Car starts/idle when cold, as soon as warm it dies
 

Here's the deal...

My engine blew. Mazda took it and was going to warranty it. Long story short 2 engines later (the first one they got came with zero compression on the front rotor from the rebuilder) I am in possession of a broken rx8.

They have told me they are unwilling to work on my car because I have done the TB mod, have the fan mod from Mazsport (or whoever, can't remember), and an AEM cold air intake. They also aren't happy with my exhaust but said they don't think that has any correlation.

The new engine is in the car and it has good compression. When the car is cold it starts up perfectly and drives great. As soon as it warms up it continues to drive just fine but as soon as I take my foot off the gas it dies. Then almost every single time it will not restart (I've only gotten it to restart once after dying). They told me they will not continue to diagnose/fix the problem until the intake is stock and the TB mod is undone. I'm contacting a lawyer for this warranty issue but that's another story.

Are there any other common problems I can check with this issue? There are no vacuum leaks, I know this for sure (been over the whole car, checked with brake fluid, etc). From searching I found fuel pump, spark plugs, coils could be the issue. What are ways to check these? What are some other possibilities?

I have a good amount of tools and knowledge for testing stuff, I just need to know what to check.

Any input is greatly appreciated!

Sounds like the typical compression loss scenario.. metals expand when hot so you're not completely sealing at that point and your compression sucks!

This is the second new engine they got from the Mazda rebuilders. Had this issue from day one, zero miles, all comp tests were fine.

I'm hoping that Mazda didn't get two faulty engines in a row from the Mazda rebuilders, otherwise there's a much bigger issue at hand.

Gotta be a code getting thrown when it dies and won't start... check the engine codes as the first step.

And throw the intake and throttle body hose back on so they can rule that out. That is probably throwing off any mechanics/ techs that are working on it.

After the ECU is re-set you will have that problem.

You have to drive a few cycles before the ECU will learn to keep it idling.

After a couple of days it should be fine. If not let us know.

Never mind, a new reason to hate Mazda.

Today I spent 1.5 hrs of diagnostic time, which included going to the parts store, found where they didn't hook up something properly, car runs perfect now. It starts cold and hot, doesn't die when hot, doesn't die at idle, idle is smooth and at the right rpm. Long story short it was a vacuum leak (uncapped nipple) and a hose that wasn't hooked up.

I drove it to my Mazda dealership and pulled it into the breezeway after I confirmed everything was good. The service manager and general manager were there and saw me pull in. Basically their jaws dropped. I got out and they asked me how I got it running. I popped the hood and showed them where it went wrong. They had 40 hours of diagnostic time documented by their tech (this doesn't include the engine replacement apparently) and they couldn't get it running and didn't notice this oversight. They brought the tech out to show it to him and promptly started yelling at him in front of me. Normally I would say that was completely inappropriate since I am the customer, but just yesterday I was the one being yelled at and they were telling me I needed to shut up because I didn't know anything about these cars and to leave it to the "professionals."

They had my car for over a month, yelled at me, told me I was dumb, told me it was all my fault, and forced me to take a non-running car home. They spent a good 20 minutes apologizing to me and gave me a $200 gift certificate for their parts department to use as I please.

Just glad to have my car back with a brand new engine. The more I drive it the better the idle gets and the smoother it drives. Gotta love the break-in process....

glad it is going good now, what did they not connect?

who found the problem?

beers :beer:

They left one vac nipple exposed (not capped) and a hose not hooked up properly, both on the intake manifold.

Basically because they said my mods "caused" the engine failure and made it difficult for them to diagnose the problem :rolleyes: after the new engine was in, I had to take it. They forced me to give the rental back and told me I had to have my car towed out of their service area otherwise they'd have it impounded. I did try to drive it home hoping I could make it without coming to a stop, since it only died when stopped, but half way home I failed and had to have it towed the rest of the way.

So I spent my 1.5 hrs this Saturday morning finding the issue, fixing it, and driving my car back to Mazda to show them.

Plus I got to talk to all of their boss and tell him how I was treated, hence the gift certificate.

i bet you i know what nipple it was!

beers :beer:

Probably. It was in plain sight (granted on the under portion of the manifold). Not sure how that tech could've missed it...

Wow, what a bunch of losers....Nice job on finding the problem and making them look like idiots!! Dealers are so quick to blame mods....like an intake :uhh: and it ends up being their idiot techs that are the problem.

ahh... I was going to guess that but they usually run rough when cold dur to the leak.

glad they figured it out

They didn't figure it out, they're idiots.

So who did? lol anyway as for some free oil changes or youll kill someone lol

I did. They forced me to take it in a non-running state and I spent a little under 2 hours finding a vac leak and a line they didn't hook up.

So how about an update?

Car ran perfect for about 40 miles then suddenly died at a stop light. Would not restart, not even close. Let it cool all the way down and tried to start again about 4 hours later, and it wasn't even getting close to firing up.

I contacted a lawyer and had him call the dealership to threaten legal action unless they upheld their duties with the warranty. The car is now back at the dealership and they're once again dealing with the problem. Whatever originally caused the failure was still there I think, which is why it just quit on me again. So Mazda has it back and I have a free rental from them.

I'm really starting to lose faith in the Renesis and Mazda in general. And I found out Mazda's old engine rebuilders were from Ford, just recently did this change :(

I prefer the older style 13B....

^the renesis is a good engine if maintained properly....as far as the Mazda techs at your dealership as well as others....just plain suck

Oil changes every 2-3k miles, every time I refilled my gas I checked the oil level, treated it well the whole time, redlined it a couple times a day once fully warmed to clean it out, etc.

And after all that I had the engine pop after 28k miles. Then the first engine Mazda put into my car as a replacement popped after 10 minutes of idling. Maybe it's my bad luck, who knows. But there have definitely been more Renesis engines dying with lower miles than with the 80's and 90's 13B, at least from what I've seen. It might not necessarily be the engine, though, just the supporting components. Hard to tell.

I'm not trying to dog the car, I love my RX8. But with all the issues I've seen and amount of premature blown engines, I just have some skepticism. My old 88 RX7 seemed much more tolerable.

And my car is on engine number 4.

Apparently when my car stalled at a stop it had lost all compression in the rear rotor, after 30 miles. So they ordered another engine for me.

They have no idea what keeps blowing the engine. This is getting interesting.