loss of power at 5000rpm under boost

[rstare]

Yes, you could use the AFPR and not connect a vac line.
When I had my FDC installed I experienced something similar to what you're saying, once it got to 3psi it just hit dead. However, it was a violent shaking. I think you would know if you were experiencing fuel cut. There's a difference between loss of power and fuel cut. (I had a weird situation where my FCD actually caused fuel cut, but lets not get into that) However, at this point I would start trying anything you can think of.
You might not throw a code if one of your sensors is just putting out an incorrect signal, as long as the signal is still within a specified range.
I doubt your injectors were harmed from the amount of methanol that ran through them, but like I said, at this point, I would start trying anything you can think of.

 

[starfish]

I'll try all the sensors I guess it could be any thing at this point!I have another working motor with all the sensors,its just a pain in the ass to check them all.

I call it fuel cut because it seems like at 3psi the motor stops getting fuel all at once.my a/f gauge goes from rich to lean(---)all the way.Like the fuel is cuttin off for some reason

Its definately something when the motor sees boost .If I disconnect (loosen) a coupling on the intake the motor wont make boost, but the problem disapears,

 

[rstare]

That's because without boost your engine doesn't need as much fuel for good combustion.
You're not getting enough fuel in boost, so you have to look at the things that change or control while in boost. FMU would seem like the next most likely step, to me. Since you have the FCD, just put it in and see what happens.

 

[starfish]

on the way home from work it seems like it is getting worse.I think I smelled gas.I opened the hood and was checking around my injectors.I wiggled one of my injectors and it seemed real loose and as I wiggled it the motor started idling real bad.so I pulled the connector off and it got worse,so I dont think its the conector.do you think I could be loosin fuel pressure through bad o-rings?

 

[starfish]

I think I found out why I'm runnin lean under boost.I took off my Blox FMU just to see if anything was wrong inside.The diaphram on the fuel side has a 1/4 inch hole cut through the center,and the o-ring was pinched in half!So I searched around and tried to find out which fmu is a good quality product.And I decided to go with a Vortech 12:1 FMU.Has anybody used this FMU with a turbo?In the ad they talk about it being used with a supercharger.

 

[VelocitàPaola]

The Vortech FMU is the original... it's a quality product. I run a Vortech FMU myself. All others, including BLOX, are knock-offs.

 

[starfish]

Well I put on my new Vortech FMU thinking that was the problem,But I still have this fuel issue!I have been driving the car every day for 3 months now and I cannot figure this out.If I give the car to much gas,the car hesitates and my WB gauge goes lean all the way.I can drive the car all day without any problems if I give it alittle gas at a time.but I cant floor it!I have a couple motors so I switched every sensor and nothing helps.I tried 2 different sets of wires and I get the same shit.I even put in colder plugs.Not one single code has come up within the mounths ive been driven it.I still have my FCD,but i haven't put it in because every bodys been tellin me its not fuel cut,every time I give the car to much gas the car is just not gettin any gas.I even tried a different set of injectors(stock).As soon as I get into boost it seems like the injectors stop working.Somebody please help!I'm dying over here

 

[nosdsm3]

I am still in the same boat as you. I found a local guy that is dsm specific, his 420a is dynoing at 426 hp. I am going to him will let you know if he can figure it out, I just dont have the time.

 

[starfish]

have you tried the FCD?

 

[nosdsm3]

Have it on the shelf, have had no time to work on it. Been working way to much! Bought a new truck last week and have been using my spare time to do a few small upgrades on it. This weekend I will put it in and let you know.

 

[starfish]

OK,I put on my FCD and adjusted it perfectly and it did not help at all!I'm going to try to explain this best I can so everybody can understand exactly whats happening.I find it hard to belive that I'm the only one that has this problem.I'm using the same basic components as everybody else,and my motor is in great condition.I can drive the car giving it a little gas (no more then half throttle)through all the gears without any problems.It even makes up to 7psi boost as the motor revs up while i'm drivin,without going lean at all.But as soon as I give it full throttle,or more than half throttle it goes lean all the way on the gauge and looses power.As soon as I let off the pedal and give it a little gas it goes back to normal.If anybody has any Idea what this is ,please help me out.The person that gives me some info that will fix this problem,I promiss you I will send you a $50 money order for helping me out!

 

[bullettdsm]

The person that gives me some info that will fix this problem,I promiss you I will send you a $50 money order for helping me out!

Find the boost leak and send me the $50

Seriously, do a BLT and tell us what psi it holds and for how long.

MB

 

[LD25Delta9]

Replace the plug wires. Lemme know when you need my address... This is the EXACT problem I had when I first set my turbo up. I was using some DIY MSD wires and due to my horrible spark plug making skills, it was causing nasty misfire. Complete with sputter and loss of power. I'm telling you, go to your local auto parts store and get the best they sell. I have Borg Warner from O'Reilly's and they work. Completely got rid of my misfire/loss of power issue. When you want to drop real cash get some Granatelli's. They have about a 2ohm resistance. Check this page out, do some of your own testing with an ohm meter and see what you come up with.Spark Plug wire comparison

 

[bullettdsm]

Replace the plug wires.

Wait a sec Adam, I thought he did all the basics already? Are we saying he hasn't done the basic tune up stuff yet (plugs, wires, filters etc.)?

Gotta start with a good base.

MB

 

[LD25Delta9]

He has, I remember reading it in one of his earlier posts. But I'm blaming it on the Nology's. I've never heard a good review for the 420a from those.

 

[starfish]

Ive tried the Noligys,Stock 420A wires,and now I have msd's,Denso double platinum PK20PR11 #4 plugs.Theres no misfire or FC but when I give it too much gas it feels like the motors not gettin fuel.and every time it happens I smell raw fuel.I'm making boost with no problem when I let the motor rev up slowly.Pretty sure there is no boost leaks.I resealed all intake gaskets.all new o-rings on the injectors,checked all lines and couplers for leaks.IT even happens when I first punch it ,before I start making boost.Ive been driving it every day for like 3 months and it runs great without any problems as long as I dont give it too much gas.No nocking or pinging and doesn't burn a drop of oil.The oil is as clean as the day I changed it 3 months ago(allmost 2000 miles ago)Had it up to 110 mph giving it gas slowly,boost was steady at 6psi.As soon as I got around 5000rpm she got lean on me so I let off the pedal.Even though I cant floor it she still pulls hard under boost.I just cant slam the pedal down through the gears.

 

[nosdsm3]

Just put in my treadstone fcd today and my car is running great. I drove it for about 10 miles. On the way back it overheated so one problem solved another to go.

 

[starfish]

Do you have a wide band?If not you are probaly runnin lean when you give the car too much gas(same as me).My car will also overheat if I give it too much gas and not watch my WB gauge.

One thing that I was thinking about is my fuel pump conection.I used the original clamps that were on my stock fuel pump.When my FMU closes up could I be loosing fuel pressure at that little hose that connects the fuel pump,at full throttle?With a HP pump shouldn't I be using fuel injection clamps or does it matter inside the tank?I cant figure out where that raw fuel smell is commin from.It only happens under a load when I give it too much gas.Thats when it gets lean on me.

 

[LD25Delta9]

Do you have a wide band?If not you are probaly runnin lean when you give the car too much gas(same as me).My car will also overheat if I give it too much gas and not watch my WB gauge.

One thing that I was thinking about is my fuel pump conection.I used the original clamps that were on my stock fuel pump.When my FMU closes up could I be loosing fuel pressure at that little hose that connects the fuel pump,at full throttle?With a HP pump shouldn't I be using fuel injection clamps or does it matter inside the tank?I cant figure out where that raw fuel smell is commin from.It only happens under a load when I give it too much gas.Thats when it gets lean on me.

You've been running an HP pump without the proper clamps? Wow...I'd say a fuel pressure test is in order. About the only way you are going to be able to see what it's doing under load is with the front jacked in the air and a friend checking the gauge. If you have a late 96+ model fuel system, you use the schrader valve on the end of the fuel rail...not quite sure of how to do it to a 95/early 96 system though.

 

[#40Fan]

One thing that I was thinking about is my fuel pump conection.I used the original clamps that were on my stock fuel pump.When my FMU closes up could I be loosing fuel pressure at that little hose that connects the fuel pump,at full throttle?With a HP pump shouldn't I be using fuel injection clamps or does it matter inside the tank?I cant figure out where that raw fuel smell is commin from.It only happens under a load when I give it too much gas.Thats when it gets lean on me.

Didn't you say that it would act up even before it started making boost when you mash the pedal? The FMU won't start building the fuel pressure until boost is seen.

Yet, checking the fuel pressure while driving would be a great start.

 

[starfish]

I put injector clamps on my pump ( were the puump connects inside the tank).The rest of the fuel system all have the proper clamps.DID NOT fix the problem.Yes,It still goes lean on me before I go into boost.If im sitting at a light, and I just punch it It goes lean right away before I even start making boost.I bought a Fuel gauge,chrome mounting cup for the hood and braided lines,but I cant find a fitting that fits onto the valve on the fuel rail.Is there a company that makes that fitting on the fuel rail so I can hook up my gauge permanently and mount it on my hood.

 

[LD25Delta9]

It's a standard schrader valve.

I just read through your entire thread and about the only thing I can think of is possibly your new ecu. Where did you get it from? If by some chance it's an AFX unit, then it could be due to the more aggressive fuel/timing maps. I can't say for sure exactly, because I have never ran it myself, but I'm at a loss. I would say that Bullet would be dead on, boost leak doesn't cause a dead drop in power unless you blow a coupling. And it wouldn't let you build to 7lbs steady, either. Are you sure you have stock injectors? I'm not ruling anything out at this point. The 420A is such an easy platform to work on because it doesn't have alot of bells and whistles. If you have replaced all of your sensors with known good ones, and been able to rule things out with the proper tests, this has got to be more confusing than my "dreaded wub wub" thread.

 

[BlackMount]

just my 2 cents but, I had a similar problem one my 1st Gen 4g63T where I would loose power after mid range...turned out to be bad ignition timing.

I don't know anything about the 420A but if you can adjust the ignition timing which I'm sure you can I would look there.

Otherwise Your probably leaning out.

 

[LD25Delta9]

just my 2 cents but, I had a similar problem one my 1st Gen 4g63T where I would loose power after mid range...turned out to be bad ignition timing.

I don't know anything about the 420A but if you can adjust the ignition timing which I'm sure you can I would look there.

Otherwise Your probably leaning out.

It's not just midrange, it's whenever he gives it full throttle. The WB is telling him that it's going lean, which is very peculiar for his setup.

 

[nosdsm3]

Still have not put in my eugo. Why dose running lean if I am, make engine temp raise so fast. It is running good with very little if any hesitation.