Yep - 30degree weather, OEM fuel/turbo, a perf exhaust & downpipe.

4th gear - full boost - PING!!!!!! - sounded like someone hitting a tin can really hard.

I thought fuel cut would hit before it would ping.

The OEM boost gague rises EXTREEMLY fast all the way to 1 bar (usualy only 3/4 of the way up). Guess I'm getting some boost creep.

 

Do you happen to have an 89-91 Kouki model?&nbsp There's been owners who claims they can't hit fuel-cut on these cars...

Do you have an upgrade fuel pump????



-Ted

 

OEM ECU - that's what's strang about it, it's suppose to cut fuel.

I haven't put on a perf intake yet because the downpipe & exhaust upgrades cause 8PSI boost creeps - then imagine a perf intake (yowza).

I've been thinking of an aftermaret ECU & boost controller to keep the OEM setup in line.

Mazcare mentioned I should check the pills in the vacuum lines as if they're missing they might also be causing my deceleration harshness.

 

Remember, a boost controller can only raise boost, not lower it.

Deceleration harshness?&nbsp This could be a function of a bad TPS or bad ignition due to bad spark plugs or spark plug wires.




-Ted

 

RETed,

Mazcare's performed the 60K services & spark plug wire repalcements. Could be something in the ignition, but the manual mentions the dashpot and several other parts that control the deceleration as most likely cause. Of course the manual is only right 1/2 the time anyway

Basically if you let off the gas in gear the car should not jerk - with or without boost. It's most apparent in traffic in 2nd gear. Tap the gas, let off, tap the gas - should be smooth and not jerk.

Worse is 4th gear @ full bost & letting off - huge engine jerk.

Well the the body/drivetrain has 145K and the engine has 28K - so I'm not surpised on these minor annoyances. Just want to work through them Hope it's not related to having a downpipe though (ie less backpressure).

The manual recommends removing and checking certain pieces of the deceleration system, so I might do that after mazcare gets my other FC I just picked up in good shape (89 FC convertible).

Anyway I'm trying to get into repairing my own stuff - so any thoughs you might have on boost creep or deceleration would be great

Thanks

-- vaughnc

 

its was around 30-40 degrees today and i took the T2 out to run some errands...and i was hammering it! (ask vosko! haha) still no fuel cut...and no FCD. just one ported wastegate

 

Is this an 86-88 Zenki or 89-91 Kouki model?
If it's an early Zenki model, I'd blame the TPS.



-Ted

 

yeah I've had porting the wastegage in the back of my mind too, but I can't get all my ducks in a row

1) get micky mouse gague pod in from Japan 2) install a decent boost gague and see for myself what PSI I'm running 3) fix boost creep 4) fix deceleration

And now I've thrown another FC into the mix

And let's not forget the vibration in the steering wheel & getting a perfect allignment as well. I've been eyeing that sweet engine brace/strut tower brace/torque brace they have to help with some of the vibration.

What's funny - mazda nor mazcare offers an engine balance - what's up with that ??

all minor stuff I know.

 

91 Turbo II

.... note to self - look up Zenki and Kouki ....

 

hey vaughn...the deceleration might be the TPS, but it also might be something to do wtih the throttle cable hanging up. is it in the right position? after i put in my TPS the car was good to go again...but had a kind of rough decel and a "mechanical delay" between letting off and pushing the gas pedal. last night i had the chance to fuss with it. i looked and saw the throttle cable was tucked under some **** where it should have more play. i adjust the 2 hangers for it and viola...today i took it for a spin and it was great. the idle at that point was kinda low i think due to the readjustment of the cable...so i just turned the screw on the BAC valve a bit and now it idles perfect...right at 750.

i was all about adjusting the TPS...but it seems as if this solved my problem. i've heard mixed feelings on the 89-91 TPS...some say its self adjusting...others say no, you still have to turn the screw. oh well...will we ever know??? lol

 

There are a lot of different ways to differentiate the model years - I use the Zenki/Kouki designation just as the Japanese do.

Zenki literally means "before".
Kouki literally means "after".
This designates the model change between 1988 and 1989.
The Aussies use Series IV/Series V - same smell.




-Ted

 

Erik,

I'll take a look. The TIIs have the throttle cable going around the intercooler and back. I believe the holding bracket was pretty tight last time I check though.

 

On my 88 n/a, in low gears, it does this.. It's horrible in 1st gear in traffic.. really throws you around.. Tho, my TPS changes very linearly...no spikes or anything.

-Tesla

 

Might be as simple as a misadjusted TPS...



-Ted

 

i think i remember you have the mariah intake...what exhaust do you have?

 

mine isn't really smoth in any gear leting off. I just try and slowley let off as smooth as I can. could be anything from engine, tranny, diff mounts to worn U-jonts or halfshafts. to engine stuff.

these cars are old... they are not going to be perfect. I just learn to live with it.

 

Erik,

Haven't put it on yet as I know I'm already getting boost creap from the perf exhaust & cat.

 

cool, yeah i was just wondering what kind of exhaust u got?

 

it's machine shop made with some perf exhaut, downpipe, & glass pack mufflers. came with the car and it does a decent job.

 

Forget buying a boost controller.
Just use VaughnC Boost Controller Profec A! aka yer right foot.
Hahaha
Heck! its free!

 

How old are your plugs? Mine developed a ping in the last week. I was thinking I got some bad gas. I raised the octane but it didn't help. I retarded the timing 6 deg's and it still didn't help and it also started missing and backfiring. It scared the **** out of me and I figured it was engine time. Worn Plugs! Mine only had a few thous. miles but they were well worn. Nice and tan/brown but way worn down. I put some new ones in tonight and voila! I also went w/ 4 BUR9EQ's. It had 7's before.

Runs great now. Wish the track was still open, I ran a 13.19 @ 104 on these plugs last month.

Scott