I've been noticing a severe hesitation (akin to fuel cut for a split second) @ *exactly* 2000 rpm. My TPS is ok, my o2 is ok, all 6 injectors are beautifully spraying as they should... but I'm still getting this nasty miss. It's not with a certain throttle position at all either.

I notice it mainly going up a good hill in 4th gear (no lugging, just... moving). If it's at 1500 and i gas it, seriously... right at 2k rpms it hesitates and once it's past, everything is good. no change in engine tone at all.

any ideas? could this be a MAF crapping out?

 

i have a spare maf if you want to test

 

 

probably the MAF is loose. I had the same problem

 

I bet its just the lack of VE Powah!





oh, you just have to find the MAF btw

 

@ *exactly* 2000 rpm:

If you take MAF connector out, at that rpm ECU-safe mode cuts it off. Points to MAF ...or ECU/MAF relationship...

Have you ever cleaned the ECU/tranny computer connector pins? Use white carboard to clean both side pins.

 

i've never cleaned the connectors before... one would think it's a lifetime connection!

I'll try them, i guess

 

Its a computer... Std. computers have such problems 'once a year' [not speaking of PC's but mainframes], ...plus this is in hostile environment.

The problem with the whole idea of computers in cars, is the idiotic signal level: few volts. Even minor Oxidation can kill that signal! You'll understand why they use rubber seal military specs -connectors...

100% sure you'll get your white cardboard black from one pin... Nothing else should be used as they are most probably golden plated with few microns. Never scrape, never use any solvent, ...Might use electric cleaner if you suspect that u cannot reach. If u use it, use liberally...Next hop to electronic s hop.

Also electric freezer is good at troubleshooting (oxidation) as cold conducts electrons better and contract all things.

Temporary help is just to open and close connectors. Btw. Do clean all connectors you have in u car, put tiny bit contact grease in every connector pin under the hood...

 

Where can I get this white cardboard? I opened up my TPS connector and it had some green dust in it. How should I clean it?

 

"green dust" indicates corrosion. who knows how far that corrosion goes into the sensor unit... you might as well get a new one as far as i'm concerned.

 

ECU:
Use white cardboard only to ECU pins. World is full of packaging, cut some... do not use the glossy one. White paper is ok, but hard to fit anywhere...

The white cardboard/paper contains caolin about 50%. That is actually 'stone'... This is fit to hone the pins clean.

TPS:
More probably its contact grease, as those connectors are military specs with a rubber sealing...

Clean with electrical cleaner, dry, add contact grease very tiny small bit...

 

I just thought about this....

If it was a corroded contact on the ECU pins that require "cleaning" my problem would not be @ exactly 2000 rpm. They would be everywhere....

I checked it out and it was not my MAF... not my TPS, and most definitley NOT my ECU pins.

Cookie to the correct guess.

 

ECU jumps to safe mode [2000rpm limit] for few reasons. One of them is loss of MAF signal. If MAF circ has not good contact somewhere, it will play games with ECU.

ECU pins do not have corrosion, absolutely. But. Keep any connector in a car ten yrs and each pin [100%sure] will become to have some oxidation, metallic electronic level relocation, absolutely. This results in higher resistance, does not ask anybody...

As ECU is a analog/digital computer, its analog inputs dedicate what logical states the register will store. This dictates what the programmed output will be. That process [based on rnd resitances in analog inputs] is a thing which no human can guess right, only heaven knows.

Is this a problem now in any car over 10 years, absolutely. Is this as big that you can 'feel' it, most probably not. Is this u 2000rpm problem, who knows - you dont, I dont.

But just do not clean the ECU contact oxidation [seen in blackened cardboard], cause theres a cookiedanger that your car would start to behave like dream...

 

I tell you.. if your MAF is bad, lot worse tricks would be played on u by the ECU. it didn't only cut fuel for a second or 2, it did for 15 seconds and at ANY rpm.. and it stalled, and it engaged safe mode for many KMs in one trip, and it was really hard to start after ur ECU cuts off ur fuel while u're running.. and that sucked!
i've been driving like that for 3 months until i got another MAF to fix the problem last week.

and ur ECU would have code 12 stored if the MAF is bad or its connection was lose. so check error codes.
otherwise it might be vacume leak, but this one is just my guess..

 

if

...if=true, ducks drive overboard engines...

ECU store errors that it has been programmed to, no magic in there. Analog inputs have predetermined trip levels, rise times, windows...etc. Everything in inputs that has not preprogrammed will not ever show up the right way.
Calculating ECU inputs and possible combinations will give a mathematician a nice number. Will fifty error code palette explain all those? Gimme a break...

Sometimes, as Microsoft stocks are up, stars aligned, full moon, wind NE, supply voltage up at ECU AND CLEAN CONTACTs ALL OVER: ECU gives the right answer for a given problem!

 

design flaw in the engine

it is when the belts stretch from the interia of the crank goes too fast for the valvetrain. The hesitation is the valvetrain becoming retarded.

you can fix it by getting one of those motors with a double roller chain under the timing cover


no seriously, no ve no care

 

shens and bullshiets. Kevlar timing belts dont stretch. oh, i can shoot at it too.... BULLETPROOF NUKKA

edit: cookie to maxnub91. I have a vacuum leak that opens at 2k rpm. PCV hose to valve. @ 2k rpm, i hear it suck in, engine stutters, then revs.

 

your not alone my ve seems to have developed the same issue....at about 2K rpm she studders then unleashes at WOT.....plus its sluggish when it gets warm and the valves are tapping.....NOT ITS NOT VTC

 

oh, you mean the one that was cracked when we did the valve cover job?

 

Just one thought:
One warmup variable at low rpm is the idle air bypass valve, 'warmup' controlled by engine water temp, last 'assy' in the IACV 'pack'. Theres the gas filled actuator controlling this air bypass valve. If it has jammed or cooling liquid circ poor to that device, surely results in hesitation from idle accel.