Miata Problem

[chuck schultz]

Idles ~2000 rpm with dips to 1500. Throttle application causes miss or stall. Top radiator (not heater) hose collapsed (may be pre-existing condition, although it ran mid-range all weekend.) Drove far enough to get off the trailer and across the lawn, now won't restart (turns over like crazy, just won't run.)

This after two days on track (around 200 miles) and then 2 days riding around on the trailer in the rain/minor flooding in Wilmington, NC before coming home.

At the track, it threw the power steering/air conditioning belt, but there were no other mechanical issues there.

Any guesses? I don't see any loose wires or hoses, there's gas in the tank, etc.

[bimmertech]

Well, here's my best guess based on the info provided. Bear in mind I'm no Miata specialist. The fact that you have a collapsed heater hose means that your coolant flow IS restricted. The miatas use a flow-through heater core with no regulating valve so it is not an isolated cooling circuit. The hose should be repaired asap. The best case scenario is that your idle control valve is acting up due to the lack of coolant as it uses an internal coolant passage to determine idle air requirements. It may or may not straighten out after the hose is replaced. Worst case would obviously be that the car has been overheated with a myriad of issues. Also, the heater hose and idle problem may not be related at all and you may just have a lean condition due to an air leak. Check your vacuum lines and air boot for leaks. If the heater hose collapsed due to oil contamination (or age), it's plausible that other rubber lines are in the same condition. If I were closer to Anniston I wouldn't mind looking at it for you. Hopefully someone familiar with girl cars can chime in soon.

[bimmertech]

I also believe the miata uses a liquid cooled intake manifold so a leaking manifold could introduce vacuum into the cooling system and cause a collapsed hose. Of course, this almost never happens.

[chuck schultz]

Whoops, I meant to say the top _radiator_ hose was collapsed. . .

[rodhx]

Hopefully someone familiar with girl cars can chime in soon.

In the midst of being helpful Casey just couldn't resist the opportunity to take a shot at our poor little cars. Said shot was likely aimed at our tires hoping he could slow some Miatas enough that he can catch them j/k

[TouringBubble]

Have you verified that there is not a vacuum leak? Are the fans activating when it's at temp?

[J2870]

Also did it throw any engine codes?

[chuck schultz]

One thing I need to check is that the air filter isn't filled with water from the wet weather in NC. . .

Have you verified that there is not a vacuum leak? Are the fans activating when it's at temp?

Don't have the tools to check for a leak, and the car didn't warm up in the 2 minutes or so after I unloaded it from the trailer. The fan was working at the track, Sunday.

Also did it throw any engine codes?

Did get a Check Engine light, which stayed off after a restart.

I guess I need to figure out how to get it back on the trailer and take it to somebody who can do some diagnostics. For now, it's off to Crow Mountain! I'll think about the Miata when I get back.

[edtype1]

What year Miata & engine size? Since it came off the trailer & died has it started back up? Check for spark, fuel & even broken timing belt?

[chuck schultz]

'92 B6 1.6, started once or twice after parking, then just starter noise.

Did have time today to discover that there's apparently no spark. That's weird after the fast, uneven idle. . .

To top things off, the ol' Camaro quit running, too. It has plenty of spark on all 3 coil packs. It's been threatening to not start for a while, but we were too busy keeping the wheels on the van, etc.

[zukitek]

check the timing belt Chuck. Could have a wallowed crank sprocket keyway. Bear in mind also that the fast idle valve requires the circulation of hot coolant to to heat the spring and close the passage to bypass air (just a guess on the idle speed thing)

[EWaugh]

I'm working on the new project at the depo so let me know if you need any help, i could swing by after work

[chuck schultz]

let me know if you need any help

Thanks.

We figured out the Miata problem, but I might need a hand, some time, pushing the Camaro up on the trailer. . .

[ZX3Focus]

We figured out the Miata problem, but I might need a hand, some time, pushing the Camaro up on the trailer. . .

The solution to the Miata problem was to drive a Camaro?

[EWaugh]

Or to just give the miata to his wife and take the camaro