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Posted

Is it possible, that the TPS, at idle rest; has the "wiper arm" on the variable resistor right at the end of it's travel. It would be better, to have the pedal at rest indicate a minimal output, & recalibrate the TPS in the ECU software,   Alternatively, without the engine running; disconnect the TPS, & hook it's output across a multimeter, reading ohms. Then watch the meter as you slowly depress the throttle pedal. If the resistance does not change, the instant, the pedal is depressed slightly, then recalibrating is required. 

Cheers Banjo 

Posted

Yes, the stock ECU method of setting up the TPS is to have the throttle plate at idle with a set of feeler gauge under the stop and then rotate the TPS until just before it give a reading on a multimeter. That way the stock ECU has the 4th wire idle switch to tell it the motor is idling, and the moving TPS starts reading as soon as the plate turns.

The Haltech only needs 3 wires, they don't measure the idle position separately, so you just enter a voltage that it treats as idle. Like you say, I've tried setting the 'idle' voltage higher and lower than it reads at idle, usually about 0.06volts.

Posted

So, one of my two tack-welds that temporarily held on the tailpipe broke from the vibration after many months of being temporary. Seeing I was at home I just put a screw through the side of both pipes. Last week I had it on the hoist changing oil at the workshop and Josh volunteered to 'fix the tail pipe'.  So it received a larger diameter stainless piece of pipe...  and its noisier again! Somehow it vibrates through the car at low rpm, so around town everywhere.

This is why car companies pay engineers so much!

  • 2 months later...
Posted

This happened last month-

IMG_8800.thumb.JPG.e914b08150e832a423e3775eb5a99649.JPG

Other than that... more tuning, I cut the 2-10% columns out of the fuel map, thinking the ECU can just work out what it needs to be without so much micromanagement. I think it makes the fuel mix more variable, looking on the wide-band. It settles down in a steady state but can read rich or lean initially after throttle movement.

When I get some time I'll change the dizzy to the one that Banjo built, and fit the COPs, just to see what differences that brings.

 

Posted (edited)

Hmmm !  

image.png.e893aa7dc0b9571b8aa2adf391ba26ba.png

Does your setup, include a idle control valve, & is it being used ?  When the engine is warmed up & idling; is the idling nice & steady ?  The changeover of the ECU from idling to higher revs, seems to be where your issues appear. (as soon as you touch the throttle, & the TPS comes into play). I suspect that the O2 sensor output is probably not even used; in the idling control programming ?  It may well be, that the older Haltech E6 series ECU You are using, is a bit too slow, at this point of the program.   Have you recalibrated the TPS, recently ?   Long while, since I used my olde Haltech EK6, so I cannot member any idiocies, I may have come across with it.  It would do well, to put the timing light on the engine, & just see if there is anything unusual appearing to happen with the timing, at the point, where you, commence the throttle movement, when taking off from a standing start.  There is an answer; so it is just a case of "seek & find", methinks !   

Cheers Banjo 

Edited by Banjo
Posted

No, no IAC on 4AGEs, just the air bleed screw. So a combination of air bleed volume, fuel supply when cold and ignition timing to stop it running away when warm.

Having ground cams makes a smooth idle unlikely, and idle injection timing has an effect there.

Wiping out the cells below 10% has smoothed it over, and dropping the 'pump jet' and zero-fuel over run completely has also helped. Now you can sit in one cell at 100kph and change throttle for a slight hill, up or down, and the mixture changes anywhere from low 14s to mid-15s without it moving out of that cell.  After all, there is 9% throttle in that one cell, and cruise at 100kph is only 6%.

The pump jet, otherwise known as extra injection under some conditions, was probably the culprit for the power hitting too hard after a tenth of a second delay. The motor saw a lean mixture as the throttle opened slightly, then a rich mixture straight away after. The bang of acceleration was giving the gearbox and diff a hard time, probably exacerbated by the very light flywheel.

The zero injection on over-run meant no fuel at all until the revs dropped to a set speed, say 1500rpm for an idle of 1100. So the motor would be lean at 2000rpm as I slowed from 100kph to 60, then as I eased on the throttle it went from no fuel to too much fuel instantly.

So those changes have smoothed the clang as the power hits, made it easier to drive away when cold, and maybe reduced the jerking as throttle is applied, but the next factor will be to see what its done to fuel consumption over a couple of tanks.

The idle is fine, cold or hot, its like any car with cams, but the cam grumpiness is what shakes the car when a  touch of throttle is applied. TPS gets calibrated every month or two, it moves off zero now and then. I've run it with 'zero' both below the idle voltage, and above so it doesn't reach idle at different times.

I can watch the advance on the laptop on the passengers seat, and record it on a drive. It jumps up and down alongside the rpm when the car jerks, but I'm not worrying about that anymore until after I change dizzys.

 

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