Scrappy_Brap

Before you read, I plan on compression testing it, I'm waiting to meet up with a friend so I can borrow his compression test kit. I have a 6 port bridge that I had build by a local rotary enthusiast/builder, I have RA Classic apex seals, new apex seal springs, Atkins solid corner seals, fd corner seal springs, used side seals and used side seal springs (he said he doesn't even replace the side seals in his own engines) and used housings (with roughly 90k miles on them and looked amazing from what I could tell and he agreed) Issue: I've had many issues and have spent many hours and have gained many gray hairs trying to get it to start and stay running, it's a fresh rebuild but the longest I've been able to keep it running is 30 seconds, (I originally assumed it was a software issue due to the fact I also installed ms3-pro in the car). When cranking it will bounce between 248-252 rpm, when I pour oil down the intake it will crank at 250+ and sometimes when it wants to turn over I can watch the rpms pass 300, when the car starts it doesn't sound like its missing, but it will slowly lose rpm (regardless how much I fight it with the throttle) until it stalls out. I've come to the conclusion it's low on compression because the moment the oil shoots out the exhaust it stalls out (then proceeds to crank like there isn't any oil left in the chambers). At once point we've even pulled it with a car and got it to start up (took going 20 in 1st year for it to finally fire up just for it to stall out...) Anyone have this issue? If so how did you overcome this headache?

t_g_farrell

iTrader: (1)

So this is EFI, not a carb right? I think more details about the build and setup are needed to
help better.

Scrappy_Brap

1984 Gsl
6 port full bridge,
port matched TII LIM & TII UIM
MS3-Pro
LS2 coils
550cc high impedance injectors
GM 3 bar map sensor
GM coolant temp sensor
GM exposed element IAT
Stock s4 CAS
Stock s4 TPS
New EFI ford frame mount pump(Output is plenty

t_g_farrell

iTrader: (1)

Are you premixing? How are you getting oil into the mixture?

Also is there only 2 550cc injectors? Doesn't sound like enough fuel for a bridge.

Scrappy_Brap

Yes I'm premixing, 1.5oz to every gallon, and no I have 4 550cc injectors, sorry shouldve specified

peejay

Probably a setting in the computer, or just plain a tuning issue.

One surprise I had with my first ms3pro install is that cranking RPM in the basetune is set to something really high like 700rpm. Cranking RPM is the switchpoint where the engine runs off of the VE table and various temp/afterstart enrichments, and if it runs off of the cranking pulsewidth map. So if engine speed drops below 700 then the injectors will get a fixed pulsewidth from the cranking pulsewidth map, which is generally way too high for a running engine at cold start. Set it to 300rpm as a starting point. The cranking RPM setting should be a bit over the natural cranking speed so when the engine kicks and speeds up, it goes right to normal fueling.

I'd ask if your engine builder properly set the apex seal length but I do not think compression is your problem. I think you are running off of the cranking pulse and afterstart decay.

Scrappy_Brap

Cranking rpm is set correctly at 300, im new to tuning, do you have any tips on setting the Ve table? I'm really struggling and am at a point where I just want to catch the damn car on fire...

peejay

I am not sure I could really help, my 6 port bridge engines were all on MS1-basic. When I put my current 4 port bridge (Holley manifold, not a Mazda manifold) on MS2/Extra, I had to make drastic changes to the VE table. The fuel calculations are somewhat different. To make things more fun, I swapped injectors at the same time and I never did the proper calculations for my fuel injectors so I know that I tuned around some incorrectness. I don't know if the MS3 calcs are any different but I wouldn't cross things over too much.

Could you post your current MSQ? I'd be willing to take a look at it to see if there's anything glaringly wrong. Every car is different to a degree so the tuning pretty much has to be done on the spot.

Scrappy_Brap

Yes I can, I'll post it up in a bit

Scrappy_Brap

Heres the current tune I have loaded in the car, sorry it took longer than expected to post, my laptop started to flip out

peejay

Before I even get a chance to look at it, I'm going to strongly suggest trying a S4 N/A intake manifold, unless you plan on going with a turbo in the future. I actually ran a T2 manifold on a 6 port engine for a short time and when I put the S4 N/A manifold on I had to add like 30% more fuel in the meat of the powerband. Felt like it was making the power, too.

And unless you're planning on going forced induction, ditch the 3 bar MAP and go with a 1 bar unit. Your engine will only ever really run in the 50kpa-95kpa range and this is less than 20% of the sensor's range.

More later, by that time I'll have looked at the tune (at work now)

Scrappy_Brap

Just finished watching some of your vids, must say Im a big fan of your car! I must ask what the lever in your car does, is it hooked to a switch to activate the rev limiter?

Back on topic, I have intensions to turbo the car, I was inspired by Aaroncakes project TiiNa build, I have the funds to put into the turbo kit and all supporting mods set aside, I just refuse to spend any more money on the car until I can actually drive it and make sure nothing breaks before I spend another 2k on the car lol. the car will be getting a T70 with a .96ar, 2 walbro 255s, 4x bosch 1600cc low impedance injectors (only reason Im going low impedance is because of the cost difference)

KansasCityREPU

iTrader: (9)

I see you have several threads open for the same issue (New Member Tech, First Gen, and General). Might want to close a couple of them.

Scrappy_Brap

Sorry about that, I wasn't sure where to post it so I post it in two places... I'm new to using rx7club, I made the account 2 years ago but just started using it.

peejay

The handle is the hydraulic handbrake. Single-stage master cylinder mounted between the trans tunnel and passenger seat, inline with the rear brake line.

As far as your tune goes, I notice that your have InjB running "cylinder 3". Not sure if this will pose an issue or not. If it were mine, I'd disable sequential injection for the time being until everything else is debugged. (I could NOT get MS2 to run right in "rotary mode", I had to set it up as a 2.6l four-cylinder, old school style. In rotary mode it was reading 2x actual RPM. Dunno about MS3 but given that you are using a trigger wheel it should be OK)

In General Settings, disable "include AFRTarget" for now. And stoichiometric AFR should not be set to 12.0 regardless! (Unless you REALLY MEAN that, I think that works out to something like E50)

Set the rev limiter to something you will never hit like 11000.

Turn over-run fuel cut OFF.

Are you sure those trigger wheel settings are right? The FC wheel has 24 teeth but it turns at half engine speed. So it is 12 teeth per engine revolution not 24.

Your warmup enrichment curve needs work to say the least. It needs to be 100% at over ~150F. Yours never goes out of enrichment.

Afterstart enrichment is also ridiculously long. Way way way too long. ASE is only to cover up for a few seconds of the fuel "wetting out" against the runners on a cold start, a figure of 350 would mean you would be on ASE for over a minute.

Another thing you should do is just go over The Basics. Does the reported RPM seem right, do the air and coolant temps read the same as each other and the same as your environment after an overnight "cold soak"... if those are wrong then nothing will work. Your cranking fuel pulsewidth should be in the 5-8ms range, when at idle it maybe should be 2-4ms-ish. Not terribly sure.

Scrappy_Brap

The main settings were copied from aaroncakes base map, ms3 is 100% rotary compatible(so Matt at diy said) it shouldn't need all the tricking that ms1&2 needed to run a rotary,

As for the ASE, would you mind giving me some tips on how to set it correctly?