thing on a CFI engine.

Ron Rico

I am having the same issue with the fuel pump, since my 1984 C4 now has a 4 barrel has anyone heard of placing an old school push rod fuel pump on vs the replacing the electric pump in the tank?

wildthingsexotics

Ok i pulled the TBI's apart yesterday they were dirty an the gasket was a home made gasket it was blocking off the fuel pressure regulator port clenaed injectors an replaced o rings car fires up now no problem can rev up motor now with out dieing out the only problem is idle now it will not idle unless I unplug map sensor vacuum line it will idle great with unplugged i replaced map no change in performance so a little confused it runs rich now which it should if the ecm cant get a responses of manifold pressure.... so why is it the car runs better STILL after i unplug the VAc Line even though I figured out fuel delivery problem.

wildthingsexotics

Tom400. I put a gauge on the fuel line. Before the filter needle of gauge barely moved. After filter. Needle still barely moved. At tank. Needle still barely moved like 4psi. In all spots. Is my gauge broke. Or is that correct. Can my corvette run on that low of psi. I can see injectors as I push throttle the injectors open up an push more fuel. So can the gauge be correct. I tried two gauge both same results.

qws

FYI- don't hijack the OP's thread.TBI vs a 4 barrel are 2 different animals.

Tom400cfi is helping him out... btw to the OP.. trust Toms input.. he knows his stuff!!

ex-x-fire

Tbi engines like cfi will run on low fuel pressure but not very well. They usually stall when the throttle is opened. Try pinching off the return side fuel line at the rubber section, look for pressure to increase, if not make sure the pump is grounded good & getting 12 volts, if so then replace the pump, pump sock (filter), & fuel filter.

wildthingsexotics

Well from all the normal maintenance I did an found a few problems fixed those an replace the cheap airtex fuel with. A ac delco pump an car runs correctly now like a champ. Thank you everyone who contributed to helping me out I will now run some fuel cleaner an some oil treatment. For a bit change all fluids again an plugs an fix a few cosmetic issues hopefully I will stay running strong for awhile.

Tom400CFI

Which is why I insisted on a Fuel pressure reading. You found the problem; a bad pump.