Fritz Flynn

iTrader: (263)

You can loose some crazy time when you drop down a gear and it's also really hard on the trans, engine etc....

If I'm not running in a time trial I'll even shift into 5th going up the esses just to keep the rpms down. I'm sure you're aware but the wear on everything is seriously increased as you increase those rpms.

Section8

iTrader: (6)

yeah, good point. i remember you upshifting to 5th in the yellow track beast when i rode with you back in 05 at my first event


I just pulled the plugs, they need to be replaced but the leading plugs on both rotors were dry. Compression tested both and got compression. hard to get exact numbers on this harbor freight gauge, but the lowest i got was 60, highest 90. The coil pack doens't look discolored, but I can barely see it right now, i'm going to go back out and pull the TB off to get a better look at it.

Section8

iTrader: (6)

got the coils out. Not sure what is meant by discolored, but here's what they look like

Fritz Flynn

iTrader: (263)

Coils look fine

60 psi is likely a blown engine probably not an apex seal but a side or corner. I have a bad engine now that would start and idle fine but had smoke and heavy break up under boost maybe as a result of bad combustion because of the low compression.

Section8

iTrader: (6)

but what i don't understand is why it doesn't still run? Seems like even if it was bad it would continue to run. Trying to decide now if i should just source some used coils to throw in and see if it runs or not.

turbo10th

iTrader: (6)

Rotarys run blown, blown 5 up, and all drove home+ more lol. Hell one i drove for a month cause it was my daily. That sucks but i would stick with a rotary. Guy i know swapped a 2jz in his and is going back. Its just not the same. Those coils look normal by the way and the only real way to test them is with a spark tester.

Mahjik

iTrader: (1)

I agree with Fritz that the engine is still likely blown. Keep in mind that a cold compression test will usually read higher. It is strange that the engine completely died and wouldn't stay running, yet your lowest compression pulse was 60 PSI. That's usually enough to run the car, just not run well.

Here's the test for the coils:

Section8

iTrader: (6)

yeah i couldn't warm up the car propery for the test since it won't run longer than 4 minutes

Thanks for the test diagram man. Need to find an voltage meter since mine got smashed somehow.

Brent Dalton

iTrader: (31)

I'm assuming you did the compression test with the valve stem in the piston compression tester? If so, you can take it out with a valve stem puller and verify how many pulses you have on each rotor.

jantore

How does the engine sound? And how does it idle when it's warming up? Does it run smooth for a little while then run rough and idle bad and die out?

Sounds like a chipped apex seal or broken sideseals im afraid

So think you should just pull the engine im afraid.

JT

Section8

iTrader: (6)

I held the relief valve in while I had the wife crank the car, I was getting 3 pulses on each rotor but it was hard to read the exact pressure on each. For the readings i'd have the wife quickly crank and i wouldn't hold the relief valve so i could get a peak reading - but that wasn't exact for each pulse. I should have just hand turned the engine to get readings I guess.

When it will start, it starts smooth and idles around 1500 steady for about 2 minutes, then starts going up and down in the rev range for about a min before finally sputtering out with a backfire.

Fritz is going to hook me up with a set of coils/wires/plugs that I'll throw in to see how she runs. I'll try those out and if it's still acting the same I'll move ahead with pulling the engine.

mdpalmer

iTrader: (24)

Hi there, just wondering what your engine/turbo setup is... and what kind of temps you were seeing during that last track day.

-boost pressure
-AFRs under boost
-oil/water/air temps (max & sustained)

Best of luck to you.

Section8

iTrader: (6)

i'm running stock twins in simplified sequential, downpipe, mid pipe and cat back, intake with a PFC base map for the mods. I haven't seen boost much beyond 12psi on the PFC tell tale - usually it reads .82bar. water temps at vir were around 195c, oil was around 220-230 i think. I didn't look at AFRs

Fritz Flynn

iTrader: (263)

Joe,
You might get away with that on 100 octane but you're seriously flirting with disaster because I'd guess in 4th gear you're likely seeing 13psi of boost on that base map with intake temps over 50c and that's a very good recipe for a blown engine. Once those intake temps are the 70c range c16 won't save you lol.

If the engine is healthy I'd suggest getting some 1200cc secondaries and getting Ray to tune it before your next track day. Then I would advise to not run more than 10 psi (you could get ray to make a restrictor plate for the exhaust) if your intake temps are ever over 50c. If you can control intake temps (can only be done w/ a v-mount or extremely well setup smic like crispy or peter) than you should be safe at 12psi. Once you go over 12 psi w/ the twins it's really hard to control all the temps and the turbos will basically die a fast death (oil temps) if the engine doesn't go 1st hehe.

Once you get this puppy sorted **** a v8

mdpalmer

iTrader: (24)

Thanks for the reply. The PFC commander reads in kgf/cm^2, not bar. 1 kgf/cm^2 = 14.2 psi. 1 bar = 14.5 psi. The commander says you had 0.82*14.2 = 11.6 psi. Only thing is that I wouldn't trust the PFC readings for boost unless you calibrated your MAP sensor. For an uncalibrated sensor, some people report that the PFC UNDER-REPORTS boost level, at your indicated level, it's probably around ~1 psi, so you may have been running ~12.6 psi or so. Other than that sounds like your temps were under control, except didn't hear anything about AITs.

Any idea how many miles on this engine? Street/track?

Are you running an AST?

Sorry for all the questions, just trying to gather all the info possible

Thanks for posting Fritz, every time someone posts a "motor dead" thread, I really want to know what the circumstances were and what the running condition of the engine was (temperatures, etc)... I am still a firm believer these engines just don't blow up for no reason. It helps when someone who has been around these cars for a while (esp on a track) chimes in. Like I've mentioned, I blew up an engine a few years ago now because of a lean condition due to high AITs, too much boost, and crappy 91 octane

Fritz Flynn

iTrader: (263)

When it will start, it starts smooth and idles around 1500 steady for about 2 minutes, then starts going up and down in the rev range for about a min before finally sputtering out with a backfire.


Hey Joe,
I just read this and putting this together w/ the low compression readings I'd say that's sounding like a blown engine. Lots of folks will turn the idle up to 1200 or 1500 to sell a car w/ a blown engine because it will idle fine in upper RPMs. Once the car warms a bit like after 2 minutes the idle settles, starts bouncing and depending upon how badly it's hurt will either run or shut off. I'm also guessing you have hard time starting if it's hot?

I'm still keeping my fingers crossed that it's ignition though, you will probaby get those parts today if they didn't show up yesterday

If it's blown don't loose faith in the triangles and pick up a nice engine from me

Section8

iTrader: (6)

Thanks Fritz - I have been meaning to upgrade the injectors since i put the mid-pipe on but just haven't had time. Maybe (assuming your coils work) I should put the stock cat back on until I can get everything else sorted. Of course you know I'm still running the baby stock IC which is on my list to upgrade too.


No worries on the questions, I appreciate everyone chiming in to help me out

I didn't know that the PFC under reports boost level. Damn i feel stupid now. Granded .82 bar is still high, but I still was thinking that it wasn't THAT bad.

This engine has about 40K miles on it, and I'd estimate that last 12K were all track. It's been trailered to/from track the last 2 years and hasn't even been registered for the street. It was a fresh reman from Ray at Malloy when I bought the car in 04. I do have an AST and Fluidyne aluminum radiator, along with some home brew ducting to improve air flow to it.
I got the coils/wires/plugs yesterday, but I've been so busy with work I haven't even had chance to open the box. I'm hoping to get back to the car on Saturday morning.

By the bye, what is the condition of the engine(s) you have right now? anything ported?

Fritz Flynn

iTrader: (263)

Pm'd you about the engines.

Section8

iTrader: (6)

Got the new coils, plugs and wires in - I actually got the car back together quicker than I took it apart which is a first for me - and got the same result. Car started up quick, idling around 2k, then started fluctuating idle. I thought it was going to be good when it settled down to around 1K after about 2 minutes, then it just died with very little fanfare.

Aside from the engine being bad - could it be a crack sensor or ignitor?

Section8

iTrader: (6)

oh and it won't restart again now either. just cranks and cranks.

musclecarconvert

iTrader: (4)

I had this exact same problem with my last one. I dont remember how they fixed it but it wasnt a blown motor. It was a sensor I want to believe on the front of the motor. The bolt holding it in backed out and it started doing this exact thing. I was able to get it running for about 2-3 mionutes and then it would die but it would send a massive backfire with tons of black smoke. I wish I could remember what the exact problem was to tell you to try that. Maybe someone will chime in with what Im talking about

Jeremy

Fritz Flynn

iTrader: (263)

I'm guessing the crank angle sensor was the cause on yours but I'm still pretty sure with Joes engine it's a compression issue.

Joe,
If you keep the rpms up w/ your foot in the gas does it shut off. If it doesn't I'd say it's compression if it does there could be something else wrong.

These are all classic signs of a blown/low compression engine:

cold start no problem
hot start not happening
high rpm smooth idle
low rpm lumpy idle and won't continue running

Now add in the low compression you saw on the tester and you pretty much have the answer.

Section8

iTrader: (6)

yeah, i'm really thinking that it's bad too. I will try holding revs with the gas today and see if it stays running.

Section8

iTrader: (6)

started it, gave it steady gas when it started to stumble and that really didn't help. It kept it going a bit longer maybe but then it just started sputtering really bad as I gave it gas and then it backfired and died.

Fritz Flynn

iTrader: (263)

1st I'd verify that compression again. Make sure you have a good seal/o-ring on the tester. If it comes back good I'd start worrying about the primary injectors possibly sticking open or leaking or the secondaries leaking. Although I think you mentioned the plugs were dry at some point so make sure you have good fuel pressure as well. LOL.....there could be any # of things wrong or it simply might be a blown engine but usually you can keep those running if the car starts.

Anyway good luck w/ it and if you need any parts I'll hook you up