Question: 1.0 37kW warm/hot vs cold Engine

[telbert twang]

Hi,

I have questions about 1999 AER 1.0 37kW 5D 6N1 (which I firstly got as a temporary replacement car, but am actually starting to like it much, specially at city rides - thinking of getting it totally fixed and refreshed step buy step) warm/hot vs cold engine :

It starts very well and after some quick warmup gets pretty lively and is fun to drive... But after getting warm/hot, it gets a bit lazy. The overall acceleration gets worse, at some rpm spots (between 2300 and 3100) it sometimes gives some light "hitches", kind of revs rough, resulting weaker dynamics than it could do. ... While giving it gas on neutral and idle , it kind of lightly "sneezes" before starting to rev up and is weak/nam on take off (gets better when gaines some rpm) . With hot engine, it tends to give some valve lifter tick as well (which is not present with colder engine). The car has done about 145000 miles, has quite fresh plugs, wires, brand new distributor rotor (the previous had been burned out and showed almost 100kΩ resistance/impedance, for unknown reason )... Oil replaced about 1300 miles ago. Fresh air filter . At first it sometimes used to go give an aural "beep" and oil pressure warning sign with hot engine and lower rpm, but not anymore after oil and filter change (i suspect a faulty oil filter on that). Timing belt replaced 65k miles ago (new one waiting in box). I feel that the engine gets pretty hot as well (specially now, in summer ) - may do cooler ...

So, what do you reckon?

- Poor/lean mixture ? ( Is there a way to adjust it "DIY" )?
- Poor oil flow , pressure, (worn/ clogged oil pump ) ?
- Something wrong with the spark ?
- In addition - what about the tubing (2pcs, come in under the air filter box) - do they adjust mixture cold start/run vs hot engine? May they get clogged, leaking , installed wrongly?


Some pics about plugs and the tubing under/inside the air filter box:
https://onedrive.live.com/?authkey=%21A ... B7B179F712

Many many thanks in advance for any consultancy!
Rgds,
TT

[telbert twang]

... I think I am going nuts The car drives me crazy. While not yet totally warmed up, it goes like a small angry wasp. After the temp pointer positiones exactly vertical, it tends to get lazy - weakening dynamics on low rpm ( takeoff ); somewhere between 2300 and 3200 those weird gently perceptible letargic "judder/jerkiness spots" ... With hot engine, while stepping the pedal to the metal, it may give a "drag" , instead of acceleration... And, sometimes , there is no problem at all ! Starting to think about checking the throttle body, after some reading ... What to look for , with that ? What spot may need to adjust? clean ?

[JUUL]

Your problem may be caused by different issues. I'm not experienced with the 1.0 engine, but I know for a fact that 1.4 and 1.6 engines often have PCV and EGR issues.

EGR & PCV: The valves and lines (to and from the valves) can get clogged which result in poor performance and juddering.
Throttle body: It can get very dirty as well, which can give you fuel/air mixture issues. I would advise to have these all looked at and cleaned, if the problem persists, you can go ahead and dig deeper into the issue.
Ignition & Coil: Check that your sparkplugs and coil leads are working correctly.

[telbert twang]

The throttle body seems OK and clean inside ( treated it with TB cleaner aerosol, though, as i had bought it already anyway).

I discovered that the fwd brakes sometimes lightly jammed after some drive in town - cleaned and lubricated them with brake lube (will get to them more deeply at some point) - perhaps that could have given some performance loss to it´s tiny 37 kW (possibly more like 32 remained real kW or so, by now ) engine.

I also installed new distributor cap , which made some difference towards better ( the old one looks nice clean , but who knows ...) .

New engine oil again.

Will replace the fuel filter soon.

The plugs and wires may get soon changed/swaptested as well (they have been replaced less than 6000 kms ago, look fine, plus I cleaned the wires and treated them also with silicone) . I have a brand new ignition coil waiting to swap / test .

Generally talking - it is a pretty much alive and working car now , with much to improve and refresh step by step.