marcus219

Allright...please read this whole thing if you have time, I'd like to get you to the point where I am so you get all the info. I bought a engine from a local wrecking yard, out of a 1987 Rex...before buying the engine I did the chug test on it. I got 1 decent chug for every 1/2 rotation of the flywheel...so a total of 6 chugs for 3 rotations, the chugs were pretty strong and gave my thumb a good push as I had it over the spark plug hole. I figured it would not be 100% b/c of the engine being very cold, it sat for 1 month. When I bought the motor it had no primary injectors, the holes were just exposed and the fuel rail off to the side, the upper intake manifold was loose and just resting on the lower via the studs. The thing that conerned me was that there was sand all over the block, especially around the open injector holes..I did my best to clean it off and keep sand from falling down, but I could see sand on the injector screen inside.

One of my 7 buddies (Matlock) helped me pull my other engine and install this one. First thing i did, was get all the sand I could off of it, and feed it some Marvel Mystery Oil. I was worred that it might have a stuck apex seal and knew that there would be plenty of carbon in there. I put it through the spark plug holes and the lower intake manifold, and cranked the engine to be sure it was evenly distributed. The engine vacc. harness was already hooked up, the only lines WE TOUCHED were the oil injector vacc. spider harness (which wasnt even there) and the vacc lines to the upper intake manifold and the dynamic chamber. We installed all this correctly, by looking at the manual, using our heads, and looking at Matlock's RX-7 which is running 100%. We installed the motor and got everything hooked back up. I aligned my Crank Angle senor, used a new upper to lower intake manifold gasket, I bought to plugs, put them in. Tried cranking the motor but no go...it sounded good when it cranked, but it would not fire. It would attempt to grab and you could see the motor torque. FINALLY, we got it start with atf in the chambers and tow starting it...it ran for a total of a hour and half. It wouldn't idle below 1,000..so I adjusted it to about 1500. The idle held fairly strong there. I drove it around, at total of about 15 minutes. The engine had 0 power...doing about 40-45.if you tried to go into 4th it would try to die on you. The car eventually died and left me stuck...when it died, it didnt sputter, but the RPM just when straight to 0. It felt just like my engine when it blew!

I conducted a compression test before AND after the engine ran. Results were the same...

Front rotor: 90-90-90
Rear rotor: 30-30-60

I called the j-yard, they came and got it...now heres the BS part!!!

They told me 1/2 of the vacc. lines were installed wrong (like i said above, we touched very few, but whatever), he said my cat was clogged, and my spark plugs were dripping with fuel. If someone can please clarify this for me, my cat being clogged WOULD NOT be the cause if the compressoin results that I got. Both rotors use that same cat to push exhaust through!, you can drive with a clogged cat, it will lack power and the piping will glow, and the cat worked perfect on my previous engine..its a Bonez high flow cat...now get this...he told me that high flow cats on rotaries are a very bad idea, it will make it run horrible. ******* STUPID ***, the cat is nothing but a tree hugger and power robbing item for the rotary...it restricts...why would a high flow be worse... He also tells me my injector wires were just plugged in, instead of clipped, ya big F'ing deal...those things break easier than hell, and i wasn't plalnnin on running them like that, they can pop off easy, my goal was to get the thing running, and fix little stupid crap like that later. I undertand that havin vacc. lines crossed would make it run like ****, but help me with this too please, I could have every single vacc. line crossed on the engine, it would run horrible, or not run at all, but that would not give the compression results I got, or affect compression at all!! Basically he's telling me now that the motor is still good, and he even charged me $50/hr to look at it fo 3 hours. I'm going up there tommorow and he wants me to talk to the mechanic who is supposedely this ******* God with engines.

Thanks.

Marc

marcus219

any input..or answers to my question about vacc. lines and clogged cat causing low compression....im positive it woudnt..just would like some confirmation..

hypntyz7

Compression is a direct result of what goes on INSIDE the short block. Doesnt matter if you put no vacuum lines, 100 vacuum lines, EFI or carb on top of it. THe only variables are temperature of the engine/internals, amoutn of air being moved (throttle plates being open or not), and where/with what you take the measurement(lead/trail holes, what kind of tester).

I cant believe you let a junkyard man look at it.

SHoulda went with me for a few hundred more bucks, you wouldnt have this problem. Used motors are almost always a bad idea, unless their history is known.

marcus219

thanks Kevin..

The only reason I let them look at it was because I'm trying to get my money back remember. I payed $800 for it, and I need it back to buy my rebuild.

Thank you for confirming that for me...guy also told me that the high flow cat was bad for my engine..lol! I SHOULD have went with you in the first place, a long *** time ago when my engine blew. Not...one blew up on me, i bought one blown...and im down $800 bucks...**** **** **** **** **** ****.

hypntyz7

800 BUCKS!?!

Son of a BITCH man! Who pays $800 for a used JUNKYARD motor when you can get a rebuilt for $1000 plus shipping and core?

No offense, but you musta been

marcus219

thanks man...appreciate it...lol........I WAS ******* STUPID...i can say it. I had no other choice....i would have had to take out a loan to get a motor from you..b/c i had no way to get the extra couple hundred dollars. I'll defeintely learn from this..form now on im rebuilding myself or buying a rebuild. I had no idea whether the engine had 10k oil changes or anything...rotaries do not lilke to sit. I dont think im going to get a penny back from those bastards either...i could take em to court, but id end paying more in lawyer fees than i payed for the motor..so, now i have a good rebuild core for the future..but im still gonna take out a loan and buy a rebuild.

my poor 7...thats mine below..loooks pretty..but its doesnt go anywhere....i like to sit in it and pretend though...haha

marcus219

allright...please just confirm this again for me..vacc lines incorrectly hooked or or my cat being clogged. will not give me low compression. Compression is based internally by side seals, apex seals, corner seals, water seals, etc. The j-yard wanna be mechanic is trying to tell me that my compression would be good if the cat wasn't clogged and my vacc lines werent hooked up wrong. Im heading to the j-yard tommorow to battle with this guy, I'm 17 years old, and ofcourse hes not going to listen to a damn thing i say...Also the only thing i can think of as to why it hasn't built compression, is that the car was running so badly from crossed vacc lines that didnt run well enough to build compression. I dont see how this could happen, unless it was only running on 1 rotor....and remember my results were

rotor 1: 90-90-90
rotor 2: 30-30-60

So if anything it was only running on my front rotor, and those numbers are pretty low too. 85 psi is the min. in the FSM and 5psi isnt much of a wear limit and I wouldnt classify 90 as good running condition, as the motor is stated to be sold as on my warrany info. Please, Kevin, and gurus or knowlegeable guys, anything you can help me to argue with this guy with would be awsome. I guarentee you hasnt even checked to make sure my CAS is aligned or anything...
internal combustion engines (common knowledge) need spark, fuel, and comression. I aligned my CAS, i know i have fuel b/c my plugs were dripping with fuel, and well compression....my test shows that.

marcus219

also...this is how i did the compression test.

Disconnected CAS connector...removed EGI fuse. Removed both (upper) trailing spark plugs, removed the valve from the compression tester so it wouldnt hold pressure (whats the name of that thing, pressure hold or something), installed compression guage on rotor 1, had it at WOT and cranked engine for about 7 seconds. Same thing on rotor 2.

I just want to be sure that when i go there, i know ive done everything and its been done right. So when i go to bitchslap the bastard, when he wakes up...he wont be able to come at me with "you didnt do this" bs.

hypntyz7

YOu can check compression on a bare block with nothing on it. The intake ports are wide open, simulating having throttle plates open and allowing air to move through. Course the internal temperature will be low, so the numbers might be off <5psi either way, but the stuff ON the motor makes no difference to the compression IN the motor(block). What youre measuring is how efficient the engien internals are at moving and compressing air that goes inside there. Vascuum is a function of an engien running (the rotors spin, pulling air in through the intake, this forms vacuum, all vacuum nipples tap into the intake to get vacuum), so vacuum is what happens AFTER compression, not what GIVES compression. A clogged cat wouldnt have an effect on compression **when tested** because the engine doesnt move enough air while being tested (not running) for the cat to come into play. In theory you could block off the exhaust ports totally, and the engine would still make good compression numbers while being tested...the gas that would normally be expelled in the exhaust cycle would be carried around to the intake cycle adn would be released there, while the engine turns slowly enough that it can still have time to suck in fresh air. FOr that matter, during a test (not running) it doesnt matter which air is which, neither has been burned, neither is polluted or hot.