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jordandalley 12-04-2009 08:12 PM

Surging/Hesitation at WOT
 
Hi all. It's been a while since I posted up on here but I need your help to find an issue I have been battling with for ages.

To give you a rundown of my car, it is supercharged with a vortech v2 blower and matty's v1 plate. It is intercooled and has headers etc. It is running a measured 10.5 psi of boost due to the intercooler piping volume lowering it. The pulley is 2.87". Boost is lower now that I have 3" charge pipe and a large intercooler.

To give you an overview of the problem, when I first installed the sc kit, i took her for a blast around the block one day and did WOT from 1st to 2nd. When I did this it instantly developed this surging/hesitation issue. I assumed i'd blown the transmission. I saved up for ages to buy a RE4F04V (LSD auto variant). Once I received this transmission, I upgraded it with a shift kit (vb mod), new torque converter, brand new clutch packs, new seals etc and removed my old non lsd transmission.

I have received the car back and it STILL has this same surging issue.

I have spent ****loads on this car so far and I have come out empty.

Here are some pics of my ride configuration...

https://img130.imageshack.us/img130/3861/dsc0043l.jpg

https://img706.imageshack.us/img706/7366/dsc0044.jpg

https://img403.imageshack.us/img403/2687/dsc0045cd.jpg

https://img708.imageshack.us/img708/7044/dsc0046.jpg

I have thought maybe now it is an issue with the Vortech kit fuel pump as it has been making a strange whining noise recently. Does anyone know what is a good replacement module for this?

I have replaced the fuel filter, MAF sensor as well. The ECU is stock. Also the ECU is reporting 5-5 - no malfunction or codes.

The dyno results were a lot lower than I expected also... 236.55 hp @ 6100 rpm and 476ft-lb @ 5700 rpm.

Any help is much appreciated.

streetzlegend 12-04-2009 10:51 PM

Well most important question, have you logged your air/fuel? That can tell you a whole lot, and 90% of the time, issues like this are caused by electronics (tuning).

jordandalley 12-05-2009 02:40 AM

Hi streetzlegend - thanks for your response.

I have a log of my AFR and it's a little on the rich side but nothing to be too particularly alarmed about. Besides, I was running more boost with a stock ecu before and it didn't have this issue. I don't know why it's occuring, but I don't think it's tune related somehow...

t6378tp 12-05-2009 06:15 AM

what maf are you using and have you checked it

Nealoc187 12-05-2009 11:10 AM

What are you using to tune this car? I see no mention of that and that should be suspect number 1.

Also, those dyno numbers aren't right as you well know. It is impossible for your setup to put down 476wtq. That was either a typo or an issue with the dyno, like a torque converter flash or a downshift during the dyno run.

maxgtr2000 12-05-2009 01:41 PM

What about the mevi, is it operating correctly? I would guess if the solenoid was malfunctioning it could cause surging at wot. If you are running the stock maf you could be maxing it out if it's not the mevi problem.

jordandalley 12-05-2009 05:56 PM

Thanks guys..

t6378tp: I have ruled the MAF out. I replaced it and no difference.

Nealoc187: No tune yet. You really think this could be the issue??? It was running fine untuned before... I do have an emanage blue but it is disconnected at the moment while I find this issue. I have bypassed the MAF feed on the connector plug for the time being.

Does anyone have any example tune configurations for a similar setup to mine? I wouldn't mind checking it out.

maxgtr2000: The MEVI isn't activating. I disconnected all the vacuum stuff when I was trying to find the issue. Could the extra boost be making it activate by itself?

The surging feeling is on and off. It happens the worst at about 50 mph at WOT. It leaps off with a surge of power, then drops right off, then surges back in, then off etc etc. Bizarre as....

Just a question.. as you see in my first picture, I have a mini pod on my PCV valve breather. Could this cause issues? Usually it is connected to the intake path. I have seen other people run the same configuration, but just checking anyway....

jordandalley 12-05-2009 10:35 PM

Here's some dyno stuff for some food for thought.. yes the tune does look bad..

Dyno Graph
https://img46.imageshack.us/img46/2448/dsc0049g.jpg

O2 Readings
https://img137.imageshack.us/img137/6224/dsc0050v.jpg

Monifold Pressure (Boost)
https://img189.imageshack.us/img189/8476/dsc0051w.jpg

Injector Duty Cycle
https://img192.imageshack.us/img192/7033/dsc0052kr.jpg

Flava_24/7 12-06-2009 08:33 AM

So no wideband,no EMS, and your on stock injectors still?

jordandalley 12-06-2009 06:43 PM

Yep - correct. It's going in today. Will get the guys to give her a tune on the old emanage blue :)

Flava_24/7 12-06-2009 08:35 PM


Originally Posted by jordandalley (Post 7325086)
Yep - correct. It's going in today. Will get the guys to give her a tune on the old emanage blue :)

Definately sounds like its the tune. You really should get a wideband, that will help troubleshoot in the future.
Also, what plugs are you running and what are they gapped at?

jordandalley 12-06-2009 10:45 PM

It's back at the shop now. They're going to check it for the obvious boost leaks etc. They say they doubt its a fuel issue.

Plugs are the recommended maxima.org 2-step colder plugs. Coil packs tested fine also.

I know little of what a wideband o2 does. Is it an additional O2 sensor hooked up to an ecu or something? Is it like an auto tune or something or does it just give you a read out that you can manually tune by?

Do you have any resources to point me to in relation to this? Any recommendations as to which brand/model works best etc?

I know.. I should probably just use the search.... :P

Thanks for your help Flava :)

The Wizard 12-07-2009 11:13 AM


Originally Posted by jordandalley (Post 7325354)
It's back at the shop now. They're going to check it for the obvious boost leaks etc. They say they doubt its a fuel issue.

Plugs are the recommended maxima.org 2-step colder plugs. Coil packs tested fine also.

I know little of what a wideband o2 does. Is it an additional O2 sensor hooked up to an ecu or something? Is it like an auto tune or something or does it just give you a read out that you can manually tune by?

Do you have any resources to point me to in relation to this? Any recommendations as to which brand/model works best etc?

I know.. I should probably just use the search.... :P

Thanks for your help Flava :)

IMO, you should start with 1 step colder plugs first. More than likely, you'll never need 2 step colder plugs. You saw the formula for gapping the plugs correctly in the sticky, right?

A wideband O2 is an additional sensor installed after the ypipe legs meet and before the cat. It is not tied into the OEM ECU, it's your own independent way of monitoring your A/F. A complete wideband system will come with it's own "brains" so to speak. It gives you a readout you can tune by. You can also tie the wideband into an EMS and log your A/F. The EU can also do an "autotune" for you as a base, then the user should fine tune from there. I don't think the EB has this specific feature though. When not tuning, the wideband is a way for you to monitor what's going on as you cruise down the street, medium throttle, and WOT. Ideally, you want your A/F to be in the 11's during WOT.

Innovate Motorports, PLX, AEM....you have lots of wideband choices. I'm personally using the Innovate LC-1 with XD-16 gauge. Works great, and didn't cost an arm and a leg. $275 shipped I believe.

On a side note, get your MEVI to activate and work properly. You have several little issues that need to be addressed before everything can work together properly as a system.

I'll review your dyno graphs etc a little later when I have more time. :)

jordandalley 12-07-2009 02:02 PM

Cool - I was waiting for you to chime in Wizard. Good to see you again :)

Thanks for the advice. The MEVI was activating fine before. I just disconnected it for diagnostics. I had set it for 5,300 rpm.

Wideband O2 sounds like a good idea, and for $275 thats pretty cheap. Aussie dollar isn't far off the US dollar at the moment either which helps!

Gapping the plugs? This is news to me because I thought the NGK two steps came pre-gapped and required no modification.

I asked the guy at the shop if it were spark plugs, and he said something would have come up in the dyno if it was. I'm thinking about replacing them soon anyway - to the one-steps as you suggested.

Do you have any idea why my torque measures so high and my hp so low? It's a weird graph. Of course everything is in metric, so you'll need to convert the newton meters into foot pounds etc.. http://wiki.maximasdownunder.org/converter.htm

Will see what the shop says today :)

Flava_24/7 12-07-2009 08:09 PM


Originally Posted by jordandalley (Post 7326288)
Cool - I was waiting for you to chime in Wizard. Good to see you again :)

Thanks for the advice. The MEVI was activating fine before. I just disconnected it for diagnostics. I had set it for 5,300 rpm.

Wideband O2 sounds like a good idea, and for $275 thats pretty cheap. Aussie dollar isn't far off the US dollar at the moment either which helps!

Gapping the plugs? This is news to me because I thought the NGK two steps came pre-gapped and required no modification.

I asked the guy at the shop if it were spark plugs, and he said something would have come up in the dyno if it was. I'm thinking about replacing them soon anyway - to the one-steps as you suggested.

Do you have any idea why my torque measures so high and my hp so low? It's a weird graph. Of course everything is in metric, so you'll need to convert the newton meters into foot pounds etc.. http://wiki.maximasdownunder.org/converter.htm

Will see what the shop says today :)


The plugs are pregapped, but they are not gapped for a boost application.
If your running the stock gap, your most likely getting blowout.
5300 seems a bit high to have the MEVI open. Most of us have ours around 4700

jordandalley 12-07-2009 08:22 PM

Hmm... we did some dyno tests some years back on mevi activation points and this is what we found...

http://wiki.maximasdownunder.org/lib...aymay07ty7.jpg

Red line = 5300rpm MEVI

Blue line = 5500rpm MEVI

Green line = 4900rpm MEVI (Without exhaust upgrades)

jordandalley 12-10-2009 02:56 AM

You guys are onto it. Shop tested the Lambda on the dyno today. It's running so rich it's "off the scale". Basically it maxed their Lambda meter right out.

I have an emanage blue in the car and I hope that this will be able to sort my issues out. At the moment it's only configured to intercept the MAF signal and read the throttle position. I'll have the guys try and tune it tomorrow using the emanage support tool via a laptop on the dyno.

The guy at the shop is being quietly optimistic about the success of tuning it with the emanage. Basically he thinks the emanage is crap and the car needs a better ECU. I agree but for the mean time it's what i've got and money is short. Do you guys see any forseeable issues with tuning the car with the emanage blue? Guy at the shop thinks the tune is so far out that he is having doubt the emanage can correct it enough to bring it back into a good O2 reading... we'll see. What do you guys think???

Flava_24/7 12-10-2009 06:44 AM

Wow, I would have thought you would have been a bit lean, but with it being rich you should be able to pull fuel with the Emange Blue no problem.
When I first put in the 555cc inj they were dumping so much fuel that the plugs were completly saturated. I had to pull the fuse for the fuel pump and remove the plugs to blow out all the fuel. My Emange was able to pull enough fuel to start it up eventually, and then fine tuned with it.

accordingtou 12-10-2009 02:54 PM

I noticed you have an fmu which explains the surging once you see boost. I think the E blue will get you .82 (12.00afr) across the board & you should be fine.

jordandalley 12-10-2009 10:02 PM


Originally Posted by accordingtou (Post 7332266)
I noticed you have an fmu which explains the surging once you see boost. I think the E blue will get you .82 (12.00afr) across the board & you should be fine.

Yeah well the verdict is in. The guys at the dyno shop couldnt get the emanage to lean out enough. It's still running rich and apparently its made little difference.

Can I ask the question.. is there something wrong with my FMU??????? Can you adjust them in any way?

Cheers

PS. I am looking at a JWT ECU.. are these a good idea?

The Wizard 12-10-2009 10:15 PM


Originally Posted by jordandalley (Post 7332743)
Yeah well the verdict is in. The guys at the dyno shop couldnt get the emanage to lean out enough. It's still running rich and apparently its made little difference.

Can I ask the question.. is there something wrong with my FMU??????? Can you adjust them in any way?

Cheers

PS. I am looking at a JWT ECU.. are these a good idea?

Some food for thought. With the properly sized injectors, you can ditch the FMU all together. Standard FMU's are non-adjustable besides changing the disc inside. A Super FMU (SFMU) is adjustable though, but hella pricey and not worth it IMO.

Maybe I missed it, but what size injectors are you runnin?? What size disc is in your FMU?

JWT is ok if you like a cookie cutter tune. Can't maximize your cars potential, they take forever, and you'll have to send it to them every time you do a major mod. For that kind of $$, get an EMU and call it a day. Then add a little more $ for dyno tuning and your set.

Or, skip all the headaches and yank the EB, slap on a 3.125 pulley, keep your FMU with a 8:1 disc, stock injectors, and enjoy your Max w/o issues....just a little less power. :)

jordandalley 12-11-2009 02:46 AM

Hey Wizard. I'm still running stock injectors. I'm pretty sure the disc is the stock 8:1 vortech one. Got the car back though, and found the idiots at the dyno shop didnt use the software to tune the emanage - just the dials on the front :(

In relation to swapping the injectors, I have some Deaschwerk 555cc ones lying around somewhere. They're used, so I dont know how reliable they are.

Does anyone have any sample tunes I can take a look at? I'd be interested to see what they are like in comparison to mine. Mine is pulled way back to -20.

I bought a narrowband a/f gauge (yes I know they're ****, but money is short and at least it will give me somewhat of an idea - i'm not going to tune with it) which I'm still yet to hook up. I'm guessing I'm tapping the O2 sensor by the cat? I'm still trying to work out which wires are the right ones....

I have tried yanking the EB and even with the 3.125" pulley it was doing the same thing, so there's something strange in the works....

jordandalley 12-11-2009 05:47 PM

I found that the back bank O2 sensor harness was unplugged. Definitely not a good thing, though not sure if this would cause my car to run really rich.

maxgtr2000 12-11-2009 07:55 PM

The emanage without the injector and ignition harness is basically an safc/vafc so you are limited on what you can really do with it. Get those harnesses and the support tool and you will have something more usable. Don't waste money on a narrowband sensor, they sell Christmas tree lights cheaper at Walgreens cause that's basically what that gauge is. I would say the ecu is making the car run rich because of that unplugged o2. Once you get a wideband you will be able to see what's going on.

aic96max 12-12-2009 04:13 AM

not too sure how he car can be running super rich with stock injectors? was that a narrowband on the dyno? bc i have a scanmaster on my GN which uses similar narrowband numbers, and the higher the number the richer, the lower like .700s the leaner..that would make more sense.. with the useless shops you seem to be using, id go with use the stock ecu, w fmu, and a meth kit, and call it a day! oh and wideband is a must!

accordingtou 12-12-2009 02:45 PM

He has an fmu

aic96max 12-12-2009 06:32 PM


Originally Posted by accordingtou (Post 7334925)
He has an fmu

got it. dam, those things work well then, never used one myself, just injectors:rolleyes:

jordandalley 12-12-2009 09:36 PM

yeah... you guys are right. narrowband o2 gauges are crap! I'm taking it back for a refund.

jordandalley 12-13-2009 02:57 AM

Well, at least now the O2 sensor is plugged back in.

I've pulled the emanage out and now its just running a stock map.

So here's what we have...

Stock MAF, Stock ECU, 10.5 psi boost, 8:1 FMU Disc and Vortech T-Rex fuel pump.

Unfortunately, it's still running too rich and is surging - especially noticeable in 2nd gear.

I'm really at a loss.. something is wrong and I can't put my finger on it.

The thing is, it used to work fine - now it's got some issues. I'm still thinking its that FMU playing up, but i'm not too sure.

If I took some pictures of my setup, would any of you be able to tell me if I have anything hooked up incorrectly?

jordandalley 12-13-2009 04:27 AM

OK, I fixed it!!!!!!!

I was ready to pull my hair out. I was right, it was the FMU.

I pulled it apart and the disc wasn't sitting dead centre on the piston.

On top of this, the piston wouldn't move and was jammed in there. There was some debri and dirt around it so I cleaned it all up and sprayed her up with some WD40.

Put her all back together and took the car for a spin.

Smokes first gear now - goes like a rocket like it used to!

The gaskets were a bit poor - does anyone know where I can get replacement ones?

Now I guess it's back off to the dyno :)

Thanks for your help everyone :)

wirelessdude04 12-13-2009 10:10 AM

glad you fixed it bro.. But def get a wideband as mentioned before... Def needed in any boost application

jordandalley 12-13-2009 01:42 PM

I definitely will man. It'll be my next thing :)

Nealoc187 12-14-2009 10:18 AM

Glad to hear you got it fixed, told you it was a tuning issue :D

Emanage Blue is a perfectly good tuning tool, those guys at the shop just apparently don't know how to use it as it is intended to be used, or just neglected to use it that way. Ultimately you'd do best to get those larger injectors installed and ditch the FMU as the FMU will cause you to run extremely high fuel pressure and duty cycles on stock injectors which can lead to premature injector failure which will blow your motor. Larger injectors and moderate fuel pressure with a proper tune (both AFR and timing) is the way to do it.

jordandalley 12-14-2009 07:31 PM

thanks for the info. Might be time to put those 555cc injectors in and then figure out how to remove the FMU.

Just a question - if the car has 555cc injectors, then do I remove the vortech fmu and pump? They seem to be connected together. So, does this mean that I just return the fuel system back to stock configuration?

The Wizard 12-14-2009 10:31 PM


Originally Posted by jordandalley (Post 7337640)
thanks for the info. Might be time to put those 555cc injectors in and then figure out how to remove the FMU.

Just a question - if the car has 555cc injectors, then do I remove the vortech fmu and pump? They seem to be connected together. So, does this mean that I just return the fuel system back to stock configuration?

With the 555's, you'll remove the FMU and return your fuel setup to OEM spec and keep the T-rex fuel pump in-line. Very simple to do. :)

jordandalley 12-18-2009 04:42 AM


Originally Posted by The Wizard (Post 7337831)
With the 555's, you'll remove the FMU and return your fuel setup to OEM spec and keep the T-rex fuel pump in-line. Very simple to do. :)

That's if I can remember how to return it to stock.

Might be a little project I can do over christmas :)

jordandalley 12-20-2009 02:19 PM

Still seems to be running quite rich. I have put a bigger muffler on the car and I can hear it backfiring at WOT. Reassembly of the FMU seems to have made it better, but it still carries on a bit.

I can't get over the fact that the disc sits on top of the piston (shown below) and the gasket sits on top. There isn't anything holding the disc in position. Is this normal? This kit was second hand, so I have no idea if it's meant to be that way.

https://img710.imageshack.us/img710/4245/discc.jpg

Also, the gaskets are shot. I have ordered a recon kit from Capa (local vortech supplier) to fix this.

The lower gasket likes to bubble up - i'm sure this doesn't help.

https://img706.imageshack.us/img706/2111/gasket.jpg

I still need to get my 555cc injectors tested to see if they work before putting them in. After this I guess the FMU wont matter :P

jordandalley 12-24-2009 02:23 AM

Ok.. I'm about to tear my hair out.

I have received the minor repair kit from vortech (which is an upper and lower gasket, new lower aluminum disc, and lower o-ring seal). I installed it this afternoon and the car is back to backfiring and surging at WOT. WTF??!?!?!

I'm convinced there is a problem somewhere in the fuel system.

As mentioned in my previous post - is the upper washer supposed to just sit on top of the centre piston like that? Seriously?

I have checked all my vac lines as well. I am tapping the vacuum source from the smaller nipple on the back of the manifold behind the throttle body. It tee's off to the BOV, stock FPR, FMU and the fuel pressure switch. I assume this is correct?

There is a larger nipple which feeds into a large vac can mounted to the firewall. This then feeds back up to something - i dont know what, next to where some of the fuel lines go through. I assume this is OK? I'm unsure what that big vac can is for.

At idle, vac measures at just shy of 20 in hg.

As mentioned previously.. it might just be time to ditch the FMU and go for the bigger injectors, but i'm really tight for cash at the moment and keen to get it running ok.

jordandalley 01-04-2010 02:08 AM

Talked to Vortech today. Guy on the phone recommended I go to a 4:1 disc for the FMU if my current 8:1 disc is too rich.

Is a 4:1 disc ok for this? It won't be too lean will it? In my calculations it would drop fuel pressure from 97 psi to 57 psi if i'm boosting 10 psi. Thats quite a lot....

The Wizard 01-06-2010 04:10 PM


Originally Posted by jordandalley (Post 7363089)
Talked to Vortech today. Guy on the phone recommended I go to a 4:1 disc for the FMU if my current 8:1 disc is too rich.

Is a 4:1 disc ok for this? It won't be too lean will it? In my calculations it would drop fuel pressure from 97 psi to 57 psi if i'm boosting 10 psi. Thats quite a lot....

57psi of fuel pressure is a good thing. 4:1 just might do the trick. You could always buy the full recalibration kit with all the sizes in it for a few bucks more, so you have the 6:1 disc too.

I'd also make sure the FMU internals are installed correctly. From what you're saying lately, I think you might have installed your rebuild kit incorrectly. I can pull my old FMU apart and shoot a pic if it would help put your mind at ease.


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