12 Valve boost increase or lack thereof..

[Rogan]

So I put a manual boost controller (basically, an adjustable boost elbow, only located in a different spot) on my '97.My 97's HX35 WGA gets its boost signal from the AFC "T" port, rather than the compressor housing's elbow.Without it, I see about 20-22psi under load, max. With it, in full boost adjustment, I get MAYBE 25psi..I also tried pinching off the WGA's signal hose, and it made no difference.With a #100 plate, full-forward, shouldn't it:A: smoke hard under off-boost conditions when the pedal is mashedB: make 30+psi boost under full load, like say, a 30mph roll, flatten the pedalI get neither of these conditions.. It'll mildly smoke under full-throttle stomps, and will produce a short, heavy black smoke puff when I stab it from a stop.. But that's about it..no, I don't want the heavy smoke, but it should be a product of the situation, no?Is it a fueling/timing/fuel-flow issue? Ideas? Discuss:

[ISX]

You answered your own question... No fuel means no power. Check fuel pressure, fuel filter clogged, etc..

[mr.mindless]

fuel pressure would be my first question, secondly I'd be wondering where the start wheel in your AFC is, then lastly I'd be wondering about timing or boost leaks.Yes, you should be getting smoke when you mat it without boost IF your AFC is advanced far enough to fuel it hardenough to get that smoke. If it's not, it won't build boost quickly and will be sluggish.You could also just have a bad WGA, allowing the WG to open too easily. The diaphragm is much weaker than the spring, I'd expect that failure to go the other way and allow too much boost.

[Rogan]

I changed the filter this morning. It was NASTY.. ... no change in boost or smoke, though.. http://forum.mopar1973man.com/attachment.php?attachmentid=5114&d=1362062217 This weekend, I think I'll take the fuel heater apart and clean it, as well.. Sent from my SPH-L710 using Tapatalk 2

[ISX]

I guess I shoulda been more detailed. I assume you stay on top of the fuel filters, meaning it could be an overflow valve. Low fuel pressure causes low power etc. You need a fuel pressure gauge just like you needed it before with the MPG issue. Changing filters and stuff should be routine and if something like that becomes the problem then you should reconsider your filter change scheduling. Meaning, it could be an overflow valve or anything mindless said. Rather than just changing parts, you need to get test equipment (fuel pressure gauge) before you jump to conclusions. I am a firm believer in finding the cause rather than doing a process of elimination, which can get very expensive. There are many people who spend thousands chasing an issue and they coulda just got some test equipment and probably found the issue much cheaper. There are other things that you could check that wouldn't require a fuel pressure gauge such as the fuel shutoff solenoid not lifting all the way or the AFC thing like mindless said.

[Rogan]

Understood.The overflow valve was replaced a few weeks ago, remember? :)I've had this truck about 8 months. This is the 2nd fuel filter in about 6000mi.. It's much cleaner than the one I took out first.. The first one I changed was about 2/3rds covered in goop.I failed to clean the pre-heater bowl back then. And this morning, I just ran out of time.. It was 26*F when I was swapping the fuel filter at 6:45am this morning, before going to work.As for 'finding the cause', I agree with that, and generally try to stick to it.. The problem now, is, that this truck has so many little problems, I'm growing tired of troubleshooting the root causes.. LOLIt's like a part-time JOB fixing screwed up $&!% on this truck, but I have no option. Selling/replacing the truck is not a financial option.As stated, the AFC has a #100 plate, and it's slid full-forward. The star wheel is also full-forward; you can stick your finger in there and move the spring back/forth a little.My '96 had a #10 plate FF, star-wheel FF and smoked like a freight train off-boost, and it was a 180 pump. This is a 215 pump with a more aggressive fuel plate and still nothing. I need a tapped banjo bolt or something to install a FP gauge. I tried to drill/tap the old overflow bolt (the one I removed) but I couldn't get the drill bit to cut the bolt for nothing.. It must be one hard-___ piece of steel..Bottom line is, this truck is my DD and work truck. I rely on it every day, and cannot afford to have it sit in the driveway. I also do not have a back-up vehicle, so I have to make due with what I have and keep pressing on.I look to you guys for help, guidance and assistance, because many of you are well-versed with many of the issues I am crossed with.

[ISX]

Assuming fuel pressure is good then and getting straight to the root cause, you can take the AFC arm out of the AFC and then put it back on and see what happens, thereby deleting the AFC. If that doesn't change anything, you can take the fuel plate completely out. If that doesn't change anything, you should measure how far the shutoff solenoid lifts, though you can do that before you take the rest out but taking that stuff out will give you all the fuel in the world so you can narrow it down easily. I hope you have an EGT gauge if you do that and drive it sanely. Then put it all back together once you narrowed it down. Actually you can try this as its pretty easy, then revert to what I just said. You can turn the key to ON and push the shutoff solenoid up so it will stay there, then loosen the screws on the shutoff solenoid itself where it mounts, NOT the 2 that mount it to the AFC. As you loosen or take the screws out, it will either already be bottomed out or if you can pull up on the thing then the arm is not hitting the back of the pump and is probably causing fueling issues. I'll make a video of this later.

[Mopar1973Man]

I tend to agree with ISX you need to check the fuel pressure. I know on the P7100 its not a damage problem but a performance issue. You might have good filters and overflow valve but maybe just maybe the pump isn't strong anymore? All this would be seen on a fuel pressure gauge. You could install a 0-60 boost gauge as a fuel pressure and be able to check you pressure over speed.

[Rogan]

Assuming fuel pressure is good then and getting straight to the root cause, you can take the AFC arm out of the AFC and then put it back on and see what happens, thereby deleting the AFC. If that doesn't change anything, you can take the fuel plate completely out. If that doesn't change anything, you should measure how far the shutoff solenoid lifts, though you can do that before you take the rest out but taking that stuff out will give you all the fuel in the world so you can narrow it down easily. I hope you have an EGT gauge if you do that and drive it sanely. Then put it all back together once you narrowed it down.

Actually you can try this as its pretty easy, then revert to what I just said. You can turn the key to ON and push the shutoff solenoid up so it will stay there, then loosen the screws on the shutoff solenoid itself where it mounts, NOT the 2 that mount it to the AFC. As you loosen or take the screws out, it will either already be bottomed out or if you can pull up on the thing then the arm is not hitting the back of the pump and is probably causing fueling issues. I'll make a video of this later.

I do have an EGT gauge.

I kinda understand what you're getting at with the FSOS, but not 100%. I'd rather try that before taking the AFC arm and/or fuel plate completely out..

Thanks

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I tend to agree with ISX you need to check the fuel pressure. I know on the P7100 its not a damage problem but a performance issue. You might have good filters and overflow valve but maybe just maybe the pump isn't strong anymore? All this would be seen on a fuel pressure gauge. You could install a 0-60 boost gauge as a fuel pressure and be able to check you pressure over speed.

yeah, I'm gonna see what I can do this afternoon, about getting a fuel pressure gauge in.

I need to see if I can find a needle valve locally, and try to drill/tap this banjo bolt again..

I found this, earlier:

This is courtesy of Infidel at DTR:

To check fuel pressure on a 12 valve:

I drill and tap the top of the injection pump banjo bolt to 1/8'' pipe

thread, then install a male x female 1/8'' needle valve with 1/8'' tubing

compression fitting in it. Boost gauge or oil pressure tubing pushed

though some 1/4'' tubing to protect against cuts and kinks to the gauge.

For a 12 valve the gauge must be at least 40 psi, 60 psi is best.

The gauge can say boost, air, water, fuel or nothing on it, they will all work excellent.

Use no Teflon tape, it doesn't work

with diesel. Instead use anti-seize or Permatex #2. Remember you are

working on the clean side of the filter, keep everything spotless.

Compression fittings with a ferrule that slips over the tubing will leak

if overtightened, finger tight with one half turn of a wrench is plenty.

The ferrule should be replaced if the fitting is ever removed.

If you can tap your manifold for a pyro tapping the banjo bolt is a piece

of cake. Just drill from the inside to keep the hole straight and tap from

the outside. You can also connect to the bleed screw on top of your fuel

filter with the appropriate adapter to tubing if you don't want to tap.

After the install start your

engine with the needle valve closed then open it slowly till someone in

the cab signals you that it's just reading pressure. If you tighten down

the packing nut under the valve handle the setting can't move. The valve

will control pulsation and buzzing and can also be shut down in the

unlikely event that you have a leak. Without a valve to restrict the flow

the gauge will pulsate so badly that you won't be able to read it in the

short time before it self destructs.

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I just called the local NAPA stores.. WH 6820 needle valve would be Monday, as they have to order from manufacturer..

I'll try to find it somewhere else locally, but it's not too promising..

[mr.mindless]

shutdown solenoid is a much easier check than any of the above, and when I was having solenoid issues your symptoms matched mine exactly. I didn't think of that.make sure its bracket is solid too. My initial sign of bracket failure was low power because the arm wasn't coming all the way up.

[ISX]

Here's the writeup I referenced in my vid. http://www.cumminsforum.com/forum/94-98-engine/569868-fuel-shut-off-solenoid-fss.html Here's a vid that should help you.

http-~~-//youtu.be/iJlxqBNYUao

[Rogan]

That makes total sense.

I can say that the pedal in this truck feels like it's not fully traveling. I wonder if it's not this exact issue, as the FSS has been replaced (it looks new) and may be way out of adjustment...

A reading example of it is that at idle position, the TPS reads 26-28 (via scanner at OBD port) and WOT shows 65-68. I don't know if this is a "percentage" reading or what. But the pedal does not seem to 'full-throttle' the truck..

I'll dive into this and check it out this afternoon after work, provided the rain holds off long enough..

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I ordered the needle valve from Fergusons Plumbing. $7. It'll be here tomorrow.

90* .125" x 27 NPT male x .25" compression

[mr.mindless]

If you adjust the FSS linkage, be absolutely certain not to make that rod too short. That's how I wrecked the bracket mounting holes on the pump on my truck.Checking that full pedal travel is full travel at the pump is a good idea too.

[ISX]

Yeah you just want it to be right before it hits the pump, it has 0.2" tolerance so anywhere within that will work, though you might be able to even go less because I measured it all with no plate.

[Rogan]

If you adjust the FSS linkage, be absolutely certain not to make that rod too short. That's how I wrecked the bracket mounting holes on the pump on my truck. Checking that full pedal travel is full travel at the pump is a good idea too.

Is there (sorry, I've not really looked) any other throttle adjustment, pedal-wise, other than the rod that goes from the linkage to the rear-section of the pump? My best explanation of how the throttle pedal feels from idle to WOT is that the engine feels like it's around 60-70% WOT, but the pedal goes no further. The pedal requires a good bit of travel to maintain 60mph on the highway, as well..

[Mopar1973Man]

I've seen it on a VE pump engine where the throttle cable was stretched enough that the throttle only traveled about 70-80% and wasn't giving a good WOT experience. I shimmed the cable with a ziptie... Owner is happy now...

[ISX]

You might have someone watch the throttle as you press on the pedal. Mine at 60 barely requires any pedal at all.

[Rogan]

I've seen it on a VE pump engine where the throttle cable was stretched enough that the throttle only traveled about 70-80% and wasn't giving a good WOT experience. I shimmed the cable with a ziptie... Owner is happy now...

You might have someone watch the throttle as you press on the pedal. Mine at 60 barely requires any pedal at all.

I'll check this in a little bit. It was drizzling and cold yesterday after work, so I didn't get a chance to check the FSS operation. It's supposed to get up to 40*F today, so maybe I can do it after work..

As for the stretched cable theory: It's possible, but the throttle seems instant from idle with no play. I'd ASSuME that if it were stretched, it'd be a little sloppy off-idle?

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Ok, I've managed to shoot myself in the butt, yet again...

So, following the guide on setting the FSS height, I checked as instructed. Sure enough, I could move the FSS ~.125" or more.. So, I turned the ign off, pulled the pin, loosened the lock-nut, adjusted the rod height, and reassembled... Guess what? Friggin' truck won't start now. Well, it'll try, but no-go.

So, I started testing voltages. Everything "seems" to be correct..

The problem now lies in that the FSS will initially pull the rod up, but as soon as the truck starts and you let off the key, it drops right back down and the truck dies..

Relay is good, wiring/voltages to the relay are correct, voltages to the FSS are correct and seem to occur correctly, just no-run..

Can it be that the FSS took a dump coincidentally? I'm SOOOO over this #$%^& truck right now..

[mr.mindless]

seems an unlikely coincidence. You sure you're getting power on the small wire whenever the key is on?with the key on, if you lift it, it should stay up. Unplug and replug the thing a couple times if it's being flakey, make sure it's making good contact.

[Rogan]

seems an unlikely coincidence. You sure you're getting power on the small wire whenever the key is on? with the key on, if you lift it, it should stay up. Unplug and replug the thing a couple times if it's being flakey, make sure it's making good contact.

I did reset the plugs for the relay and fss a few times. It does not stay up with the key on, yet there's 12v on the skinny wire.. Sent from my SPH-L710 using Tapatalk 2