Well, I spent an hour or so earlier and managed to get the VE table reset. Unfortunately, it may be off due to the vacuum leak. I also pulled about 5* out of the entire spark timing table (with the exception of a few cells used for starting). It's no longer skipping when I stab the pedal.

Still VERY hard starting, both cold and hot. Although I'm consistantly running about 35 kPa.

Still getting the sucking noise from the driver's side valve cover. I've got a spare gasket and will also go as far as to put a heli-coil in the one bolt hole so that I can be 100% sure I can get the valve cover tight. I also need to replace one vacuum line running to the charcoal canister because it seems to be a bit too big for the one fitting coming from the intake and causing another small leak.

 

Well, all of the problems so far have been fixed. Intake completely regasketed, rocker arms tightened, vac leak gone (as long as I leave the charcoal canister disconnected ).

New problem. The MegaSquirt is messing with me, I swear. Starts just fine cold. Runs just fine cold. Hot? Forget it. Somewhere along the line, the MS sees fit to add about 10-15% more fuel to the mixture and performance drops out the bottom.

First vid, barely off of cold start, coolant may be around 120 degrees...

http://s988.photobucket.com/user/mav..._0641.mp4.html

Second vid, about 3 minutes or so after I cut off the first one. I DID NOT change ANY settings in the MSII. My tuning laptop wasn't anywhere near the car. I didn't touch the engine... Just let it ran until the coolant fan came on and then shut it off before starting the recording and restarting. You will notice that a few seconds or so after restarting, the MSII decides to work its magic and FUBAR the mixture... The idle starts fluttering and then drops to about 1100 RPM and stabbing the go pedal has a MUCH different exhaust note.

http://s988.photobucket.com/user/mav..._0642.mp4.html

Oh, and as for the exhaust... The only part the same is the muffler itself and the outlet elbow (well, the elbow is new but the exact same as the old one). The tail pipe is no longer the $30 resonating tip that was about 3" in the inlet. Of course, the exhaust starts with PaceSetter headers flowing into a Magnaflow 93441 direct fit V8 3" cat, which outflows into a Walker 2.5" mandrel-bent intermediate pipe (which, ironically, has the same diameter at the muffler connection as the pipes in the current muffler). Eventually, I'd like to get one of those Quiet Flow mufflers...

 

^ this is of no use to you but ya know mine was/is like that stock, once hot where the stock fan came on, it was sluggish and down on power.

solved that by removing AC stuff and a goodair dam, now the temp never gets near 200 and the stock fan never comes on longas your moving. And it runs crisp and responsive all the time.

now stop at a long drive thru and forget to turn on the fan manually [ to keep temps under 200], and let it get over 200, bye bye power.

you can see the needles is just before the big line, runs awesome in that range, let it get past it, into 200s..............

 

Oh, I know that the fan has a huge drain on the engine... I think the idle kPa goes up about 3-5 points. Mine's set to turn on at 195*... If I set it higher than that, for some reason the lower radiator hose blows out of the coupling at the radiator (stainless hose and I've even tightened the SOB with a ratchet) around 205-210 degrees.

I was watching the Realtime display tonight as I was experiencing the difficulties with the AFM. For some reason, after a hot start (not hot enough to turn the fan on tonight, however), everything will be fine for a few seconds (probably a shorter duration with higher ECT), and then the injector PW randomly increases THIRTY PERCENT, from about 1.6-1.7 ms to 2.3 or so ms. With no O2S input (disabled EGO correction below 1600 RPM), TPS change, MAP change, or MAF change.

Seriously, I'm about to ask if there is a way to get the MS tables onto a GM calibration and get a 165 ECM before selling the MS and letting someone else deal with it. I've put exactly 10 miles on the car in the last 32 days because it's undriveable except for really short one way trips.

 

I'll trade you a '165 for your MS, to get more familiar with MS but, I'd suggest going with a '7730 instead, it will likely be easier to tune.

I'm not Sure I'd want to use any existing MS settings since they don't seem to be working. I'd start from scratch on the tune, either MS or with a GM ECM.

 

I have a 730 but a 165 is a direct plug-in. And I already removed pretty much everything from the harness having to do with the A/C and emissions components (I'd have to turn off MALFFLAG 32 as there is no way the EGR on this setup is ever going to work) including the blue non-A/C radiator fan wire that's supposed to be grounded with the absence of the air conditioner. When I say removed, I mean there is no trace of those wires anywhere in the harness as I even pulled the remnant out of the body pass-through on the passenger's side.

The fuel and spark curves in the MS are fine. They've been road tested. I don't know what or where the problem lies that the MS starts adding about 30-40% more fuel OUT OF NOWHERE. It's running fine right up through operating temperature (160* closed loop temp) and then the engine randomly starts bogging down as the injector PW goes up and the fuel mixture goes from slightly lean to stupid rich... It even sometimes runs fine up to the 195* point where the radiator fan comes on and I shut the engine off to check the hot cranking PW (which I finally got set), but then runs stupid after I restart.

 

I'm not aware of any wire on the '165 or '7730 that needs to be grounded without an A/C system...

Since the MS and the GM ECMs calculate fuel delivery differently, I wouldn't want to attempt to use one table in a different application. MAYBE as a really rough starting point, but I wouldn't trust it. I'd trust something that was set up for that style of ECM and from a similar engine, but not across different systems. Hell I don't even like to copy from a GM ECM to a different GM ECM, since there were a few different fuel delivery models (formulas) used in GM ECMs over the years.

 

like ive said before post a datalog and msg file, ur not going to get any help without it , here or the ms forums

 

Um, well, you try running a 730 with an electric fan and not grounding C2 (connector 2) D12 (dark blue wire, happens to be by the passenger's side engine ground at the back of the cylinder head with the other 2) without air conditioning. You'll get the same result you would if you left the A/C fan pressure switch disconnected on any other system. I can guarantee it since that's what happened when I did it. It took me a couple days to figure out why I couldn't get the fan to not come on with the ignition when I did the full 91 harness swap.

project, I have enclosed a zip of the datalog from the other day and the MSQ. I promise you're not going to find anything and that's what doesn't make any sense. It's just running just fine one minute and running like garbage the next because the MSII sees fit to add almost half again as much fuel for no reason. I had even completely disabled the O2S and still it ran like crap.

 

Umm, I have... in several vehicles...

I don't believe I've ever grounded C2, since it doesn't show in any of the diagrams I have, and in my conversions there hasn't been AC.
I've also never grounded D12, in fact I've removed that pin on conversions, without AC. I believe that D12 triggers the primary fan to engage when grounded, but is not necessary to engage the primary fan when based on CTS input.

I always run an E-fan when using ECMs capable of running them.

I've never had an issue.

When I get a chance I'll have to do some bench testing to verify operation.

I just looked at my bench harness for my '7730 and don't have a wire in C2 or D12, and it triggers the fan output just fine based on temperature input.

 

It is a difference between masks $88 and $8D. $88 will run the fan when pin D12 is open.

RBob.

 

ur tune file is corrupt !!!!

did u start the tune from scratch? if u did this s a big nono with ms2 as a;ot of the values will be screwed up

 

i see a few things wrong first up is the ase settings are wildly off and some of them have no values at all

this explains the sudden rich condition after a period of time when the ase is kicking off


what ms2 code version are u running , cause when i load it into tunner studio or megatune both programs give me a file signuture error , along with 4-7 tune file errors

 

req fuel is also off by about dbl
fuel settings should be 2 squirts alternating
ego settings are wrong
why are u trying to use afr tables with a narrow band o2 sensor?
are u using a maf sensor? if not u have the ms setup to use a blend of maf and map which will be a huge issue

let me know what version of code u have and what size injectors
i will make u a base tune to get u started , with all the errors i see its no wonder ur having issues

 

That's a huge difference there. Just saying that not grounding something on the '7730 will cause a fan to not function, or to function incorrectly is not an accurate statement.

I'm quite sure I've ran $88 on my bench and have not noticed this behavior, but I'll have to test it again for sure.

Any codes that I have run in the '7730 on actual vehicles and from what I can remember on my test bench have not exhibited this behavior. What would be the reason for this?

 

There is a pressure switch on the high pressure A/C line. The switch is normally closed (grounds D12), and opens with high pressure. This tells the ECM to run the cooling fan.

As for the '7730 does this or that, I agree, there are 12 different masks that use the '7730 ECM. Even running a 1-bbl TBI set up on 4-banger cars. Most interesting is that those MEMCALs don't have a knock filter. So either they don't use one or it's an external filter.

RBob.