trivgar

I got the timing pretty much dialed in with the light and it doesn't seem to like it still. I painted my own TDC marks on the crank and case, locked ignition to 0, set cranking advance to 0 and it's pretty much spot on now. I can get it to run if I give it a little throttle but it sounds awful. Does not want to idle. I took a short video... and here's what the current trigger log looks like.

trivgar

Testing my injector groups, #1 and #2 are on group 0 and #3 and #4 are on group 1. I can feel all 4 clicking on when I test their respective groups. 40 psi at the fuel rail.

Dave W.

Thanks for the vid. I can clearly hear the sound of rich misfires. The lambda gauge also shows the sign of rich misfires since there's raw, unburned oxygen blowing past the Oxygen sensor.
Your injector PW is too high. 7 to 9 ms is even too high for cranking PW.
Lower the PW so cranking PW is around 4 to 6ms, and aim for 1.8 to 2.0ms PW at idle. Once you lean it out this much you should get realistic readings from the wideband and you should be able to fine tune it from there.

trivgar

Dropped the req fuel down to 2.5 and my pulse width is 5.5 while cranking now. It is no longer trying start though. Hmm.. I appreciate everybody's help a lot. Love to get this thing actually running!

trivgar

Little update here.. The only way I can get the car to idle is setting the reqfuel to 12+ and holding the throttle around 10-20% and then it seems to run only on 2-3 cylinders. I have verified all 4 injectors click on (not necessarily at the right time maybe?) and timing light shows spark to all 4 cylinders (dist cap and rotor in good condition still). Here's a screen shot of a log where it was 'idling' about a minute. I was adjusting req fuel throughout to see if it'd make a difference and it didn't until I dropped to 5.5 and it died. When pulse width gets toward 'correct' numbers the car will not run.

shortyboy

I verified your settings according to Peeps post here for low z settings. https://rennlist.com/forums/944-turb...l#post15399824 Check if one of the plugs got fouled from cranking it over adjusting your trigger wheel and settings

trivgar

I put new plugs in yesterday, they were definitely getting fouled. Could my injector group or firing order somehow be wrong? Going to try a compression test for fun and look for vacuum leaks as well.

trivgar

OK compression test is good, plugs on #1 and #2 are very rich smelling and black already​​​, #3 and #4 are totally clean. I have a Lindsey racing injector harness installed... Hmm

Edit: Got it to idle on its own, but still very rough. Req fuel is 12, won't idle with it any lower. Still missing something.

Droops83

VEMS has an injector output test function that will click the injectors on and off. Since a 944 is wired for batch injection, it will probably fire two at once. I can share my injector output settings if need be.

If that is OK . . . .

Is that data log screen shot supposed to be at idle? I notice that the RPM is only 888 RPM, but the TPS is 11%. Did you set up your TPS properly? Make sure it reads zero when it is closed, and 100% at full throttle and ramps up and down smoothy in between. The VEMS doesn't actually use the idle contact microswitch, just flags the ECU that it is at "idle" at 0%. Then, turn off idle control and set your base idle speed using the bypass screw on the throttle body.

I agree that your injector pulsewidth is way too much, but your MAP reading is also high for less than 900 RPM and only 11% throttle, but get your TPS right first. Remember that the speed-density/VE model is based on MAP, throttle position, and intake air temperature. If any of these inputs are out of whack, your injector pulse width will never be right. Once you know those inputs are good, then zero in on injector problems.

Droops83

I edited my previous post to mention about the VEMS injector output test, and I somehow missed this video. Definitely missing a couple of cylinders, hence the difference in plug appearance.

And that jives with how the ground side of the 8-valve 944 fuel injectors are wired: 1&2 fire at the same time, and 3&4 fire at the same time. Check your injector output settings and wiring!

trivgar

TPS calibration went well. I have verified injectors 1 & 2 are on group 0 and 3 and 4 are on group 1. IAT number seems normal to me if that's what MAT is. In the video I had to hold the throttle open a little bit to keep it running. Peep had the req fuel set at 10 when I got it. I came up with 5.5 based off the formula. It seems to run different versions of crappy between 8-12. Anything else it won't start.

Droops83

But are the injectors actually firing? In your video it sounds like it's only running on 2 cylinders. Do the VEMS injector output test key on/engine off and make sure they are clicking.

trivgar

Yup! I can feel each individual injector clicking when doing the test mode, and hear it. Both channels appear to be working. Compression test shows 140 on each cylinder..

Droops83

Is it still running like it was in the video above? If so, you really need to check why it's only running on 2. Triple check that you are getting spark to all 4 cylinders and that you don't have plug wires switched (I read that you haven't installed the wasted spark setup yet).

If the ignition is good, swap fuel injectors 1/2 and 3/4 and see if the problem follows.

trivgar

All 4 plugs are new and have nice spark individually. I just got the injectors back from being cleaned and flow tested. I pulled the cap off and cleaned it and the rotor today. Verified all timing marks are good. I have checked the plug wire order a whole bunch of times. It was running great before the vems install. I had a Lindsey maf and piggyback installed before. I reversed all the wiring changes that were made for that stuff.

Edit: I managed to get it to idle on its own today. But still not right.