No Schrader Valve on my 90 LX?

mrswivlepants

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Aug 13, 2003
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I just installed some new parts, including an AFPR but there isn't a schrader valve on the fuel rail anywhere to check pressure. I broke down and scoured my Chilton and it says it should be on the front right (passenger side) corner of the fuel rail. There's just an aluminum block there. WTF is going on? I had a mechanic search for it too and he couldn't find one.
 
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89MustangGX said:
Check back by the fuel pressure regulator -- I believe 86 rails were similar in design except the valve was back there. Maybe someone swapped them?

Yep, check all over the fuel rail. My 88 has it right behind the alt under the AC line out of sight. Can be hard to locate on some cars if you dont know where to look. Mechanic may have just been in a hurry, or its simply not there anymore.
 
The mechanic was meticulous about it. It probably isn't there. How do I go about checking fuel pressure without the valve? I bought a regulator without a pressure gauge connection so I would assume that route is out of the question.
 
Mine is in the same spot as Jerry's. you should try moving wires and stuff out of the way if they are buried behind the alt, so you can see the valve. it might have a black cap on it.

If you dont have one, about the only non-surgical way to test that I can think of is to do a volume test.

good luck.
 
Even if someone removed the schrader valve, they had to plug it with something. It just unscrews and you're left with a 1/16 NPT hole in your fuel rail.. you have to remove the valve to install your gauge anyway. Look around for a plug.
 
Follow the fuel rail toward the front of the engine. It will come away from the block, and start to head down to the passenger side header. The schrader valve is right behind the altenator. It is kind of hard to see, as the plug wires and air conditioning lines are in the way. Look for a plastic cap, similar to a bike tire valve stem cap. The cap is covering the schrader valve. You need to remove the valve and install the gauge. To attach a gauge there, you will need the correct adapter to thread into the fuel line. Call Autometer. They have the gauge and adapter for really cheap, $25 or so. Be careful, the adapters are weak. I have broken two trying to tighten them.

Damn, you ****ers are too quick. I thought I had this one. Too much beer I guess. LOL.
 
here is a pic of what you are looking for. if you still can't find the schrader valve, the only way to check pressure would be to buy a regulator that has a 1/8 port built onto the side of it. I know the accufab, BBK, and maybe the mallory one do have this port.

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swivelpants - it's there - look down under/behind the alternator.

"you have to remove the valve to install your gauge anyway. " Not mine - my gauge/fitting simply screws onto the Schraeder in place of the black cap. I only use the gauge to set/check fuel pressure. Under normal operating conditions, I don't think it's a good idea to have that gauge/fitting hanging off the the end of the Schraeder vibrating as the engine is running.
 
Michael Yount said:
"you have to remove the valve to install your gauge anyway. " Not mine - my gauge/fitting simply screws onto the Schraeder in place of the black cap. I only use the gauge to set/check fuel pressure. Under normal operating conditions, I don't think it's a good idea to have that gauge/fitting hanging off the the end of the Schraeder vibrating as the engine is running.

Michael,

I have the one from 50Resto that you don't have to remove the schrader valve either. That thing isn't going anywhere... mine is on there pretty dang tight. A little teflon tape for me did the trick. I have 1000 miles on the new motor and it hasn't budged. Just an FYi...

Tim
 
You can check fuel pressure w/ a stand-alone gauge that you can get from autozone for like $20-30. Hook it to the schrader, check pressure and unhook when you're done if you don't want a gauge connected to the line all the time.

I have one connected to my line. I had to purchase a seperate fitting, remove my valve, and attach the fitting w/ the gauge to the line.

If you absolutely do not have a schrader valve, you could simply buy a new/used line. They aren't terribly difficult to install. I got mine for $20 in the corral classifieds for both lines. I suppose you could also get a regulator w/ the valve or whatever...never researched that much, so don't know much about that. It does look like my BBK has a small thing that could be removed and I've kinda wondered what that was...guess I know now.

Good Luck.
 
I FOUND IT!!! Chilton can suck my yabbos. Turns out it was down behind the alternator as suggested. Now on to tuning....the car runs like DUNG now. Here's what I did, maybe some of you guys can help me tweak the setup or give me some guidance.

Cobra Intake
73mm C&L MAF
70mm TB
24lb FRPP injectors.
AFPR (duh)

The timing is set at 10 right now. The car runs like a dog. There is literally no bottom end and the top isn't anything to brag about. In fact it was better prior to installing all that junk (hopefully polishable junk). The fuel pressure is set to about 43 psi at the moment. As I accelerate it seems bumpy. I can feel it throughout the car. I wouldn't call it sputtery but noticeable. The car feels like it's capable of power but it's not right yet. I tried bumping the fuel pressure up to around 50 but the power still didn't show. It was less bumpy though. Anything lower than 40 made the engine knock. I'm a little concerned that my TB is too big for the application. Please no posts about how my injectors are too big unless it bears on the problem. I'm going to try bumping the timing a little but I think there is way too little power for that to be the only problem. Thoughts....
 
Have you changed the fuel pump? Your probably not getting enough fuel from the tank to feed your car now and that is why it feels like a turd. A A/F ratio gauge would help you determine that....
 
Yeah, start by bumping your timing.. try 14*, and if it doesn't ping under load, try to up it a degree at a time until either it pings or you can feel your top end getting worse or breaking up. Make sure you use 91/93 octane. Timing can make a huge difference, when I first put my heads on, my car felt like a dog until 3k, then I upped the timing from 12 to 18 and I was spinning the tires in 2nd gear at 2k rpm.
Make sure your tps is set and operating correctly, and reset the computer.
Did you check for vacuum leaks? Fuel filter? o2 sensors? how long since the last tuneup?
 
Set the fuel pressure at the stock level and leave it alone -- it's not the problem and changing it is not the solution. Set at 38-39 psi measured at hot idle with the vacuum line for the reg disconnected and plugged. Then pull the diagnostic codes and see what they tell you.