chap2700

iTrader: (5)

I've been trying to figure this out for quite some time now and I'm stumpped, so I decided to post on here.

Everything started after I had issues with some installs I did.

I installed a bnr stage 1 turbo with manifold, rc 720 injs, and an Rtek 1.7, but later found that the bnr turbo had a blown seal, so I decided to put everything back to stock. Now that I drive the car, I get no power arond the 3500-4000 rpm range, as if the car is running on one rotor or the secondaries aren't kicking in, or my turbo isn't spooling. Before, when the car was running good, I would always be able to feel some type of power/jerk by the time I hit 3800 rpm of what I'm certain were the secodary injectors.

I've done a compression test, 95psi even bounces on both rotors

Checked voltage at the ecu for all injectors and they all read 12volts with key on 'On' position

I checked to make sure cat wasn't clogged, it isn't

I checked if turbo spools by hand, and fins spin fine doesnt seem stuck or hard to spin. Also no shaft play.

Checked the check valve by the tid to make sure it was facing the right way.

Checked that the flapper door at the wg opens and it does.

What should I look for that could possibly be the problem?

KompressorLOgic

iTrader: (6)

I'd suspect something wrong with one of your injectors, get them flow tested and cleaned?
double check your grounds, ring ground on block maybe add extra grounds?

you shouldn't feel anything when the secondary Injectors come on normally, it should be a smooth transition

chap2700

iTrader: (5)

They were cleaned less than 500 miles ago, I barely drive the car so I'm surprised this happened. It does feel like it's an injector problem, I just hate having to take off the uim and IC to get to them.

I'll double check the grounds later tonight, but would having a loose or no ground cause such a power loss?

I just came from double checking all the lg wires of the injs running to the ecu to make sure they were getting voltage and they are.

rotary_FD3S

The infamous 3800 RPM hesitation is almost always dirty grounds on the engine. Double check them and see what the multimeter reads. I think you set it to ohms but I could be wrong

chap2700

iTrader: (5)

How many grounds are there?

I don't recall messing with a ground while I was installing things. The only grounds I know are two on the bell housing and one under the rats nest.

Evil Aviator

So that means that you removed the Rtek and the 720cc injectors and replaced them with the stock components?

FC3S Pro v2.0:&nbsp FAQ - 3,800RPM Hesitation

chap2700

iTrader: (5)

Yes, correct.

Thanks for the link

KompressorLOgic

iTrader: (6)

one time I left the ring ground for the ecu under the upper intake manifold barly connected by the bolt threaded in like 2 turns,

and at 3800 the car pretty much shut down! tach would drop out and it would start bucking

R_PROWESS

iTrader: (3)

I struggled with this problem for around a year before realizing the resistor pack for the low impedance injectors was faulty, it somehow kept the secondary injectors from functioning correctly. swapped it out with a different one and everything was solved. Not saying this is your problem but it's something to check.

chap2700

iTrader: (5)

I'll sand down all the ground points that I can find this week and possibly add some more using the link Evil posted, thanks again.

While driving yesterday, I would go up to at least 4200 and the car would still drive, no bucking or tach dropping out, just no power.



Good idea, but I'm not using the resistor pack. I had to splice in 10ohms into the wiring harness for my injectors to work because my harness didn't come with a plug for it.

I had a similar problem before, one of the resistors was not connected correctly and only one sec. injector fired. I checked the voltage at the ecu and would get nothing for one of the secondary injectors, so I knew it was disconnected. Now I'm having the same problem for both injectors, but they both have a reading of 12 volts at the ecu. I'm certain they are all connected because I ziptied the plugs to the injectors. So that's why I'm confused.

Quick question, by the time I'm in the 3500-4000 rpm range, what should the reading on the boost gauge read?

R_PROWESS

iTrader: (3)

With that turbo you should be in full boost by then, also the primaries/secondaries stage point is load and rpm dependent, they do not stage under light throttle, but if you're under enough load they will. this is why you can free rev to red line in neutral and never engage the secondaries. It sounds to me like your secondaries are for sure the culprit. but the solution that worked for me apparently isn't applicable to your situation.

rxmiles

iTrader: (11)

Things seem to be getting complicated.
Start like this.

Make sure your battery is properly connected, revise your engine grounds, there's a few attached to your intake manifold.

I can't believe it hasn't been mentioned yet but #1 cause is usually tps sensor/wiring
Check and recheck this. I have had this issue tons of times.

Remember 3800k is when your secondaries kick in. Doesn't hurt to check your timing.

Check wiring to MAF as well.

chap2700

iTrader: (5)

So I sanded down all the grounds I could find and test drove the car this morning. I was driving and nothing changed, still no power by 4000 rpm.


However, this time I noticed my boost gauge was not moving up by the time I hit 4000. It stayed around 7psi on the vacuum side and never hit 0, or past 0 on the boost side. Only until I was on 4th gear that I would see the needle move up closer to 0 as I would go up to 3800, but by then I was too scarred to keep hitting the gas. Having read that I should be in full boost by then (3500-4000) concerns me.

If I were running on only the primary injs, would the turbo still kick in normally (as if I were running on all all injectors)?


I made sure everything was properly connected going to the battery, and it's tight. I am always checking to make sure the TPS is adjusted both via resistance and voltage, also checked it after I drove the car this morning and checks out.

I'll check the timing using the FSM and Haynes manual.

Also, if their was something up with the wiring to the MAF, wouldn't the car have trouble starting? I've had the MAF plug disconnected and the car would start up to 3k and then just die.

NativeBeggars

iTrader: (1)

Even though you're turbo, CHECK YOUR TPS. I fiddled with this issue on my NA for some time before determining once it got a little cooler out it was indeed the TPS and nothing else, after going through plugs, wires, both coils, tearing off manifold to replace each and every major ground. Itran like **** one cool afternoon and I thought. Unplug the TPS, see how it drives. It was perfect. My car even threw code 71 [S5 front secondary injector], and after having the rails, PDs and injectors all gone through, wires checked for volts at ECU and ohms at plugs, it was definitely the TPS causing the problem, and the code went away. I know it's a little different being turbo, but it's still something to consider.

chap2700

iTrader: (5)

Thanks for the advice, your problem definetly sounds like what's happening to me. I'll definetly try that asap.

If worse comes to worse I'll take off the manifold and check the wiring on the injectors to make sure they're getting voltage and probably switch the primaries for the secondaries to see if it runs the same.

I'll update as soon as I can, I'm just in the middle of midterms and don't have much time to fondle with my love hahaha

RotaryEvolution

iTrader: (30)

if the injectors were serviced between the original setup and your new one with problems, irregardless of miles if you only just started noticing it after trying to push into the secondary injectors then i would consider having them checked again.

it's not exactly uncommon to see injectors seized after having them cleaned/flowtested.

you could apply 12v and ground to each injector momentarily to listen for the audible "click", a seized injector will give no audible "click". with the key in the on position the injectors already receive power, the ground circuit is completed at the light green wires in the end of the first ECU connector. you should get the idea of an easy way to test them with that information, disabling the fuel pump to prevent flooding the engine is also a wise idea.

if they are all responsive then you perhaps have a ground feed issue, the injector ground feed is on the brass ring terminal bolted to the rear rotor housing. there is 2 black wires feeding into that ring terminal, one for primaries and one for secondaries, a broken or frayed wire upstream from the ring could give issues to only one string of injectors. this is common if the wiring is brittle and the ring is twisted too far when bolting it down, breaking the insulation and exposing the also brittle/corroded 25 year old wires. sometimes cutting this ground loop off at the head and creating a fresh one is the best alternative.

NativeBeggars

iTrader: (1)

Ben [RotaryEvolution] taught me this. You can check resistance at the injector clips, obviously. Check voltage at the ECU wires by probing them with safety pins. To double check you don't have a problem with any secondary wiring, pull the primary injector wire pins from the ECU connector and tape them off. Replace them with the secondary injector pins, being sure to keep them front to front and rear to rear. When you start the engine, if you have a secondary fuel problem it either won't start or it will slowly and run like ***. Proceed to pull out the secondary pins from the ecu plug until the engine stalls. Pull one wait a sec, if it doesn't stall, put it back in and pull the other. If it stalls then, the other injector wire is the faulty wire and you'll have to run another. This method, a few simple tools and a multimeter should do it for you. I had perfect resistance at the connectors, volts at the ECU and at the connectors. I also had continuity between the connector and the ECU. Continuity and plug voltage will require a few feet of jumper wire and some safety pins of course, and you will want to PUT THE MULTIMETRE GROUND ON THE ECU MOUNTING BRACKET IN YOUR PASS. FLOORBOARD. I'd tell you which wires to check but I don't know which pins they are on the turbo ECU. You can always match the colours of the wires if they're factory. Any gurus please chime in and correct my information if need be!

Warm your car up and drive it for a bit. If it runs like ***, pull the TPS plug and let it hang. See how it idles and how it drives and post results.

I also did a good bit of cutting ring terminals off and replacing them. It did make a noticeable difference, even before I performed these tests and determined later it was the TPS.

Bon chance!
Michael

chap2700

iTrader: (5)

Thanks for the informative responses, really appreciate it.

Hopefully I can get to work on everthing this weekend. Will update thread with results as soon as possible.

dguy

iTrader: (8)

You're not making any boost. You need to figure out what that problem is. Confirm that your wastegate arm is actually connected to the wastegate flapper, also make sure its not stuck open on your wastegate either.

chap2700

iTrader: (5)

The wastegate arm is connected to the wastegate flapper and the 'C' clip is still in tact. Is their a way to check if the wastegate is open without removing the entire turbo?

chap2700

iTrader: (5)

After checking the WG arm last night, turns out the switching actuator arm was either fully closed or opened. The arm was pulling the switching valve so what I'm guessing is that it was closed.

I had just started to take off the IC when I read the post to check the WG arm. Good thing I read the last post early this morning before I started to take off the manifold.

I took the car for a test run and it drives with a lot more power now. I think the issue's been fixed for now, but I'll let you guys no otherwise. I think I need to take the car out a few more times to confirm that it's running good.

Thanks again everyone.