2500+ RPM, clutch in, car dies...Alternator?

[broxma]

Best I can figure anyway. Thoughts.

I have tested the ISC, used 2 throttle bodies that both tested fine. This has happened on both my chipped ECU and the Evo ECU that is now in the car. I can't think of any other physical reason why the car would do this other than the alternator. I have no boost leak, the brake booster valve isn't in backwards. I have capped off every possible hose and widget in an attempt to find the source of this condition and nothing has made a change. My last supposition is my Braille 11.5 doesn't have the moxie to kick in reserve juice off throttle and the alternator, probably original for all I know, is not up to task. I have noticed fading lights and small variances in voltage during high demand times. My front lights dim when I crank the radio FFS so I am leaning towards Alt.

Anyone got any data to support this claim before I yank it out to get tested?

/brox

 

[TurboTrader]

I've had two alternators die in my Galant until I wised up and went with a used OEM unit, so far so good. Could be your issue, or some of it. With a voltmeter hooked up and a rev, you can easily tell if your voltage is dropping or steadily rising. Even with a good battery and a bad alternator, the battery should be able to supply the necessary voltage.

I would check is the fuel filter, if it is clogged, little fuel will be supplied on demand.

 

[broxma]

Filter is a brand new Trick flow unit on my fresh build. I opened it up a few days ago and it's clean as a honeypot. I pulled the injectors, even though I knew they were good, replaced those. Car starts up instantly except it does on occasion hang and I have to kick the ignition over a few times. The Braille battery I have has been almost drained dead before but I have charged it back into life, but the alternator is the one that came with the car. I'm more curious if an electrical issue could be the culprit considering I have ruled out almost every other physical issue I can think of.

/brox

 

[cheekychimp]

If you have the car in neutral rev to 2500 rpms and push in the clutch does it still die?

 

[broxma]

It will at times. Occasionally, even just at an idle, reving the motor will cause it fall out even if the idle was fine(950 or so) right before. Oddly it seems to get worse as the car heats up. It usually is controllable by allowing the RPM's to fall during decel in second, to about 1.2K, then I push in the clutch and it will be relatively ok. When it's hot, even a slow decel and it will try to die. The alternator argument I make is mainly due to the fact that it is one of the only parts from the original car I have left and I am unsure of it's abilities. The alternator is relocated to the rear with a Jay Racing kit. Wires are soldered and oversized.

I have cleaned, tested and checked every part widget and valve I can think of. I have one last item I am going to inspect tonight before I rip the alternator off tomorrow.

/brox

 

Clutch switch?

 

[cheekychimp]

Quoting broxma:
It will at times. Occasionally, even just at an idle, revving the motor will cause it fall out even if the idle was fine(950 or so) right before.



There was an EVO IV in the shop quite a few years ago, that did exactly that, but everytime. Started and idled fine, push the clutch in and it just died. In his case it was worn bearings at the clutch/crankshaft that resulted in movement at the crankshaft everytime the clutch was pushed in. If you are sure your TOB and crankshaft thrust bearings are okay, not your issue, but worth a look if not!

 

[broxma]

Every item inside the motor other than the head casting and block itself is brand new. Clutch is new, TOB new. For background on the car, it's new. If you ask me about pretty much any part on the car, new. Except the alternator. I am trying to understand how the alternator would be the root cause of this mechanically. Regardless, it's Sunday so I'm going to pull it today and check on a replacement if it tests bad.

/brox

 

[cheekychimp]

Okay work with me on this, I'm having difficulty seeing how the alternator is related to this. I've driven a VR4 with a dead alternator before. The headlights dim, the dash becomes progressively dimmer, and yes it does eventually stall and die but it either had the juice to run regardless of whether the clutch was engaged or not or it didn't work either way.

I don't want to dissuade you from checking this piece of the puzzle but why not charge up the battery, disconnect the alternator and see if the problem persists? If it doesn't, then reconnect the alternator start the car then disconnect the battery. If it is the alternator you should see some results BEFORE you actually pull the whole thing off. Hell park another car there and run jump leads across and start the car and see if it still does it.

 

Do the revs drop if you press the clutch while idling?

 

[broxma]

No. It's not a clutch issue. I mention the clutch only to represent the uncontrolled drop in RPM from being on throttle to off. Ignore the clutch. The issue stems from no other system in the car being out of ordinary, every critical component replaced, nothing left to chance. That is why I am leaning towards an electrical issue. My hypothesis is that the alternator, when at idle, able to maintain voltage with help from the battery. When the rpm's drop, the alternator makes less and less usable voltage. This begins a cascade effect of voltage issues, be it at the IAC, Injectors or otherwise. Voltage is the only correlation I have thus made to the stalling condition. Every other aspect of the car is functioning normally, until the voltage drops coming off throttle.

I'll find out tonight. I'm building a door right now and not in the garage mode as of yet.

/brox

 

Your small battery/failing alternator suggestion seems reasonable, but doesn't seem to explain all the behavior you've described.

From what you're saying, it dies when coming off the throttle if the engine is warmed up, and sometimes when at idle and the throttle is opened. However, it runs fine when on the throttle, or when decelerating while leaving the clutch engaged down to below ~1.2k RPM (most of the time). The last part is what makes me think it's something besides just a bad alternator. /ubbthreads/images/graemlins/dunno.gif The alternator seems to work predictably, if intermittently, if it really is the component at fault.

Is your battery discharged after driving the car? In any case, I'm interested to see what this problem is.

 

[cheekychimp]

Quoting broxma:
No. It's not a clutch issue. I mention the clutch only to represent the uncontrolled drop in RPM from being on throttle to off. Ignore the clutch. The issue stems from no other system in the car being out of ordinary, every critical component replaced, nothing left to chance. That is why I am leaning towards an electrical issue.
/brox



I'm with the previous poster in that what you are advocating is logical but I'm not convinced it is the sole issue. Given the fact that you are convinced it is not clutch related, what you are describing is similar to a situation where people vent their BOV to atmosphere and the engine stalls or dies coming to a stop ... correct?

I'm going to assume you aren't venting to atmosphere. It does not sound like the sort of thing you would do and would inevitably result in one or all of us having to "kill you in the face!"

So what does that leave? Properly operating/grounded throttle closed idle switch? Correctly set TPS? Are you running a stroker or larger displacement 2.4 litre? Are you running a fluidampr pulley?

Also I really am not trying to be a dick by saying this, I am just trying to help diagnose here and that means after exploring the expected and the obvious you have to start considering the unexpected and not so obvious. So the fact that a component is new does not necessarily preclude it from being bad.

If it is the alternator though, I definitely want to know.

Paul.

 

[broxma]

Since today was build a secret door into my upstairs loft day and the wife was all uppity, I did not get out into the garage. Tomorrow I am only spending time to figure out the issue. Will update.

/brox

 

[solidviper89]

Any updates? When are you making a trip to the junkyard?

 

[broxma]

Yes. Update is that in fact I did have the BOV venting due to the odd intake configuration. However, I reset the ECU, recirced the BOV to the intake and nothing changed. Tomorrow I am going up to the shop to get some modifications made to my IC pipes with a new location for the BOV. I don't think the IC core is ready yet but I'm going to get started with it. When I am up there, I'll get their equipment out to look at the alternator. I have been monitoring voltages off throttle and it appears voltage is dropping lower than I would expect before the car comes to idle RPM. Example. At idle, I may sit at say 13.5, just an example. Off throttle, the voltage will be at 12 as the car winds down after I press in the clutch even though it is in transition from say 4K-1K RPM wise. It seems as though I have some loss of voltage during decel under no load. at 1K rpm or so, I have seen voltages as low as 9.

It seems when demand is highest, the alternator is petering out. Again, still looking into it.

/brox

 

[524of1000]

Damn. I wanted to be right this time lol

 

[broxma]

You're always right sweetheart. BTW your springs/retainers will be here next week. the guy has the head at the shop still but he'll update soon as they are out.

/brox

 

[broxma]

So today we got at the root of the problem. The alternator was in fact fine. The problem was user error or in this case installer error. The main power wire I ran for the positive off the alternator was actually a twisted triple wire. 2 of the wires had somehow not managed to stay in place after the last install and the solder joint had essentially broken. This meant power for the car was being fed through a single 14 ga. wire. I pulled the wire, reattached it with the better shop equipment and all was right with the world.

We consequently started working on the plan for the IC pipes since we had sometime. I have plotted a solution for the new turbo and the intercooler. I may be using a 3.5 inch core however instead of the planned for 4.5". We have access to a lot more 3.5" core than 4.5 since it is more common.

The resolution center has reviewed the stalling issue and concluded it was amperage related. Seems the draw of the parts was too much for the single wire to allow for. I suspect this may have actually been related to my weak motor mount issue which I am addressing right now.

/brox