Charles, just the innards unscrew out of the valve. It is the same as a tire valve and at one time, they use to have valve caps that had the tool on the top to use to unscrew the valve.

 

Be very careful with" pressurized gasoline" as it will vaporize very easily and that makes for a potentially explosive situation. I would only do this job if you have a Fire Extinguisher handy and are working outdoors away from any buildings. I strongly suggest that you don't push the shrader valve pin down while it is under pressure as this is also a great way to start a fire, use a pressure gauge and be safe. Don't test injectors with them pulled out of the intake either as the gas vapor would be extremely flammable. Use caution and be very careful when working around the fuel system. Some auto parts stores will lend you the fuel pressure gauge for a day or two if needed.

The schrader valves don't fail very often from what I personally have seen. Like wisely suggested by Puple92 you can remove the shrader valve assembly and attach the gauge directly to the port, just be sure to put the shrader valve back. Use the Fuel pressure gauge's ability to bleed off the pressure so you don't do it in your face when you loosen up the pressure gauge fitting. Once you get the FPR diaphragm replaced we hope that your fuel pressures will be okay.

The idea of applying power directly to the fuel pump to see it work is a sound one. If the pump works and primes the fuel lines you know the problem is between the Fuel Pump and it's source of power. I found a bad connection going to my Fuel Pump relay doing it this way. I have a tool called a Power Probe that lets you apply either full battery voltage or ground at the tip simply by moving a rocker switch on the side. It is a very handy tool on Corvettes and I use it regularly on both C3 and C4.

On the fuses you buy for your C4 be sure to buy a name brand fuse. I once had a (CHEAP Chinese Junk) set that I installed in place of the originals and in a couple years they would not conduct electricity. It seems that they corroded and there was a fine layer of corrosion was enough to keep the power from flowing on the surfaces of the fuses. If I scraped them they would work but unless cleaned off they were useless. They looked fine and tested open, weird problem. I then cleaned the terminal connection on every fuse socket as well.

We are all awaiting news that your Corvette is running like a "Raped Ape".....Good Luck and be safe!

 

Thanks CT for all your detail. The FP does prime and I get gas out of the line before and after the filter. The fuses are not blown. I picked up the FPR this morning. I am awaiting my noid light as well to make sure injectors are energized from the ECM. I think that makes a huge difference. IF the injectors are not being pulsed, the I think I looking at the ECM. If the injector pulse is present then this may implicate the FPR. I hope hope hope to have this sorted out soon.

Thanks again

 

And a note to everyone on here. Thanks for taking time to make my problem something you take serious to you to respond. I am very much a newby. Trying to learn and not be a pest.

Thanks again

C

 

Charles212 - We were all Newbies at one time, and we all learned - sometimes through the help of others - sometimes the hard way, but we learned...

The amount of knowledge available on this forum is truly amazing.


If you have spare tire available to play with - as powerplay2 said - the schrader valve comes out of the fuel pressure test port just like it does out of a tire - so take the valve cap off, insert the valve core removal tool into the valve "stem" - slowly twist it till it engages the valve core - and then just unscrew it. It's really really simple. To reinstall - just reverse the procedure - but if you are playing with a spare tire - wait till the pressure is one before you reinsert the valve core....

You already know that you have spark. The three things an engine needs to run are:

1. Spark at something approaching the correct time.
2. Fuel
3. Compression.

I expect that you're going to find the Fuel Pressure Regulator is bad, or that you have no injector pulses. There is a possibility that the gas in the car was ancient, and it gummed up the injectors - but that is not that likely...

Let us know how you make out....

 

The Ignition Control Module inside the distributor has something to do with the signal Pulses. Under the rotor is an electrical component that has several wires attached to it. This device I think is ICM and i am pretty sure that is the first thing to look for if you don't see pulses.

Don't be so anxious to replace the ECM, they don't fail as often as the simple stuff does.

Replace the FPR diaphragm while you have time! Anxious to hear how it works!

 

^^^ This ^^^

I'd mentioned earlier in the thread that this is very likely where OP's issue lies.

 

I will Never say "It Can't be a Bad ********, because the car #############"; been around the block a few too many times to think that - but the OP said he has spark - so I've been thinking fuel related. Once he does the Fuel Pressure regulator, and gets the noid lights to verify that the injectors are being told to fire - he'll know a lot more.

The other issue is that it seems that there are a lot of POS Ignition modules out there - I've seen lots of threads lately where a replacement Module is bad rihgt out of the box, or fails within a very short time. So - Personally - I would hold of on changing that until I KNOW the fuel system is functioning correctly.... Now - if he noid lights show the injectors are NOT being told to fire - then we may need to be looking at the signal to the computer.

 

The last couple of electrical components I've installed have been dead right out of the box.

Seems to be occuring more frequently. Either that or I've just been the unlucky one.

I was particularly annoyed by the hugely overpriced headlight control module, that was over a hundred bucks and lasted just over 6 months. After inspecting the cheap soldering job on it, I'm surprised it lasted as long as it did before frying. I ended up buying a thirty year old Made In USA used one from someone on the forum and it's been fine ever since.

Sensors are hit and miss, too. The last sensor I installed was shot right out of the box.