CE1 DigiII strange running issues. Just a little guidance, please.

[4RingsRuleALL]

Just picked up an '88 Jetta GL with 97k. CE1 DigiII manual. I've owned the car since monday and have been dealing with annoying issues since the start.

It has several running issues that are driving me nuts.

New parts and fixes.

New BLUE CTS(I think its supposed to be white?)
New cap, rotor and wires as well as being timed.
I think the plugs are new but are Autolites
I just redid all the grounds. From Positive terminal to starter and to the Alt.
New cable from negative terminal to trans, valve cover to intake mani and from there to the firewall As well as the body ground next to the battery and put new ends on all the wires attached to the terminals.

Annoying problems.

It idles at 1800 and I've never seen it idle below 1200.
It feels like its missing or hesitating at neutral throttle(just holding an rpm while driving)
It just began spark knocking yesterday .
The power feels very high in the rpm band with very little TQ at lower rpms. (Have trouble accelerating in 5th on slight grades)
It also doesn't start too smoothly, no dieseling when its shut off but it just doesn't start like a DigiII car should.

PLEASE give me input on this. Ive searched around and haven't found any posts that address all my problems at once while including my grounding fix.

I suspect a vacuum leak, the wrong CTS, improper timing and a malfunctioning ISV. I dont think the ECU is acting up, but I havnt gotten in that far.

[4RingsRuleALL]

Anyone? Anyone? The tariff bill?

[4RingsRuleALL]

Found a worn O-ring on the idle set screw. Replaced that and lowered the idle to 1k. Still does the bucking/hesitation/misfire though.

[randi dub]

does it smell like alot of fuel is not being burnt off like its running rich, at night look under the car to see if the cat is glowing red if so your running rich and its most likely the computer , you need to be really careful with the digi's when doing electrical work allways disconect the battery so you do not fry the cpu

[4RingsRuleALL]

I know how easy it is to fry a digi2 cpu lol done it a couple times on accident. It does seem to run a tad rich, but its usually only at start up. Although I JUST went out to the car to start it and let it get a warmth in it before I take it out. Had a lot of trouble staying running on a cold start in 35degree weather. I'm going right now to do the timing on it and replace the knock sensor. So Ill post up after that. Thank you fro the response. If this doesn't fix it, my next move was to search for vac leaks and then try different computers.

[4RingsRuleALL]

ok, set the base timing to 5degrees btdc and checked my advance. Adjusted the idle back down and changed the knock sensor. Found a unclamped hose on the intake manifold. It is definitely running better but its still doing that phantom hesitation thing. So I suppose I should start testing the ecu and make sure its working correctly. Im hoping to rewrite this so its a simple DIY writeup for beginners with digi2. Ive had to relearn a lot of this and couldnt find a complete step by step guide on how to properly check things and in the right order.

Does ANYONE have any ideas about this hesitation/misfiring thing, its only doing it when im transitioning on and off the throttle or try to hold a rpm lower in the range(35mph in 5th)

[EuroTrashin]

Yeah, I'm having the same issues. Except i had my car not hold idle at all, replaced the ISV and now it sits at RPM 1500 instead of the 900 it did, and it still chokes when on idle, but the RPMs are pretty high now, replaced all most all the same things.
I've tried to locate a vacuum leak, but nothing, then cleaning the MAF made the idle worse for some reason. I hate DIGI II, owned it for less than two weeks now, and already learned a lot, but still clueless when it comes to fixing it properly.

[4RingsRuleALL]

Do you have Bentely Manual? I learned everything from reading one of those. Everything Ive done to fix my problems are from the book. Try doing the timing and replacing the grounds. once your timing is set, adjust the idle, then recheck the timing adn back and forth til your are 900. Get a AMmeter and Ohm some stuff out. Try spraying carb cleaner on the rubber connections, put your hand on the hoses and wiggle, if they move, replace them

[EuroTrashin]

Yeah mines all good now, changing the CAT also made a difference, thats what ended up solving my problem. No vacumm leaks tho.

[4RingsRuleALL]

A little teflon tape on the threads will keep your idle screw from backing out if the o-ring is bad. I still have the breaking up issue. It seems to be less bad when the car has 93 in ti opposed to 87 though. It has the correct copper plugs and new ign bits.

[threecaster]

My MKII Jetta was narcoleptic for a while, turns out the B+ from the fuse block was pulling out of the connector. I actually wired a VDC meter directly to my CPU supply so I can be sure it's getting good juice.

"No NO! Less Cranky! More Starty!"

Grounds are excellent work BTW.

You could try cleaning your idle stabilizer with some throttle body cleaner, make sure it's lines are tight, sans cracks in the rubbers.

Timing, Vacuume Leaks, the O-ring onthe Idle Adjust...

Did the knock sensor fix your pinging?

I will frequently reset my Digi CPU when I've been adjusting things...
(Unplug Blue coolant sensor, rev above 3K rpms 3 times, turn off, reconnect...)

Midrange hesitation could be the fuel pressure regulator.

[4RingsRuleALL]

I need to look at my FPR then

[4RingsRuleALL]

So, my O2 sensor ended up being busted, the ceremic at the connecter side snapped off. Havnt replaced it, but since i stopped it from arching, it runs REALLY well. Beat a couple MK4 12valve VR6s at H20i this year lol