Checking Fuel Pressure on 1.7 D-Jet?, Need a "little" help here... Options

[customstarr]

I'm chasing a "rich over all loads" condition, and I'm down to the MPS and Fuel Pressure. Car is a 1971 with D-Jet.

My questions are:

1. Where do I tap in with my gauge? Do I check both rails?
2. What is the proper pressure (30 PSI)?
3. What direction is the regulator adjuster turned to +/- the pressure?
4. Any clearly defined procedure?

I did do a search and found a couple of related posts, but no direct answers.

Thanks!

[computers4kids]

I'm chasing a "rich over all loads" condition, and I'm down to the MPS and Fuel Pressure. Car is a 1971 with D-Jet.

My questions are:

1. Where do I tap in with my gauge? Do I check both rails? Assuming all is stock, tapping in off the rail that goes to the cold start valve.

2. What is the proper pressure (30 PSI)? 28 psi is kind of what I've always heard

3. What direction is the regulator adjuster turned to +/- the pressure? I believe clockwise..even though that seems backwards

4. Any clearly defined procedure?

I did do a search and found a couple of related posts, but no direct answers.

Thanks!

Are you sure it's not your TS2 (head sensor) going bad? A fautly sesnor could richen all conditions...however it's probably your MPS not holding a vacumm. Try sucking on the tube to the MPS and see if it holds a suction...don't suck to hard you could pop a diaphram. The best way to test is with a vacumm pump at 15lbs.

[customstarr]

[quote name='computers4kids' date='Jun 17 2007, 04:19 PM' post='912472']
[quote name='customstarr' post='912460' date='Jun 17 2007, 04:26 PM']

Are you sure it's not your TS2 (head sensor) going bad? A fautly sesnor could richen all conditions...however it's probably your MPS not holding a vacumm. Try sucking on the tube to the MPS and see if it holds a suction...don't suck to hard you could pop a diaphram. The best way to test is with a vacumm pump at 15lbs.
[/quote]

I'm testing the MPS tomorrow with a vacuum pump/gauge. The CHT sensor looks good (checked per specs with meter).

Just for the record, I've covered the basics: New points, condensor, cap, rotor, plugs, wires, coil, battery cables & terminals, ground straps, battery, vacuum lines, fuel filter, TS1, and more... all Bosch parts. Also checked and adjusted valves, timing, points, etc.

I prey to god that I'm in the final stretch - I'm getting so sick of wrenching on this car versus driving it, I'm just about ready to put it on the sale block. It's a nice car, and the engine is soild, but this rich condition/poor & inconsistant idle crap is testing my will. Damn you D-Jet, damn you!

[BMXerror]

I did major battle with a '70 with D-jet. I know what that's like. I would agree with you. Make sure you have everything set up correctly before checking for a faulty piece. That's what turned out being my problem. I had the CHT sensor hooked up wrong. So I would double check all the wiring and fuel lines to make sure they're hooked up right, as well as properly calibrated.
Now to your questions.
1. The pressure is to be measured on the driver's side fuel rail, between injectors 1 & 2. There's a tap that's plugged with a screw. Unscrew it and attach a fuel pressure gauge (preferably about a 60 PSI gauge) with a rubber fuel hose.
2. Proper fuel pressure is 29 PSI, although it'll rattle around. 29 PSI average.
3. Adjustment screw clockwise = more fuel pressure. Adjustment screw counterclockwise = less pressure.
4. As for procedure, Haynes manual says to unplug your primary ignition cable and crank the engine with no spark to set it. I however, have always just done it at idle and have had no problems. If you can get it to idle, great. If not, get some help and do it that way.
Feel free to PM me if you need any further help.
Mark D.

[BMXerror]

Two more things. 1: Nice garage and beautiful car. 2: Where did you get a new TS1?
Mark D.

[customstarr]

Two more things. 1: Nice garage and beautiful car. 2: Where did you get a new TS1?
Mark D.

1. Thanks - much appreciated.

2. I've been getting most of my Bosch parts from AutoHaus AZ - http://www.autohausaz.com/

Just wondering - the "tap" or "valve" on the fuel rail is very small compared to most, do the pressure gauge kits usually have that size adapter included? I've heard of guys tapping directly to a fuel line with an el-cheapo guage. What about that method?

[computers4kids]

Two more things. 1: Nice garage and beautiful car. 2: Where did you get a new TS1?
Mark D.

1. Thanks - much appreciated.

2. I've been getting most of my Bosch parts from AutoHaus AZ - http://www.autohausaz.com/

Just wondering - the "tap" or "valve" on the fuel rail is very small compared to most, do the pressure gauge kits usually have that size adapter included? I've heard of guys tapping directly to a fuel line with an el-cheapo guage. What about that method?

I don't know if you have a Harbor Freight near you...but they sell a real cheap fuel pressure testor kit with all the fittings needed to tap into the fuel line off the driver's rail that leads to the cold start valve.

[BMXerror]

Two more things. 1: Nice garage and beautiful car. 2: Where did you get a new TS1?
Mark D.

Just wondering - the "tap" or "valve" on the fuel rail is very small compared to most, do the pressure gauge kits usually have that size adapter included? I've heard of guys tapping directly to a fuel line with an el-cheapo guage. What about that method?

That'll work too. If you did that, you'd want to T it in between the 1/2 fuel rail and the pressure regulator. You'd probably get a slightly more consistent signal that way. As for the 'el-cheapo' gauge, I don't think it matters that much. Just make sure it seems to be working properly, and make sure it has a good enough range. On ANY gauge your most accurate readings will come from the middle third of the gauge. So, ideally, you'll want a gauge that maxes out at twice the value you should be working within. But still, I know how it is. I personally use a 30 PSI gauge to measure 29 PSI fuel pressure because that's what I've got.
Your car shouldn't be SUPER rich and undriveable if you're anywhere within +- 3 or 4 PSI, or else you've probably got another problem. Still, make sure it's set up right before assuming a faulty component.
Mark D.

[customstarr]

I don't know if you have a Harbor Freight near you...

Funny you ask... my girlfriend (go figure?!?) has suddenly become addicted to our local Harbor Freight. Don't ask why? She's an interesting girl.

Is this the one: http://www.harborfreight.com/cpi/ctaf/Disp...temnumber=92699

[computers4kids]

I don't know if you have a Harbor Freight near you...

Funny you ask... my girlfriend (go figure?!?) has suddenly become addicted to our local Harbor Freight. Don't ask why? She's an interesting girl.

Is this the one: http://www.harborfreight.com/cpi/ctaf/Disp...temnumber=92699

Bullseye! The kit goes on sale for $7.99 periodically. The gauge will directly screw into the silver T fiting that I have circled. Fuel line will go on all the way and seal nicely. Either leave the gauge on all the time or put a plug in the fitting when not using. The gauge dial is quite a bit larger than the ones you see on ebay...but easy to see.