Gene,
160 degrees is typically when the cold enrichment is turned off completely. The middle LED on the MS itself is the cold enrichment I believe. If the car dies as soon as the LED goes off, then you know it's related to the cold enrichment. Have you changed the cold enrichment table at all? Also, is your idle control working? Is it possible the engine isn't getting any air? When the engine reaches 160, the MS is probably telling whatever idle control you have to go to its fully closed position. If the engine can't get any air in that position, you simply need to crack the throttle open a little. This may explain why the engine will restart; the temp may go down just enough that the cold start enrichment comes back on, or the after start enrichment keeps it running.

When you say the engine will restart after it dies, how long does it stay running? The after start enrichment could last a few seconds depending on what you have set.

I am about to hit the road myself, but let me know about the questions above. It really could be as simple as setting an idle screw on your throttle plate.

Ken

 

I have had that idle screw pretty wide open, and recal'd the TPS in the MS programme, there and burned to ECU....no go....So I backed it off again, and set the TPS where it was at .5 volts, I have not messed with the TPS adjustment at all, it reads normally....

the TPS cal does say the lo end cal is something like .7 or so, which they say is a weird lo number, but I dunno what to say about it....so I just tell the puter to use it....the WOT position reads normal accepted by the laptop program....wonder if that's it?? why it don't like any lo end throttle closed voltage/value whatever...says it's weird....

 

Gene,
I didn't completely follow you. If I understand, you cannot get the TPS to show less than 0.7V? When you calibrate the TPS, does the voltage signal return to the same value every time the throttle is closed? Also, is the voltage rising when the throttle is opened?

When you said you have the idle screw open, do you mean the throttle screw is holding the throttle blades open? What other idle control do you have?

Ken

 

I"m using a stock idle stepper motor L98 type....yes, I am holding the throttle open with the idle screw.....and I dunno what the computer is saying in that the TPS is functioning correctly and proven with my DVM...

I notice something funny on the stock GM temp sensors though....the program calls for something and then I reset it, and then it reverts back to the other settings, which BTW seem to run better than what the sensors are calling for....like at op temps ie 160 or so, the sensors measure say 200 ohms, and at 45f they measure 5k ohms....both the air and water, and also the spare temp sensors....so by sheer quantity, i'ts not the sensors....or my DVM.....but the program insists on resetting to some unknown thing......but like I said, runs better...go figger....

Ken, I have some definate computer problems, the laptop was barely capable of comm with the MS....the thing only had a floppy, no CD.....and no way to comm with my pc OR the internet to send files to say the sales outfit for help.....I thought it was saving a diagnostic file, and it appeared to be on a floppy, but in fact wasn't, apparently as 9 bytes were registered for program/file size....go figger....anyway, my pc won't recognize any drives.....the only way I got anything at all to work was when my son was here, he had a newer laptop, and so we did a double reverse engineering type thing......which was a temp fix at best....so I need a new pc, which is in the works....hopefully being built to spec so I don't have to worry with those non functioning USB to serial port adaptors....and then to find a laptop with more functionality than that antequated one....like a CD may be nice....;-)......

the temptation is to buy a wide band O2 sensor and toss the thing into self learn, and hell with it....but they want 200 bux for a o2 sensor at my MSQ supplier, and this whole affair is now that I regret even playing with anything to do with TPI, I don't blame most guys for just tuning a carb, and calling it a day.....simply no way to recover costs of all this computer crap on gas savings, and so forth....not worth the time and effort, simply said.....I must have 500 bux in chips for the stock system, and now this MSQ system for another 350 bux, and still nothing....i'ts a money pit....
I have a bid on a ebay carb dual plane intake for it now....going to fire up the carb I have....been a while since I have played with an AVS, but it's surely to get better results than all these damn computers and every excuse in the book to fail or screw up.....I run the gammut with this crap allready....

IMO, it's an analogue problem, and trying to put digital results to an analogue problem is not allways the best solution....

IMO the original Bendix DPFI off the mid-late 70's Caddy Sevilles with the Olds 350 engine, OR a 425 larger Caddy engne was a better solution than any digital system I have ever seen....serious comment....

 

Gene,
I'm running to the airport right now, so not much time. However, I really hate to see you give up on the MS. In my opinion, I think there is probably something minor wrong. Can you email me your Megatune file at home?

Ken

 

Have a good safe flight, watch for islamics....

I can't basically email anything, because the laptop I had wouldn't connect to the router, even via the ethernet cable,....and the damn drives on my PC here don't work, none of them....not the floppy, CD, or Zip....dunno why....they haven'et been used in years....it's an XP machine, so as usual there is some software 'glitch' I can't find....

did notice though, that taking the floppy out of my machine, Ifound my wifes new machine has no inputs for a floppy anymore....lovely...
has a power plug, but no cable jack on the mommy board....

I found if I got mad, and slammed the floppy drive really hard, it would recognize a disc, finally,.....and even go to the files exhibit....
but would not open them.....figgers....

 

Try to hang in there with this, don't forget you're going through a learning curve with this system, and perhaps EFI in general. Too many folks have had success with MS for it not to be a viable solution. When I bought the first digital offering from Holley nearly 10 years ago I had tons of problems with a product that supposedly was ready to go to market. Documentation was inadequate and in some places WRONG, tech support was on their learning curve, fuel maps provided were way too rich to the extent I had to trim 70% out of the map to get it where it would run right. Like I mentioned before, it cost me a set of piston rings (and my labor), thanks Holley. All this has since been ironed out, I've got a good understanding of the product and more importantly EFI in general, and a really nice running engine. Looking back on it now I'd say it was worth it.