Relisys190

iTrader: (4)

Heres a good question. and i'm sure it depends on ambient temp.. and also if the car has been driven in the past hour/two... how many turns does your engine make before it fires??

I was told this is the cheap/poor mans compression test. My old motor would take about 5-8 turns before it started (had to build compression first) when i say turns i mean. vrump..vrump..vrump. Vroooooooommm

My new motor (thank god!) when just recently driven will start with one turn, in the morning it takes 2-3 turns. does this mean anything?

i'm just curious.. and at work..and bored. so talk to you later

-Markus

1987RX7guy

iTrader: (3)

Mine does three vrump sounds then I hear it fire and then the DUALS boot and come online nicely and the flames start up about 10 min after dark

I think it can be the engine but other factors can affect that. A weak starter or battery may cause it to turn over slowly thusly not creating enough compression right away.

Black13B

iTrader: (1)

the poor mans compression test is when you remove the lead plugs and turn the engine over with the EGI fuse out

if you hear a steady pop, you have solid compression..

but anyways.. it depends on if my car has been out or not.. if my car has been sitting in the morning (i believe it has a slight injector leak or something) i turn it over a bout 4 times with the EGI switch off (yes i have a switch that simulates having the EGI fuse in and out) and then after 4 i flip it on, and after another 4 turns it starts to fire up but not quite start then all of a sudden VROOOO

when the car is hot though, sometimes if i just turn the key quickly to make it turn over once, it will go Vrump..........VROOOOOOOOOOOOOO for some reason.. just when you thought it wasnt going it start, it had already fired and was just starting up..

but if the car has been sitting for more than 8 hours, i will usually do the 4 turnovers EGI off then turn the EGI on. ALWAYS fires up with no problems..

ScrapFC

iTrader: (5)

The number of revolutions before starting isn't really a good measure of compression. There are too many other variables. How old are the spark plugs? How well is the motor tuned? Are you still running on the original (wussy 6g) ground wire? (I changed my ground wire and now my starter turns the motor over faster and she starts quicker, too!)




Just my $.02

dr0x

Black13b sounds like my new engine. Im not sure if its the low compression or my injectors leaking causing the problem. Probably a combo of the two I dont wanna pull the UIM again... damn it!

rotary>piston

Does it really matter if you use trailing or leading?

Felix Wankel

leading holes are bigger

Black13B

iTrader: (1)

the lead holes are bigger, and.. well if you've torn one apart, youll see how SMALL the trailing hole is.. i was surprised.. its like.. a bit bigger than a pen tip.. as the lead hole is the size of the thread roughly..

well my engine hasnt had an injector service, and i've tested the compression.. so (depending on your miles on the new motor dr0x, i'd bet its injectors.. or something )

rotary>piston

yeah, I've taken apart an engine, but do you think that size difference really makes that much of a difference in the compression reading? I just tested the trailing holes because it was too hard to get to the leading holes with power steering and ac.

Black13B

iTrader: (1)

try both and see if you get different readings..

i havent tested both with a real tester, so i cant say for sure wether it makes a big difference or not..

skyypilot

you are supposed to check compression using the trailing holes.........