first off the biggie, I'v suffereing for terrible suttering when both driving (change gear and when you re-apply the throttle it stutters) and when my car is idling (blip the throttle and the engine stutters then picks up).

Is this related to how I've connected my injectors? I've got 1 & 3 attached to the 1st inj output on the MS and 2 & 4 connected to the 2nd output. I did this but cutting the loom my the stock ECU and using a connector that allows 2 into 1. I refuse to believe it's bad setup as I've been sent 2 known good MSQ's and I've faffed about with AE for hours this past week to no apparant success.

Second (may relate to the 1st) I've not yet connected up my Idle, i've added a TIP122 as per the MM, not i notice that Aussie said he fitted D?!? (I forget which diode) accross the wires on the Idle solenoid. My question is, which way around?

Thirdly, i've not connected up my TPS either (also related to the 1st problem?) I've got 2 wires from the MS and I can only find 1 wire on the stock harness..... where's the other one?

many many many thanks!

 

The stumble really sounds like Accel Enrichments needing to be tuned-- can you post your .msq and a short datalog showing the no-load throttle taps that cause the stumble? Do you have a wideband o2 and is it running into the MegaSquirt? It can be helpful to figure out if AE is the issue and how to fix it. The injectors sound like they're wired up fine.

The diode is a 1N4001 across the PWM Idle valve itself - the banded end goes to the 12 Volt supply, the non-banded end goes to the lead that goes to MegaSquirt (this diode is for flyback purposes on the idle valve).

If you have the on/off style TPS I wouldn't hook it up at all and I'd use Mapdot for AE rather than TPSdot.

Hope this helps Richard! I'll be glad to take a peak at your .msq and datalog...

 

AE. Can you post your settings?

For the MS, 1 wire is the +5v, the other is the signal. The single wire coming from your TPS would imply that you have an on/off TPS.

In other words, MAKE SURE you use MAPdot, you CANT use TPSdot (which is the default setting).

Hope that helps,
Jim

 

I'm not sure, I've played around with the AE a *lot* both on an MSQ that King of gave me, and I loaded up Aussies msq which was exactly the same :(

here's a link to Aussies msq which he passed onto me.



I don't have a WB unfortunately, but it's on the soon to buy list! I only really wanted to hook up the TPS to allow flood clear mode!

 

This has sparked my curiosity as well. That msq has ran nearly perfectly on my car. Follow Jerry's suggestion and get a datalog of your problems. In MegaTune open File > Datalogging > Record and then make your problems happen. Finish the datalog and post it up here so we can have a look at it, well mostly for Jerry, but I'm curious too.

 

I've done a brief datalog, i'm just sat there blipping the throttle, at first straight from idle and other times at higher revs i.e. 2-3000rpm

Engine wasn't fully warm so the stumble is worse, but not much....

thanks for all the help guys!

 

Your VE table seems pig rich to me. Try this MSQ instead.

Jim

 

lol much *much* worse!

what the hell is wrong with my car? :(

here's a datalog with your updated MSQ touching the accellerator now almost makes the car stall!

I don't know if it's related, but MT states that there are 12 warnings when I open the msq file?

 

Also why do you state my VE is pig rich? according to my NB sensor at idle i'm lean, off the guage lean!

 

First of all, the engine needs to be warmed up to able to say anything for sure. Can you plug in the stock ECU back to see if everything is ok, warm it up, and then use the MS again?

Do the following: Dont try to accel in gear, just leave the tranny in neutral. Gently press the gas so that she starts reving up. If it is still refusing to rev up, check your injector connections, there is propably something wrong there.

 

don't need to plug in the stock ecu to tell you that ;-) slowly revving up works fine, when driving under load it drives fine, I've driven to work and back for the past week, you can drive around the problem, but I don't want to, it's horrible.

If you change gear at higher revs you end up with a really uncomfortable shift as the revs drop so much when you re-apply the accellerator.

Re-plugging in the stock ECU results in a perfectly running car...

 

From what I can tell you, MAPdot didn't work for me. TPSdot works flawlessly, I sometimes forget that my car is Megasquirted. Last night I drove it REALLY hard, revving up to 7800 and changing gears in a race-fashion (destroy that tranny!). No hesitations, no bucking, no misfires, nothing. Just smooth (sometimes hard!) acceleration, from 1500rpm till redline. Since I read that you have a 1.8, try connecting the TPS in and use TPSdot.

Just a thought.

 

now that just makes me feel sick....

I can't hook up my TPS as I've only got the on/off style, I intended to connect an analogue version, but so far I've been unable to source one :-(

 

You do have the 1.8 engine, don't you? Or have I misunderstood something?

 

yeah I do, I have an NA8c with the 1800cc BP engine

afaiak the only MX5's with a proper TPS is the Auto? I've only got 1 wire on my Loom that I can find?

 

AFAIK the 1.8 NA has a true linear TPS. The 90-93 1.6 where the on/off type. Hook it up!

 

heh I've just realised that, I've got 4 wires coming out of it, don't know why i've not noticed that before.

Another thing that i've noticed...... the 4 wires coming out of the TPS are:

Green:white
red:black
Red
Black:blue
I guess I need to hook into the Green:white and Black:blue wires, but which to which?

*also* I looked at my Idle solenoild it has 2 wires

Blueink/red
and Whire:Red

now here's the weird bit, I followed a bunch of PDF's that I think Aussie reffered to in his write-up. in by passenger footwell, the wire that is Blue:Pink (as in my IAC valve in the engine bay) is in the spot for the o2 sensor (according to the wiring diagram). wtf?!? do the wire colours stay consistent through the loom? If they do I have my o2 sensor input hooked up to the IAC.....

what colour is the o2 sensor wire?

 

Grab the correct diagram from here:

http://www.madracki.com/miata/wiring.html

It'll save you many headaches.

 

I have done! some of it doesn't match up....

 

Anyway the stumble has pretty much gone! my mate who's installed a TEC2 and a LINK on his BBR MX5 came over and we played with the settings and bounced deas off each other.

Before he came over i tried to connect my TPS via the correct wiring.... no dice, I connected the lightgreen/white and red wire and got no signal to the MS.... Not going to worry about it for now, as in the process of trying to connect the TPS i went to calibrate it *something* I've not deon before as nothing was connected.

By doing this, my car now drives almost like stock, there's a little stumble just off idle, but I've a feeling that this is beacause the stock ECU is still controlling that...

Cold running is still pretty rough however...