continued idle problems under load.

[WmWatt]

STI stands for "self test input" but that's all I can find from a search of the Internet and my collection of automtive books and manuals. I'd like to know what it does so will try a separate query in this forum.

[ryanprins13]

Any ideas why the STI connector is killing the engine when grounded. Supposedly it has to be grounded to check timing.

When grounded you go to base timing so you can set that. When not grounded the computer adjusts the timing to keep the car running.
Thats what i understand anyway. So your base timing is off far enough that it wont run without computer compensation.
Could be caused by a different problem though

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[ryanprins13]

12.6 on the battery, 14.38 coming out of alternator, 14.18 going to battery. occasionally the voltage going to the battery would drop to about 6 volts for a second then bounce back up.

That doesnt sound right. 12.6 with car off?
14.4 on cables with car running is good.
What was happening when it dropped to 6v?
You said you had a brand new battery and cables right?

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[bolokid]

When grounded you go to base timing so you can set that. When not grounded the computer adjusts the timing to keep the car running.
Thats what i understand anyway. So your base timing is off far enough that it wont run without computer compensation.
Could be caused by a different problem though

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Have you checked the timing belt positioning on the cam to be sure that it has not jumped a cog? I am with Ryan that the computer is compensating for something with the timing being amiss.

[WmWatt]

12.6v with a fully charged battery looks good here. with partially discharged battery voltage drops.

[cahman8]

makes since, I'm gonna check timing belt tonight.

[tooldude]

Timing belt theory makes sense. Still, you discovered a voltage anomaly. I wonder if voltage is getting around the system or dropping at the coil when running. Does the engine die with other electrical operation - lights, blower,rad fan? The regulator gets its reference voltage from the ignition switch. Could be a problem there or with fusible links, or maybe the spark is just very weak.

[cahman8]

There's no problems or change when running other electrical. Timing belt is lined up, looks good and has good tension.

[avitsefdrof]

Just a quick thought........I skimmed this thread and thought I'd throw this into it.....my Festy once in a while dies after coming to a stop....I'm pretty sure my issue is the dash pot.....its a small part on the linkage of the throttle that has a button that holds idle and gently brings it down.....you may be way beyond this already.

[tooldude]

It sounds like ISC is the problem, assuming B+ is getting to it. Have you tried increasing idle with the idle air screw?

[cahman8]

yea I tried messing with to idle air screw hoping to at least cheat for a little bit till I can figure it out. It help a little, but not much. It still wanted to dog pretty bad once put in gear or when turning the ac on during idle. It also seemed like the knock and ping got worse as it warmed up under load. I also swapped out anything I could find that was associated with the ignition from a good running car that I stripped out.

[cahman8]

Gonna try to post a video of a drive in my Festiva. Hopefully this will give a better idea of what's going on. Plus you get the bonus of a small tour of where I live, lol.
Sorry about the sideways camera.

[tooldude]

Did you increase or decrease idle air? One possibility of running at speed but not idle is a vacuum leak. I see it's automatic. There is a vacuum line from manifold to a vac diaphram on the trans. Check it and if good, cap off to check for leaking diaphram. Is manifold vacuum good & already checked for leaks? Engine ran well previously until this symptom, correct?

[tooldude]

Read through this again and the knocking pinging symptom is holding out. Seems like there must be an air leak or base timing is way off, or maybe both. Another possible air leak is in the brake booster.

[reddragon]

Have you checked all your earthing points?