Fuel Rail Checking?

[Safety Guy]

My '92 Ford shop manual describes what Vlad is talking about. I think they're the same function between B3 and B6. I'll look up the part numbers tomorrow.

Karl

[econoaddict]

Just curious, do you have injector pulse?

Once you remove the rail and empty it it will take a bit for all the air to purge out of the rail and injectors.
If I am correct you should be able to install the rail and hook up the supply line, remove the return line and regulator, crank the car and you should see fuel from one or both of the removed item locations.

Sounds like your getting fuel to the rail but not to the cylinders.

[Safety Guy]

Is there a way for me to check injector pulse? Since fuel is getting to the injector (square sectioned) part of the rail, why aren't they spraying fuel into the cylinders and starting the car?

When I have tried to start her, I've done at least four ignition tries of about a half-second each. Is that enough?

If I have no better ideas today I'll put Twin's fuel pump in Aqua and see what happens. I'm now thinking "bad fuel pump": it pumps but with not enough pressure.

Thanks,

Karl

[econoaddict]

Unplug an injector, one side of the plug should be 12+ volts key on and the other side is grounded when the crank sensor triggers. use a test light between the 2 and crank the engine, the test light should flash.
or just swap out the distributor and try it, the crank sensor is in there.

[Safety Guy]

I borrowed the fuel injector tester kit from O Reilly Auto Parts today and used the "noid light" to check three of my injectors. All lit up and blinked at me when cranking the engine. So I have power to injectors. Here was my setup, with short bungee cord so I could position the noid light in view:



Here's the kit:



Sorry it's sideways, but Photobucket does that sometimes for no reason and there're no arrows to turn it rightways.

NOTE: The "Ford" noid light did not remotely fit, but the "GM PFI" noid light fit perfectly.

Still no start today either. After testing my injectors, I then removed the front left gas tank bolt and loosened the rear left one, in an attempt to see if relieving any theoretical pressure on a fuel hose above the gas tank would allow more fuel to flow. Nope. Didn't work.

Finally, I disconnected the fuel pump wire connector at the pump cover, and then remembered to turn the engine over to relieve pressure. That's when it got a bit "weird."

When I turned it over, it sounded like it fired a bit!! Mind you, I had already removed the VAF and whole intake piping! I have no idea if the engine really fired for a moment or if it was my imagination. What would allow it to do so without the VAF hooked up? Without the fuel pump itself hooked up? Maybe I just heard more noise since the intake pipe was not covering the TB horn. (I think that was it.)

Tomorrow I swap in Twin's nearly new fuel pump and see what happens.

One more thing: O Reilly had a fuel pressure tester kit, but it was fifty bucks. I then checked to see if they had an in-car guage kit, but they didn't. (I didn't feel like spending the money on the kit.)

I'll leave ya'll with a picture:



Aqua borrowed Twin's "trophy" grille. Pretty good shape from hitting a Festiva! Only one crack on one side that I saw. This is probably getting hung in my garage.

Any more ideas, lemme know. I think I've ruled most everything out except a bad fuel pump. Tomorrow will tell.

Thanks,

Karl

[skeeters_keeper]

Hey Karl... sorry to hear about your problem with the festy, I haven't been on the forum too much lately but here are some things to clear up miss-conceptions in this thread:

both B3 and B6 FPRs are hooked to intake vacuum. higher vacuum means more "pull" on the diaphragm that keeps the FPR closed, so at high vacuum the FPR opens up allowing more fuel to flow through (because idle => high vacuum => low fuel requirements). when there is no vacuum, the FPR closes giving the most possible amount of fuel pressure. Your FPR probably isn't blocked; until you apply some vacuum to it it should be closed.
BUT
even if it was blocked, it wouldn't keep your car from running. It would just be super rich at idle. I had this problem shortly after my B6 install (bad FPR, which when they fail it usualy fails closed, => about 60psi fuel pressure on the rail instead of around 45). This gave me about 23mpg and some sweet backfiring. But it won't keep the car from running!!

My suggestion: get a cheap in-line fuel pressure gauge from HF. Install it on the "inlet" side of the rail; i.e. not the FPR (you do have the in/out fuel lines on correctly, right? FPR is the return line) Put it on and see what you get for fuel pressure.

If you still have the injectors off, get a 9v battery and connect it to the terminals. Easiest if you have an extra injector plug but you can put some little alligator clips in there if you don't. You'll hear the injector click open... if you don't, you have an issue. Now with the injector still open (battery connected) spray some carb cleaner into the intake side of the injector and watch the spray patter out the other side, it should be a nice 'cone' shape. If not you may not have a clogged injector but its unlikely that they would all clog at once.


I'm putting my money on not enough fuel pressure, i.e. bad pump or connection somewhere. When you have the lines off and crank the car it should shoot fuel out with a lot of force. The injectors need 45-ish psi to really put out enough fuel.

Hope that helps!

Nate

[skeeters_keeper]

One more thing: if you want to put an "in car" Fuel pressure gauge, do not use a mechanical one. That should go without saying, but...

The electrical ones are kinda pricey, not worth it unless going super-duper-modded. Just buy one from HF or something; its worth it and you'll use it many times!

[Safety Guy]

Thanks Nate!!

Just so you know:

-I had my injectors cleaned and rebuilt
-the noid light says I'm getting power to the injectors
-I'm getting fuel out of my inlet hose and not the outlet hose, which is how I can tell which is which. So I'm not making the mistake I did in my first engine swap (hooked up my hoses wrong on the fuel rail)

Thanks again! I'm trying Twin's fuel pump tomorrow. I'll check out the cheap HF inline fuel pressure guage. "Cheap!" That's my kinda part!

Okay, here we go from HF:

http://www.harborfreight.com/fuel-injection-pump-tester-92699.html

Looks quite like the one O Reilly's had, but at half the price. With 20% off coupon, less than half the price.

Karl

[econoaddict]

I have that exact tester for home use, has been great.
I checked it for accuracy with my Matco master set and both showed the exact same pressures when tested.

[skeeters_keeper]

yep - same one I got. I left it in-line under the hood of my car for like 3 months at one point, no issues still works fine.

[Safety Guy]

Well it must have been a weak fuel pump, because I put in Twin's pump and I finally got Aqua started!

You could say I'm happy now.

Ran her twice for about four and six minutes each. Idle began around 2000 rpm and came down to around 1400 rpm. I still have to figure out this timing light operation.

Whew. I think I'm on the home stretch to getting a decent "pre-rusted" winter beater on the road!!



Karl