Shobby

I'm having starting issues with my car.

In the morning it starts up right away no problem. But when I go to start it again later is has a hard time starting. If it sits for a few hours it will start okay. But if I step into a store or restaurant or whatever, it has a hard time starting. Always starts, but just has a hard struggle.

Any ideas what it could be?

djseven

iTrader: (56)

Sounds pretty classic of low compression. Usually when an engine is getting weak it needs to get down to around 70 degrees celcius before it wants to start. Start with a compression check on a warm engine. It will likely give you the answer you don't want but are looking for.

boosted414

iTrader: (30)

^^ that. after compression check post back with results.

Shobby

ugh thats terrible. I was hoping for a **** battery.
Can you get an accurate compression test with a regular guage and what not? I heard you need some fancy little device to get an accurate reading

94VRotary

iTrader: (6)

I saw few folks using sears compression tester.

rx7 SE

iTrader: (5)

Have you been premixing?

Also, I've used just a regular gauge in the past I bought from the local automotive parts store. Usually get around high 80-'s to low 90's on the FC and it starts up just fine. If you see 70's then I'd start making plans to freshen up the engine.

Do you know how many miles and what seals are in the engine?

Reno_NVFD

iTrader: (2)

http://www.rotaryresurrection.com/rotary%20pages/comp%20folder/comp.html

This may help you perform a compression check using a pistion tester. A rotary tester would be ideal though.

Shobby

I went out a picked up a basic tester from Princess Auto.
I pre mix and the engine is the stock engine with some mods sitting at 85000km no rebuild done

I'm going to go test it now, will post results later

Shobby

Okay, I am back with my results

I pulled the EGI fuse
I unplugged all 4 plug wires at the plug
Took out the 2 bottom plugs
Stuck the guage on one of them
Had the GF floor the gas pedal then crank it for a few seconds while I watched the gauge
I held the relief valve open
The gauge never cranked passed 50psi
I let go of relief valve
It peaked around 100psi

I am pretty sure that is okay from what I read like in the best 10 minutes. But I would love some experienced rotary guys to chime in

FD3Cam

If each face didnt get more than 50PSI id say rebuild time

RCCAZ 1

iTrader: (10)

It could also be leaky fuel injectors. If there's a Mazda dealership nearby I'd take it to them for a proper compression test. When warm, have you tried giving the engine a quick 1-2 second rollover, then pause and hit it again? Try that and see if it starts.

Shobby

Oooohh nooooo. That sucks. I was hoping for another 15K kms before rebuild

Shobby

I'll try that. I also installed new spark plugs while I was down there. Runs nicer now. I'm going to go for a drive and try doing that a few times. Thanks for the help guys

s2kguy17

iTrader: (5)

pm the gauge did you take out the little air thing on the end of it? I forgot what its called but looks like the same thing on the tire to let air out. Either way take it off and do a comp test that way.

Shobby

Schrader valve or something like that. I just held the relief valve open while the engine was cranking

FD3Cam

Id take it to a rotary shop and have them do a proper compression test and discuss some rebuild options. That compression seems super low to me

Shobby

I went for a pretty long drive. Started like a champ every time. Runs incredible smooth. Those new plugs made a huuuuge difference.

I'm going to compression test it again in a few days. Hopefully I was doing something wrong. If it is just as bad as it was I'm going to talk to Mazda about getting a proper test done.

motoron

sounds like classic flooding-do a major tuneup and have the tps voltage checked.

FD3Cam

Nice! Good to see its running well again...

djseven

iTrader: (56)

If the engine was warm and you saw 100 psi max and even bounces when holding the valve in, compression is not the issue. A 100psi engine will hot start fine, not super fast, but it will never leave you stranded. This is assuming all the faces are fairly close in compression.

Hopefully your plugs fixed the issue. If not, the next step would be to try to track down leaking injectors which is never easy if the car is sequential.

Shobby

The engine was definately warm. Both housings hit 100psi and the bounces were pretty even. I'm going to do another compression test this weekend hopefully and if the test shows the same then I think I will be okay.

I wouldnt even know where to start with injector issues. These rotaries and a whole new game to me