No power from stand still

speed · Postby **speed** » Fri Oct 17, 2014 5:18 pm

I wouldn't have bothered looking at the cat but like you say you can cross it off the list.
So how about TPS and CAS?

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93_Clubman · Postby **93_Clubman** » Sat Oct 18, 2014 12:45 pm

jerdes wrote:1990 NA6 - over the past two weeks I've noticed that there is hardly any power whatsoever from a stand still. At the lights it takes about 20 seconds at full throttle to get to 3000rpm in first, even worse up a slight incline. However, downhill, the car takes off fine. Also, once I get a run up, the car runs okay, although it could probably run a little bit better due to a few flat spots here and there.

Does it rev normally when stationary in neutral?
Similarly, what does the timing light show in relation to ignition timing when you rev (but this time don't short the GND and TEN pins on the diag connector)?
Something else to check is the accelerator pedal assembly, as the NA6 is prone to cracking where it attaches near its top to the firewall, which eventually results in depressing the pedal with lessening effect.

Re basic SNC fix parts (key & bolt) - probably easiest to just go to Mazda first, if they still stock them. If you also need a new pulley then maybe MX5Parts UK, or similar, might be more competitive.

jerdes · Postby **jerdes** » Sat Oct 18, 2014 1:02 pm

speed wrote:I wouldn't have bothered looking at the cat but like you say you can cross it off the list.
So how about TPS and CAS?

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I unplugged the tps and the car seemed to worse at idle, so I assume that's not the problem. My driveway is quite steep and I struggled to get the car up into the garage so I kind of don't want to risk having it stuck out on the road haha

I also don't have a spare cas or anything sitting around nor could find any real information on how to test it. The intake timing seemed okay though so would that kind of rule it out? I don't know haha

93_Clubman wrote:
jerdes wrote:1990 NA6 - over the past two weeks I've noticed that there is hardly any power whatsoever from a stand still. At the lights it takes about 20 seconds at full throttle to get to 3000rpm in first, even worse up a slight incline. However, downhill, the car takes off fine. Also, once I get a run up, the car runs okay, although it could probably run a little bit better due to a few flat spots here and there.

Does it rev normally when stationary in neutral?
Similarly, what does the timing light show in relation to ignition timing when you rev (but this time don't short the GND and TEN pins on the diag connector)?
Something else to check is the accelerator pedal assembly, as the NA6 is prone to cracking where it attaches near its top to the firewall, which eventually results in depressing the pedal with lessening effect.

Re basic SNC fix parts (key & bolt) - probably easiest to just go to Mazda first, if they still stock them. If you also need a new pulley then maybe MX5Parts UK, or similar, might be more competitive.

To me, the car revs normally in neutral. It does have a little bit of a popping noise coming from the headers on deceleration after a good spurt of the throttle. I assume that's pretty normal though?

I'll check the timing during revs to see what happens.

I'll also have to look at the pedal assembly. On that point though, I did notice my throttle cable has a lot of slack in it. It's pretty worn out and it's set at the tightest. At full depress of the pedal it opens the throttle body all the way so I didn't think much of it.

gslender · Postby **gslender** » Sat Oct 18, 2014 2:27 pm

Timing cams could be out by a tooth if the belt was replaced at sometime in the past. You can't tell unless you remove the rocker cover.

speed · Postby **speed** » Sun Oct 19, 2014 10:34 am

When you say the throttle cable has slack, full throttle on pedal should = fully open butterfly in tb.
Have someone press the pedal to floor whilst you check.
Tps adjust us done by rotating not by unplugging however I think 93_clubman is on to something.

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93_Clubman · Postby **93_Clubman** » Sun Oct 19, 2014 11:43 am

Jerdes, if you're at it today, it would also be worth checking the rear brakes aren't binding - rear pside is usually the culprit on the NA. The adjuster on the rear caliper for the handbrake eventually siezes & then when handbrake is applied rear pside (usually) stays locked to some extent. Simplest way to check is does it roll easily when pushed a short distance on a flat surface.

jerdes · Postby **jerdes** » Sun Nov 30, 2014 7:21 pm

okay.. so after having the mx5 sit in the garage for quite some time, I finally got off my ass and decided to open the engine up.

When removing the timing covers, I noticed the gaskets were crap and there was about a 2cm thick casing of oil sludge around the motor.. Definitely needs a good degreasing.

Finally got to the keyway and there were no real problems at all with removing it, which surprised me. I think it's safe to say that I found the problem though.. How do you guys think it looks? I thought it was going to look a lot worse.