The engine does not appear to be kicking back? What would cause that? Like a misfire from off timing?

So, this is a weird problem. We just did a head gasket on our high school shop gsx and after we finished it now only cranks for a split second and then the starter disengages. It does it consistently. If we try again it will crank for a split second (less than one second) and then the starter...

Head gasket replacement in progress. No visual sign of issues. Chambers held fluid tightly. Hoping for the best. Bought ANOTHER felpro permatorque gasket. (Those are expensive!).Stay tuned. Only 2 weeks left with my seniors. 3 weeks total...

Yup, that's what we did last time. Everything sealed fine. So, we'll pull the head, check for warpage again, last time we even replaced the rings because we didn't want to pull the head and not know why we had low compression. I have more rings, we could do it again, but I don't see why we'd...

Yeah, we did a leak test with the head off. Put fluid in the combustion chamber and it held fine. I may have the kids to a leakdown test before disassembly.

So, we're beginning teardown. Hopefully we can figure out WHY we had low compression..

So after all this, we tried the Blue Devil head gasket fix.... and now we have fine compression on cylinder 2, but low compression on cylinder 4?!?!?! That was the cylinder that we previously had low compression on. We did new rings and a head gasket and we bought the best gasket we could...

Thanfully we have 0% milkshake... no boys in this yard.And yes, a couple studs were loose. I do have a bottle of the Blue Devil sealer on the shelf. And IMHO, I'd rather swap a radiator (we have an extra) than do the head gasket again... but this is shop class. The kids are learning.

One problem we may have had was that we used moly assembly lube with our arp head studs. I don' even remember what torque we put them to, but I remember that I did a lot of research so that we had hopefully done it correctly.

PROGRESS (but not the kind I wanted)So, after adjusting the MAF adjustment, I felt like there as some improvement, but then I started thinking... We are inside and hooked up to a vehicle ventilation system. I unhooked our exhaust tube and lo and behold, white smoke. Not horrifically bad, but...

Yeah, I've never messed with the MAF slider. That is the way the chip was burned. I can zero that out.

OK, from reading around... things to check-ICM Recheck ISC CASI have another ICM on a parts car. I've tested the ISC before, but can do it again. I would hope out CAS works, it is band new...

Here's with STFT and LTFT... I forgot to turn it off, so it is long, but you can see what it looked like at the beginning.

I hooked up the WBO2 to the rear o2 sensor wires. Here is the log-

So, from what I have watched, the fuel pressure stays at 42.5-44 (hard to tell on that small dial. I think we have it set between 42-44.).The wideband sits pretty happily between 12-13:1 when warming up. That said, if anyone wants to save me the horrifically difficult job of hitting the search...

Here is the log. I just let it idle until it died. What's odd is that I set the idle position to 0%, but then it was back at 1%.I restarted it twice after it died. I tried lightly revving the motor some before finishing the log.The AF was around 12.5 the whole time. But right before it...

Ok, so we can't tell if it is running better, worse, or the same.We're kinda getting desperate at this point.Maybe we need to go back to square 1 and check everything from the beginning.Right now it was roughly idling at around 1100. Bobbling up and down 50 rpm. But once it gets up to temp...

Link has that calculator built in so I usually just go with that...

And we're back... I think we're going to try swapping in the 540s today and see if that changes much.Do I need to change anything on Link aside from the fuel setting?

Well, the day isn't over...What would be the sign that the springs were not on correctly? Like I said, the throttle plate opens and closes properly. As far as I can tell. They were on there pretty tight.Also, we still haven't tried the 540s... Might want to do that and just see..

The TB is definitely closing all the way. We didn't mark the springs, but I felt pretty confident when we put it back together. And FWIW we had this problem even before we removed the TB. But we did fully tear it down.So, spring break is here. I'll be gone for 1.5 weeks. Hopefully we'll make...

So, call me crazy, but I stuck the .18 feeler gauge in, and then I set it to .63V, Which gave me like .57v with the feeler gauge removed. Now, I checked it a few times, all was good, but then after starting it, it went up to about .69v when off the throttle. That said, it was trying to idle at...

So, Jafro just set the TPS to .63v watching it on link. Is that a good method? Other's have said that using the feeler gauge is the ONLY way to do it.

So, I played with the TPS some. I'll try it again tomorrow. Seemed to help. It ran much leaner. Was running at 14:1.

I unplugged the MAF, it ran really lean. 18-20:1.When I pulled the plugs, they were legit rich. Covered in black.

Yeah, I have to hold the pedal down to get it to start (almost like with an older carburetor motor when flooded.) So here is a log. TPS looks good. Fuel at -48.8. I start with a little throttle, and then slowly let off. Eventually she just dies.

Ok, so I have the TPS adjustments enabled in link. Does that not eliminate the need to calibrate it at the TB? I've calibrated one before, but was under the assumption with with link I could just let link do the work.Also, we are CONTINUALLY having kids leave a door open, or the key on, so the...

I haven't tried swapping out the ISC... though I believed we tested it last year and it was fine.

Ok, I was able to get a quick test in before the students got here. I think I added the correct values. I just don't see where I can review them.So this is a log from a cold start all the way until it dies at 190 degrees. I turned out the BISS towards the beginning of the run, hoping to keep...

So, according to the wideband and my spark plugs, I'm running rich. And I thought the F02 was reading rich also.I can start it up and try to get in another log with more things set later today.

I didn't have that set. All of my previous logging experience is with MMCD and pretty basic.I can make a new log, what would you (guys) suggest I log?

We screwed the FIAV in all the way to essentially bypass it. Coolant temp steadily climbs on ECMlink as if it is reading properly. We have set the throttle plate and adjusted it a couple times to be sure. I think the BISS is turned out about 1.5-2 turns.

It does have an AFPR, I'll have to check that.I pulled plugs, they look rich. One had some oil around the threads. I'm going to look into that. It appeared from a quick and simple power balance test (via pulling injector harnesses) that the inner cylinders may be making more power than the...

And yes, it does seem to learn out as it dies. But quite quickly. You can see from this video. I don't have the wideband setup to log yet.

I'm not sure what all you can learn from this, but it might spark an idea.

Yeah, ECMlink v2 is flashed for the 880s. I can easily go in and change it for 540s. I forget what brand our cams are. And I agree, it should still idle at much lower than 1500. I guess I was just noting that it won't idle like a stock cam.So, it idles at 1500 with an A/F ratio of 12:1. Seems...

So, I have a set of yellow evo injectors. That we could just try swapping out to compare. (this thing does have a 280 cam on it, so that may be playing a role in our idle). The only problem with the injectors was that two were missing the pintle caps. I have some extras, but a different style...

Well, since we got things back together we have had leaks at the fuel rail. Again, kids try their best, but this is their first time doing things. You should see my kids who are taking apart their lawn mower engines for the 3rd time because they keep making rookie mistakes. I.e. swapped valves...

Leak locations- Donut gasket on injector 1. Still... AFPR (haven't addressed it yet) Line to boost gauge. It was just one of those hard plastic lines shoved into a vacuum line with a zip tie. We tried a second ziptie, but we'll need something more secure. Also, just noticed a tiny leak on the...

Yeah, we noticed the injectors were leaking too. Well, air from around them, not fuel.I'll post an update at the end of class today. We are seeing improvements. It is still dropping pressure at 1psi per second. I'd love to see it hold a bit longer.

Gurgling from under the valve cover? Sound like oil glugging? When pressurized to 10psi. We found new vacuum leaks. Working on those.AFPR- there is a tiny bit leaking from the top where the adjustment screws are. Is that normal? I.e. the leaking pressure when setting it, or do we need to...

We never took it off. But I used the "better looking" BISS off of the two TBs, but the original one never leaked, so we just swapped them out. And we did just try some copper rtv (not really high temp, but it's what we had handy) on the TB. We swapped out a pinch type hose clamp for an actual...

Well, update, closing the FIAV obviously helped. But, after taking apart the TB, we obviously have some boost leaks now. Lots of tiny ones. The TB elbow gasket isn't sealing, BISS is leaking now (we had 2 TBs and we used the other screw), we found a couple others too. But, I'm hopeful that we...

Wowza, well we got the TB rebuilt today, but not installed yet. What I can tell you is that the FIAV area was filled with a black tar like substance. Quite nasty. I'm hoping that is pointing towards it being the problem.

Well, we had an extra throttle body, gaskets, and new MIL spec shaft seals, so I think we're going to pull the TB off, do the trick where you just screw the FIAV in all the way (tell me no if any of you disagree with that plan) and then cap off the cooling lines to the TB. And then report back...

FIAV stuck open?

Throttle cable is far too loose. Left it that way to fix later. SAS was loosened all the way until not touching. TPS adjusted via ecmlink. We THOUGHT we had solved all of our vacuum leak issues, but we may need to keep checking.I'm also working with a bunch of high school kids, so...

Ok, so we may need to go back and look at the SAS again, but currently we had the ISC position at 32, but the rpms were around 1600. I'll loosen the SAS and try again, but we did 1.25 turns past touching, as the instructions said.

Ok, yes the ISS was the ticket. I bet we adjusted it back when we had two dead cylinders... So now we have to legit tune.. How exciting! After 3 years, this car might finally move under its own power.

Yeah, I have not gotten that far yet. As always we are plagued with having short class times, and 20 other projects going on. I'll look at the ISS *(Idle set screw? I think that's right) on Monday probably.