kick7ca

I need some help please,
My car is 1 gremlin away from running perfect, and I just can't figure it out which is why I've left it with the dude that installed the motor in hopes he can find it, that's costing me $$ so please help,

Here's the specifics,
88TII, 40KM on mazda canada motor
no mods
new plugs
new wires
new grounds
factory exhuast system

Under boost the ignition is off slightly (or something is off) and it's low on power, this happens 4/5 times, 1/5 times it runs perfect and is faster than stink.

I had him check the timing, he said it's good. He suggested that somehow the ignition was breaking down under boost.

I'm not sure how else to describe the symptom, it just doesn't sound right under boost (and power is low). It has kind of a rushing air sound, and the exhust sounds like a jet - afterburn? I suspect it's not igniting all the fuel. Otherwise, the engine starts and runs well, but if it doesn't run perfect I figure what's the point of owning it.

I'd really appreciate some input on this, I have to solve it or I'm gonna sell.
Thanks guys

Wompa164

iTrader: (4)

I'd actually like to know this too.

I'm heavily modded, and after about 5.5-5.8krpms, I can feel the power just sort of 'drop off'. I don't know if it's my turbos just running out of efficiency, but could ignition break up be part of this?

I guess I'll just have to lug it to a dyno soon.

1987RX7guy

iTrader: (3)

I am not an expert but I want to try to help here.

Have the coils been tested?

Icemark

1st, I would be looking at voltage and ground at the coils, and make sure the exhaust pipe has it's ground straps.

2nd I would be looking at the switching actuator on the turbo to make sure it is not sticking.

kick7ca

are you referring to the twin scroll actuator?

HAILERS

After making sure the twin scroll actuator is working along with its solenoid (Green switching actuator controls it at 2800 rpm).........then make sure the throttle plates are opening each and every time. It's not the primary throttle plates that I'm refering to, its the secondary one. The outboard ones. On a turbo they run on a black cam and have a *damper* that keeps them from opening instantly. Operate the throttle by hand while looking at them> make sure they open each and every time. Take the intercooler off to see the linkage better. You won't be able to see the plates themselves.

As for the switchg actuator at the bottom of the turbo, idle the engine Now pull the vacuum hose off while your idling. Watch the actuator to extend when the hose is off and retracts when put back on. No sticking allowed. Then go check the throttle plates/linkage/black cam/ damper.

RETed

It sounds like one or more coils are not firing.
Check the spark plugs and see if their color is uniform.
The trailings will be a little more "black", but if it's black and sotty, it's not a good sign.



-Ted

IRISHMAN

DUDE, MY **** DOES THE SAME FREAKIN THING. 1OUTA5 TIMES IT RUNS LIKE A SPOTTED *** APE BUT THE REST OF THE TIME IT DOES WHAT YOUR TALKIN ABOUT. I TOOK THE CAR TO PETTIT TO DYNO AFTER I PUT THE SAFC IN AND CAMERON SAID ''DUDE IT RUNS GOOD'' BUT YOUR ACTUATOR IS OPENING TOO EARLY OR SOMETHIN OF THAT NATURE. THE FIRST PULL WAS 245RWP AND IT HAD A BEAUTIFUL CLIMB WITH NO SPIKES THEN THE REST OF THE PULLS IT JUST PETERED OFF AT ABOUT 5000 AND LEVELED OUT. I ONLY PULLED 180RWP. I ALMOST DROVE THAT **** OFF IN LAKE OCHECHOBEE ON THE WAY HOME. IT RUNS BEST MOST OF THE TIME AFTER IT HAS RUN FOR A WHILE AND THEN SITS FOR ABOUT 30 THEN RESTARTED. THE POWER IS INCREDILBLE. GOTTA BE SOMETHIN STUPID. IF I FIGURE IT OUT I'LL LET YOU KNOW. PLEASE DO THE SAME.

Amur_

NA86RULZ

You can get banned for that.

HAILERS

Double throttle plates are not opening each and every time.

kick7ca

thanks guys this is good ammo to go at the problem..
the mechanic is already going to try new coils, and I'll tell him to check the double throttle plates.

HAILERS....would faulty double throttle plates create the symptom I've described? Wouldn't that be just like not being able to go full throttle?

As soon as I have a result I'll let you guys know. Should have it fixed in time for the snow lol

More input welcome, please.

Icemark

The coils seldom fail, and I suspect that new ones will be a waste of money.

He needs to be checking the mounting, voltage and ground at the coils, not replacing them.

kick7ca

yeah he said he checked the impeadence on the coils, then said he was going to try coils with a "different frequency"....whatever that means.

Could the coils be firing wrong due to problems with:
knock control?
boost sensor?
computer?
crank angle sensor?

I feel helpless not having the car. I hope this guy knows what he's doing. I'll mention all this when I talk to him today.

thanks

Icemark

If the coils have the correct resistance, then they are fine.

What makes you think the coils are not firing?

I think he is lost, if he is barking up that tree.

None of those things you mention will have an intermittent failure as you describe.

Has he even checked engine error codes yet???

1987RX7guy

iTrader: (3)

One of my coil's the trailing died only on one side!! I just want to input this. The 2 side of the trailing coil went limp and didn't fire at all.

cbrock

iTrader: (1)

Could also be hitting fuel cut from the vac line to the boost sensor being replaced w/o the "pill" reducer.

kick7ca

thanks, but the "pill" is there.

Icemark, the mechanic mentioned he thought it was ignition. I agreed, as it seemed to make sense - low power, funny sound, possible afterburn in exhaust, + my plugs usually get black pretty quick.

However, HAILERS suggested the double throttle plates, can you second that?

thanks for all your help, I'm not giving up on this thing.

cbrock

iTrader: (1)

could very well be the second throttle plates. if those things get jammed then you'll never hit WOT. I don't know what the computer is seeing...perhaps you'll still hit 100% on the TPS and all of a sudden be running really rich as it does the throttle tip in enrichments. I assume you back off it after it hiccups and what not? But from what you say, for sure your problem is intermittent and probably not a HUGE problem. You only have 2 things for the motor....fuel and spark...obviously you're not getting one of the two. Check your fuel filter or pump lately?
Grounds?
Plugs/Wires?

Start with the cheap stuff first.

kick7ca

I spoke with the mechanic...
He's placed my car on the "back burner".
He thinks the problem is with ignition which is also causing my bad idle (I didn't think it was that bad), so he's going after the idle first, in hopes this will also solve the intermitent power issue. He keeps talking about the coils. I'm at $75 labor thus far.

cbrock

iTrader: (1)

For that much you could get a used set of coils, do the testing yourself and get a case of beer.

kick7ca

I just bought a 535i 5 spd which is occupying my garage time, so to me it's worth a couple hundred bucks to have this guy look it over and fix it right. Provided it's no more than that. I don't think I have the time, patients or experience to solve this one properly. However, I still don't want to take it up the pooper by the mechanic. I'm pretty sure he honest though.

trainwreck517

iTrader: (1)

Maybe Cats are clogged not allowing enough flow to boost?

Digi7ech

iTrader: (1)

ROFL you said Spotted *** ape!

Icemark

I don't understand why he has not even checked the error codes yet.

$75 in labor is too much if he doesn't know what he is doing.