VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

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AJS
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Car Model: MK2 CLi 8V Jetta

VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by AJS »

Hi I'm new at this so here it goes. Every time that I accelerate the vehicle from 3500 rpm to 5500 rpm it pings very loud at times in all the gears even when driving at 120 kmph and accelerate to 140 or 160 kmph. I replaced injectors because of misfire when cold and standing for awhile. I tuned and set the fuel system (k jetronic) myself and learn a lot from it. Setup as it is now. VW Jetta 1.8 8v CLI EV engine stock standard, K Jetronic system, Fuel pressure. System pressure 5.4 bar. control pressure 2.2 bar cold / 3.65 bar hot. Timing 5-6 degree idle 890 rpm CO% 1.5. Spark plugs NGK BP6es 0.8 gap. 350000 km engine never been open. 3rd owner and vehicle still going strong when not pining. Any info will be helpful.
AJS
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Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by AJS »

Hi me again. It pings more when hot. Please any advice
VAG Fan
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Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by VAG Fan »

When did the pinging start - what was the last thing you did before that?

What do you mean by "tuned and set the fuel system myself"?
... Did you compare the four lines for equal metering, i.e. same quantity injected on all four lines, at all angles of the air flap?
... Is the air flap unrestricted?
... Did you check that the air/fuel ratio is correct throughout the whole rev and engine load range? (E.g. exhaust gas tester on a dyno.) CO is only adjusted for idle, but may be incorrect at load.

Did you check that the system pressure and control pressure are actually maintained when the engine is under load? If not, the fuel pump may be failing.

Is the valve timing correct?

Does the distributor have centrifugal and vacuum advance, and are both within spec?
Mark R.
- - - - - - - - - -
2004 VW Golf TDI, type 1J, AHF, 317k (2016-current) --- daily
1990 VW Fox, type 16, HM, 304k (2005-current) --- spare runaround
Previous:
1992 Audi 500 SE, type C4, AAR (2001-2020) --- nice while it lasted
1983 VW Golf GTS, type 17, FR (1992-2005) --- most fun car I've ever had
1978 Audi 100 GLS 5E, type 43, WC (1991-92) --- died in the side of a Rekord who cut me off
- - - - - - - - - -
AJS
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Car Model: MK2 CLi 8V Jetta

Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by AJS »

Hi VAG. only parts that i have change was the injectors but that should not affect anything and that could be where the pinging started from. i tried another distributor with same part nr. tune and set myself means set everything according to the book values, made my own fuel pressure gauge too adjust fuel pressure and so on. their is no restriction of any sorts. Valve timing is spot on, even tried another camshaft (G camshaft) and sprocket. No equal metering of four lines done yet, will do it during the week. Which is the best way to adjust the metering head if out of specs. I was even thinking of installing a kr engine knock control ecu to prevent the pinging and would be a nice project to try out as well Thanks for the reply Jakes
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Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by VAG Fan »

Remember to check and compare injection quantities at low load (idle), mid-load, and almost full load.

I would only make changes on the metering head to get all 4 injection quantities equal. If they are already equal, then chances are that you're sitting with a different problem, e.g. unmetered air being drawn into the system. In this case, I would first look for all other potential air-fuel-ratio problems, and only work on the metering head itself if you put the car on the dyno and gas analyser.

But if you DO have unequal injection quantities, then I would start by inter-changing the injectors between the line with the lowest quantity and the one with the highest quantity.
1) If the injection quantities move together with the injectors, then you know that the injectors are no longer good, and you need to renew them.
2) If the injection quantities remain more or less as they were before, then the problem is in the metering head, and I would proceed as follows:

Take an extended test drive with various loads and engine speeds, and then compare the metering quantities with the visual appearance of the corresponding spark plugs.
3) If there are one or two fuel lines that inject less than the others, and the corresponding spark plugs look to lean (clean, glassy or white deposit), then adjust the quantity on those lines upwards until they inject the same as the others.
4) Similarly, if there are one or two lines injecting too much and the corresponding plugs look too rich, then reduce the injection quantities until all 4 are equal.

The injection quantities are adjusted, to my knowledge, by using a shimming screw on each injection outlet port. On my Audi's KE-Jetronic, those screws are on the underside of the metering head. But I think on the K-jet they are on the top, so you don't need to remove the head to make adjustments. The shimming screws are normally hidden underneath a cover screw, IIRC.

Whatever you do, work in small steps and keep an exact diary of the changes you make.
Mark R.
- - - - - - - - - -
2004 VW Golf TDI, type 1J, AHF, 317k (2016-current) --- daily
1990 VW Fox, type 16, HM, 304k (2005-current) --- spare runaround
Previous:
1992 Audi 500 SE, type C4, AAR (2001-2020) --- nice while it lasted
1983 VW Golf GTS, type 17, FR (1992-2005) --- most fun car I've ever had
1978 Audi 100 GLS 5E, type 43, WC (1991-92) --- died in the side of a Rekord who cut me off
- - - - - - - - - -
AJS
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Car Model: MK2 CLi 8V Jetta

Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by AJS »

Hi Lieutenant
Okay here it goes
All injectors are spraying equal but very coarse not a fine miste as I think it should spray. I clean the injectors with injector cleanner and some heavy duty engine cleaner through a high fuel pressure pump and back wash as well
in opposite direction and a lot of black dirt came out of the injectors
It looks better but not a fine mist as i thought i should be
Here are the part nr of injectors
Old: 0 437 502 043 vw 035 133 551 F
In engine now: 0 437 502 032 vw 035 133 551 C
Can it leak air past the air shroud circuit at any change because those seals has never been replaced at all and how can I test the circuit.
Thanks for advice Lieutenant
Jakes
AJS
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Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by AJS »

I think the injectors are from the vw 2.5 kombi
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Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by panic-mechanic »

you need to check air/fuel ratio and timing on a dyno. anything else is kind of guessing even if the control pressuresare according to the book.
if you put different injectoes in they might be under fuelling.
Stephan van Tonder - Jhb - Putfontein Benoni
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AJS
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Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by AJS »

Hi me again

Been gone for a while and time got hold of me but here it goes
as my car is still pinging it started to misfire on one cylinder when engine hot but when cold the misfire is gone so I
check spark plugs and no fault, so I did further diagnoses, connected the gas tester and every time it misfire the CO levels will rise to 3.0% and found that nr1 cylinder misfire so the only cause for misfire could be injector,
so off I went GW in Strand to buy injectors, well I took one for now (R520)each (budget short) and went home and replace nr. 1 injector
and straight away the misfire was gone and CO back to normal, pinging is a bit less I think and responding is also better, so each month I will buy one injector and replace them all.

That is all for now

Cheers for now ;-)
AJS
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Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by AJS »

Hi me again

I want info on exhaust of my vw jetta, the engine is still standard, manifold is standard as well, my question is should I go single silencer box or duel silencer and must not be noisy as well. want to keep it standard as well

Cheers for now
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Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by PapaJo »

AJS wrote: Mon Dec 30, 2019 9:08 pm Hi me again

I want info on exhaust of my vw jetta, the engine is still standard, manifold is standard as well, my question is should I go single silencer box or duel silencer and must not be noisy as well. want to keep it standard as well

Cheers for now
If you want it not to be noisy, fit a 2 box silencer system.
AJS
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Re: VW jetta mk2 1.8 8v CLI 1989 pining (knock???)

Post by AJS »

Hi
Thanx PapaJo

Now ever since replaced the one injector that was faulty, the car became a beast, I mean at 130-140 kmph on highway and foot get a bit heavy, it feels
like a turbo kicking in at the minute and starts to see 180 kmph with ease. I never realized that a vw jetta 1.8 8v k jetronic (stock standard) can become a beast like that, its totally a different car now (I like it ;-) )
When the other new injectors are fitted, I have to put a brick behind acc pedal to prevent me from getting speeding fine (hehehehe)
What I wanna say is that the injectors is the main reason for pinging and knocking and so on

Thats all for now cheers
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