takeshiro

so i got my motor built by the local "rx7" guy... and it has a hard time starting. he said it shouldnt be hard to start because it has new housings...

s5 block
new housings
rx8 rotors, shaft, and hardened gears
microtech lt10
550primary
1600secondary

he installed racing beat dual sheave pulley, i dropped in the cas between 10 atdc, and 0 tdc (5 atdc), oil primed the motor and fuel system... went to start it and fail. crank crank crank almost wants to catch but doesnt. pull started it and it ran.. but a little rough, i assumed it was loaded up from the assembly lube and atf and fuel but i ran it for 45 mins and still was rough.
is this normal? what should i expect from a fresh build with new housings. i had the idle set to 1500 cuz once i got to 750 ish it would shake like crazy and die. tried to start it up after and it wouldnt start. im wondering if my cas is set incorrectly however i triple checked it and its lined up at 5 degrees.

any input would be great.

AGreen

iTrader: (11)

#1 - Please don't use words like "cuz" in the place of because. It's not polite to murder English like that.

With a fresh rebuild that includes new housings, you should have very good compression. Try a compression check. If you paid for a rebuild with new housings and get anything less than 100 psi on each face, you need to take it back.

rx7_FREAKKK

iTrader: (1)

I would not suspect the engine Right off the bat. I would check and make sure everything is hooked up right, And check for any loose intake hoses and what not.

nycgps

iTrader: (4)

watz wrong with cuz? I think cuz is fine cuz it means cuz.

Yep

ben.farnath

I'm going to save that one for the next time my sister texts me. That is gold!

joeylyrech

iTrader: (11)

Okay you can have brand new housings,irons,seals ect but that only counts for some of the compression,if side seals were not fitted right,corner seals installed wrong(yes is possible corner seals go in a certain way)the motor will suffer and compression will never build up.

Aaron Cake

iTrader: (1)

Is this a turbo engine? That's a lot of fuel for an NA and very high compression for a turbo engine.

Sounds like is just needs to be tuned. Less fuel at idle. The stock Microtech map doesn't have enough fuel in the crank map (hard starting ) but has way too much in the main fuel map.

takeshiro

Yes its turbo im spooling a Td06 20g I'm gonna pull my upper and triple check stuff and to compression test. Shouldn't it start with base maps with stock primary injectors?

j9fd3s

iTrader: (3)

if the engine was built properly, and everything is installed right, the ECU will need tuning. an engine with a lot of compression needs less fuel than a tired low compression one.

takeshiro

Well had a look at all my wiring and everything looks good. Did compression test.... 90 psi front 99 psi rear... Wtffff Will be talking to builder

AGreen

iTrader: (11)

That should at least start it, but I don't think compression should be that low. And is that 90-90-90 and 99-99-99, or did you not remove the schrader valve (or hold the pressure bleed off down) when you compression checked it?

beefhole

iTrader: (29)

any coils/plugs wired backwards?

takeshiro

Schrader valve out
Front rotor
55 55 55 - faces look pretty even
Rear rotor
85 85 85

Schrader valve in
Front rotor
90
Rear rotor
100

I talked to one of the guys at the shop and he said compression is low because the seals need to wear into the housings blah blah blah. Is this right? And I might have a problem with my primary injectors... I noticed the rear plug is more wet than the front one...maybe the front injector is plugged or spray pattern blows causing rough running condition.

Coil wiring appears to be correct, no crossed plug wires lol

beefhole

iTrader: (29)

^try another pair of injectors. Also at this point, do a flood clear. Crank the engine over, but disable the injectors. Let it get rid of all that fuel that's soaking your plugs. Then put a little oil in each housing, and turn it by hand a few times. Then start again.

rx7_FREAKKK

iTrader: (1)

When Engine is Flooded Compression will be very low, When going from Old engine to New Engine the Settings and idle will be off. Im sure it will need to get tuned to the new engine as i have had the same issues when changing engines. I always had to tune idle Among other things

Furb

iTrader: (2)

Compression builds up after some time with a new engine, thats not just rotary..

Running in an engine is nothing more then taking it a bit easy untill everything has mated a little.

Sounds to me its tuning related.
A pull start worked, that means it skips the cranking cycle and thus starting it in the main map.