Bad tuning or knock sensor? tach bouncing at 6,200 RPM's

[EfiniX]

543/1000
Lot's of a/m parts. Got it for a song because the last owner decided to buy a completed project. Big turbo, intake, exhaust, fuel pump, injectors, etc etc etc.

I know the ECU has been tweaked. What I don't get is why, when I pushed it this morning, it bounced the RPM's when it got around 6,200 RPM's. The thing runs and idle's perfect and even smogged at DEQ yesterday with flying colors. Now I'm not familiar enough with GVR4's to know what happens when there's engine knock. I do know the last owner told me that he could never run more then 13PSI because it would cause knock.

It felt like a rev limiter. No check engine or warning lights and no odd sounds (aside from the engine RPM's bouncing off of whatever it was). Same in 1st, 2nd, 3rd. Stopped pushing at that point.

I'm ready to buy an ETS intercooler and DSMLink. I was going to put it off, make it a reward for passing a certification exam, but if this is knock, I'll pull the trigger on it now.

Of course, if this behavior is NOT what the knock sensor would do in the cases of severe knock (where it can't just retard the timing a bit), then my guess is the last guy had the tuner set the rev limiter lower then the redline for some reason and I'll get this bitch out to English Racing and get it sorted out.

Thanks in advance, guys!

C

 

[quato]

it probably has a keydiver chip in it or something similar. there are instructions on dsmchips.com that you can follow for the clutch wire mod. sounds like the wire is loose

 

[EfiniX]

I'll check. thanks and if anyone else has any ideas, please let me know.

 

[quato]

actually it might be hooked up to the wrong clutch switch...i would check that first. if it's keydiver it should be connected to the lower switch

 

[EfiniX]

My guess wiring issue. Old owner said it worked fine before and it would explain the random purple wire hanging over by the hood release. Gotta adjust the clutch this weekend, so ill see then.

 

[desant78]

How are you supporting these mods that you made/have? The ECU must be chipped for all this aftermarket parts to work in the car. I would go through the car, and figure out the mods best I can. For example, an upgraded fuel pump will be very important.

For your problem, finding out what you did ECU/tuning wise will point you in the right direction, and might be the most important piece of your puzzle.

Here is what I'm going through right now

click

Good luck!

 

[LIV4PSI]

Fuel cut due to knock feels like hitting a brick hall. Everything feels great, than BAM! That doesn't sound like what you are explaining.

What kind of intercooler does your car have now?

Pull the ECU and see if it has a chip?

Post a mod list or pics so we can tell you whats done.

 

[EfiniX]

I verified with the previous owner's mechanic that it does, in fact, have a keydiver chip and he doesn't remember if they wired the clutch or not. Definitely the right place to start. As far as mods, here you go (and I still building the list as I find stuff).

stock intercooler (this will go soon in lieu of an ETS module and DSMLink)
20g turbo
1000cc injectors
255 walbro fuel pump
kevlar timing belt
full rebuild @ 95k miles 0.5 overbore/forged pistons/forged piston rods
balance shaft removed
Hallman manual boost controller
Fujitsubo Legalis R Complete Cat-Back, 76.3mm pipe with 102 mm tip - 140296
K Sport coilovers
2g ported manifold
2.5" custom fab downpipe

And, strangest of all, there may be HKS 275 cams installed, but no one is sure. I'll be checking this weekend.

There are other little odds and ends, but that's the basic list. I keep finding stuff, even with all of the paperwork.

C

 

[LIV4PSI]

Stock intercooler and a 20g /ubbthreads/images/graemlins/banghead.gif

I would avoid boost for now

 

[EfiniX]

LOL, well yeah, that goes without saying. It's cut at 13psi. no knock and I don't push it hard. ETS in the future. Just got the car last weekend and I'm still sorting through the mods!

As far as this issue goes, I did confirm that a keydiver is in use. A quick look under the dash by the clutch pedal...



Maybe found the problem, eh?

 

[quato]

it looks like that wire cut is going to the upper switch? the keydiver uses the lower switch so check that...i believe Link uses the upper switch. more knowledgeable people please correct me if i am wrong.

 

[LIV4PSI]

Quoting EfiniX:
LOL, well yeah, that goes without saying. It's cut at 13psi. no knock



How do you know there isn't any knock? Unless you have a working logger, you don't.

I don't think you can 13psi on a 16g without there being detonation.

 

[DynastyLCD]

Quoting quato:
it looks like that wire cut is going to the upper switch? the keydiver uses the lower switch so check that...i believe Link uses the upper switch. more knowledgeable people please correct me if i am wrong.



you can use either switch with the invert signal option, if yours was wired one way or another

 

[EfiniX]

I believe it's the lower switch, just looks like the upper because it's upside down and the plug is actually ziptied to a wire in the foreground (so not even close to where it actually plugs in).

I also wanted to share my reply to LIV4PSI here so if there is more feedback, I can get it from the community!

vvvvvvv

You make good points. I haven't seen any codes, but I suppose that isn't a smoking gun either. My comment was/is based on two things, although you have much more knowledge, so I would certainly want your opinion (not trying to be contrarian. If I'm nuts, tell me!)

Andre with Pima Motorsports programed the keydiver chip and tuned it. Even told the last owner he wouldn't go above 13PSI without an intercooler because he was afraid it would blow the motor.

So that, but hey, he could be wrong or conditions he based his comments on could have changed since he made them. I trust him, so that goes a long way.

Second, my understanding of the keydiver chip is that it converts the stock boost gauge into a real-time knock sensor. From the keydiver FAQ:

***
The knock gauge mod converts the useless factory boost gauge into a gauge that registers the ECU Knocksum, a value from 0-43 that corresponds with how loud and how long in duration the ECU hears knocking from the knock sensor. Not only can the knock destroy your engine, but for every 3 knocksum the ECU will pull almost 1* of timing advance, killing your power. You really don't want to see more than 1-2 knock on the guage.

GVR-4: Each LED on the knock gauge is 5 knocksum.
***

I haven't seen any yellow on the boost gauge and I haven't felt any noticeable power cuts that might be timing retardation, so I'm thinking I'm ok.

Thoughts? and please, I'm planning on putting off my intercooler and DSMLink until I pass an exam I've been studying for (kind of a reward), but if I need to get my butt up to English Racing like yesterday, I will

 

[LIV4PSI]

Here are what I believe to be the important key notes.

1. Your car has been improperly modded, and therefore isn't running right.
2. According to RRE, the intercooler needs upgraded before running more boost on even the 14b.
3. It sounds like fuel cut, which occurs due to knock.

Chipped ECUs are generic tunes. They are made to work on all cars with the same setup. There are inherent problems with this. My guess is either it is hitting fuel cut due to the fall/winter air being more dense. Or your car has boost creep from trying to run 13psi on an internally gated 20g, which is no where near its efficiency range. Also, are you sure its only running 13psi? I didn't see a boost gauge listed.

If you want to wait for a FMIC and ECMlink, that's fine. Just stay out of boost until then, or be ready to possibly fix an engine due to detonation.

 

[EfiniX]

First off, thank you very much again for your response.

Well aside from the cut, it seems to be running fine. Smogged with flying colors. Starts/runs/drives just dandy with smooth power and no sluggishness. Andre at PINA motorsports did the bulk of the work (including the ECU stuff) and I'm to understand he's in good standing in this community, so I can't speak to the "improperly modded" piece. I would certainly agree that it was a project left unfinished, but so far as I can tell, a proper programmable ECU and intercooler are all that's left.

Yes, I do have a boost gauge and can confirm my boost numbers. I read through the Road Race Engineering (I assume that what you meant by RRE) FAQ on upgrading Galants and I didn't come across any mention of boost-to-intercooler ratios.

click

Now that being said, I understand that any substantial increase in boost will require an intercooler, so I don't plan on touching the BC. I'll leave that to English Racing when we do an FMIC and DSMLink. I did find some talk on the RRE FAQ about the need to flow more fuel for anything higher then 15-16psi on 92 pump gas. I have a 255 Walbro and 1000cc injectors, so I"m pretty sure I'm ok there.

If the boost-to-intercooler discussion is elsewhere, I would love to read it! Again, I'm not trying to be contrairian and my main focus here to ensure the health and long-life of my car (thus, not driving it until I get the keydiver clutchwire mod fixed at least).

And finally, can you tell me more about the fuel cut due to knocking? All the reading that I have done on the topic so far has suggested that when your ECU detects knocking, it will retard the timing. Thus the most obvious symptom to a driver of a car with knock is a sudden, laggy loss of power. I haven't heard anyone remark that the knock protection manifests like a rev limiter or stutter box. Just that your car will get laggy, like it has fallen flat on its face. This is not happening in any gear at any RPM. I just get a rev-limit at 6000rpm's.

 

[LIV4PSI]

RRE has a suggested upgrade path for GVR4s. The intercooler and piping is suggested BEFORE a manual boost controller. Therefore, they are saying that before you even consider more boost on the stock turbo, the horrible OEM intercooler needs be addressed.

Andre at Pina is very well respected and I would gladly trust him with my car. With that being said, he gets paid to do what the customer wants and can only give his advice. Whether the customer listens or not is a different story. I guarantee that he doesn't suggest running a 20g on a stock intercooler setup. Running a larger turbo without proper supporting mods isn't the proper way to modify a car. You already realize this, that is why you completing the setup properly. I guess "unfinished" may have been better wording than "improper." Either way, it is a poor setup as is.

As for knock, or detonation, it can happen extremely fast. You are correct in your understanding that the ECU will pull timing if it detects small knock counts. But, the ECU is only able to pull so much timing, and after that point it hits fuel cut as a safeguard. Think about your situation. At higher RPMS, everything is working harder, the turbo and engine are both spinning faster, and that 20g is fully spooled and meant to be running 20psi or so. The pressurized air is not only hotter (more need for a real FMIC) but the interal wastegate is struggling to keep the boost at 13psi.

I can't guarantee that your car is hitting fuel cut. But I can guarantee that fuel cut happens due to high knock and it is usually in the higher RPMS. And the car will run fine when its not in boost, at lower RPMs, and sometimes even until redline in the lower gears.

Be safe and be easy on it until you get your setup finished. Anything less is an unnecessary risk.

 

[EfiniX]

Excellent analysis and excellent advice. I'll fix up the things I can and keep the car in light-duty for the time being until I can get it up to Lucas at English Racing!

C