RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   The Rotary Gods aren't pleased with me (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/rotary-gods-arent-pleased-me-205678/)

snerd 07-15-03 05:20 PM

The Rotary Gods aren't pleased with me
 
I have been fighting with a stubborn project since October and I just can't seem to win.

I bought a beautiful Turbo II AE (not running due to a broken LIM), that had a freshly rebuilt engine. I thought that I would be able to get it running in about a month, but as project cars have a way of doing, this one roped me in to a long rebuild (interior refresh, new paint, body panels, engine parts, etc.)

So, jump forward to now and I'm finally ready to try to start her up. I've heard that rebuilds are a pain to start, so I didn't expect it to fire right away. Well, at first I wasn't getting spark because of loose grounds, then the battery died, then the starter died. After replacing the bad stuff I hoped it would start fairly easily. No dice.

I know that I have good spark (verified with a timing light), I have fuel (drained tank and filled with brand new gas, engine floods when trying to start, so it is getting to the chambers). I pulled the CAS and verified that timing is OK. The AFM is plugged in, etc. It still refused to fire at all (a few chugs and some exhaust while cranking, but not a full start).

As a last resort, I tried the poor man's compression test. I pulled a plug from each rotor and turned the engine by hand. The rear rotor gives me one loud "whoosh" and then two quiet ones. I know that is not a good sign, but the front is even worse. One good "whoosh", one quiet, and then the third is a strange sucking noise.

I'm going to pull the engine this week and try a real compression test with a tester. If there really is a leak in the front, it's time to crack the engine and see what's going on. I'm hoping that one of the apex or side seals is just stuck because the engine sat for so long.

Wish me luck and let me know if you guys have any suggestions!

Terrh 07-15-03 05:40 PM

you don't have to pull the engine to do a compression test, in fact, it's alot harder to do with the engine out than it is with the engine in.

One last thing to try before pulling the engine : put some ATF in the plug holes, and then pull start the car. Get it going about 40km/h, and put it in second gear. It WILL start with fuel + timing + compression, period.

Omegared 07-15-03 07:20 PM

I thought recent rebuilds need time to build up good compression? Maybe one of the guru's can help you out here. I'd hate to have to pull the engine when it may be something else. :confused:

hypntyz7 07-15-03 08:35 PM

True, new rebuilds can be a pain to start sometimes, and theyre somewhat low compression (as low as 65-85psi overall), but this doesnt sound normal at all. Even though the exact compression numbers might be low, there should be no discernable audible difference between the 6 apex seals. You either have some stuck seals, or you sent some pieces of debris through that engine at some point in time. Sounds as if it'll have to come apart.

But, since it's already installed, have somebody tow you around in 2nd gear at about 40mph. Sometimes the pure centrifugal force of high rpms (the starter turns at 250-300rpms max, so anywhere above that does a much better job) will actually slingshot the seals back into position allowing the engine to start working, and everything to start moving. IF debris did physical damage, there is no fixing that without a teardown. The only way to know is an inspection through the exhaust ports.


All times are GMT -5. The time now is 05:17 AM.


© 2024 MH Sub I, LLC dba Internet Brands