Dead Spot, Sluggish Performance, Low Torque in Zen LXi

[frankmehta]

Hi guys. My Zen (last model before the God forsaken Estilo) has done just 20000 kms. It has been very very well maintained and riven occasionally.
We get it serviced every 3 months, and in the last 4 services, the throttle body has been cleaned and the injectors have been cleaned twice due to the following reasons.
The car drives OK with the a/c off, but switching on the A/C absolutely KILLS it. There is no pickup, no semblance of torque, and a very very pronounced dead spot in all gears after 1st. The car needs to be revved to somewhere around 5000 rpm to get some amount of respectable performance with the A/C on. Now I really don't know what has happened, but this is really drastic and really amazes me how badly the car can drive. The clutch is in super condition, the brakes have been serviced (so no jammed canister etc.) and no other changes have been made to the car.
20k is not a large amount and the car should be coming into its own now, since the engine would have opened up totally now. I am confused.
All checkups and services have been done at Vitesse, and the car has also been checked at 2-3 different workshops since Vitesse might have got something wrong. No One understands the problem and I am really concerned. It has made me hate the car now, and I refuse to take the wheel, because my Esteem (double the age, double the mileage done) drives WAY better and the 300 cc and 25 bhp difference never felt so large.

The car refuses to climb slopes without reasonable amount of clutch and insane revs have to dialled in. The dead spot was very pronounced when my parents and sister went with the car to Mahabaleshwar and the car Huffed and Puffed its way up the ghats!!
What is wrong with my baby?
The average returned is erratic and sometimes it gives 9-10 kmpl and also comes down to 7 when I drive it (since I rev it quite a lot).
No one particularly understands this problem but I need some suggestions soon..

[Hashim]

There can be few reasons:
- AC system overfilled with gas causing too much load on engine to run compressor.
- Something wrong with compressor itself?? Does it cool well like before?

BTW, Did you try ECU reset? remove the battery cable for sometime and then attach it.

[frankmehta]

a/c has been regularly serviced too, and the last time it was checked, gas levels were normal and didn't require any topping up. the a/c cools reasonably well, and there is no perceptible difference in cooling since quite a long time. It has improved slightly, but that is due to the windscreen film I got applied last month.
as for the ECU reset, it was done in the MA.S.S and there was nothing wrong found even in the Diagnostic Device when connected to the ECU.
I am perplexed!!!!!

[mobike008]

OT : I had an almost similar problem with my Viva CRDi. Once a year it suddenly develops a different demeanour. After shifting to second gear, when i press the accelaration, it should normally shoot ahead. Instead it just stops ( as a computer hangs) and when i shift quickly to higher gear it moves ahead. This happens for first few kilometers and suddenly disappears. It is a major cause of embarassment while driving in thick traffic when your unable to move ahead due to engine not responding to your frantic accelaration thrusts

Previously had got it checked with A.S.S who were scratching their heads unable to identify the cause. And, as suddenly it appears, it vanishes for good to re-visit after a year or so.

The above problem struck me this morning after a long gap. Let's see what happens tomorrow.

[breezydrive]

Oh! That bug just hits once in a while to this otherwise perfectly running engine. And this disappear on its own surprisingly. Sometimes, I wonder when the same engine climbs effortlessly over the flyovers in the 5th gear at 50-60kmph with AC on & still ready to take on further press of pedal without downshifts.

No point in scratching your head to find the solution to the problem. In fact, the more you get angry (revv to 5K) with her, the more stubborn she turns. Zen has a peculiar ECU settings. My daily drive to office involves aggressive/ spirited driving for first 30 kms on almost empty roads followed by 10km crawl for good 35 mins. The same car becomes a bullock cart after 10mins.of crawling, AC on 100%. BTW, mine is with a mpfi BS-II engine & y'day, she completed 1.15 k on the odo. And never she has complained on the highways, I have taken her to almost every nook & corner of Noth India. But, this special feature arises only in crawling city traffic!

Just check that the coolant ratio is OK & the coolant is actually there. I've seen reputed MASS centres topping up the tank with distilled water ( & charging for full qty. of coolant). Inspect running of fan & also get the AC serviced.

[ghpk]

Frank ji, give me a day, i'll check with someone who had similar issue, will have to visit him to ask as i don't have the number, but i'll check it by tomorrow for you.

[frankmehta]

ok cheers guys!! i definitely DONT wanna live with it. if it involves an ECU remap, so be it.

[desideep]

Originally Posted by frankmehta

ok cheers guys!! i definitely DONT wanna live with it. if it involves an ECU remap, so be it.

Hey Frank i am having a simmilar problem
even my 2002 Zen would give simmilar problems. but it seems that my cars clutch presure plates may be problematic.

[amit_mechengg]

is the exhaust clean? my car had lost on top speed and pickup. the canister and the exhaust was cleaned. also engine flushed. it returned back to 100%.

also check all the belts if overtight. check the engine timing with AC on. also hook in the tech2 and read tps, iat and other readings.

[prince_pervez]

I have been experiencing the same lately. Sluggish engine in 2nd gear. Will an engine overhaul help here ?

[Jaggu]

Start with the basics and try to isolate each suspect in a step by step approach. Do a check on cylinder compression to know the overall health of engine mechanicals. Then proceed to do a valve clearance adjustment and take a compression reading. See if there is an improvement in reading.

Move on to the ignition system, including plugs, coils and wires/leads. Replace the plugs to good ones like normal NGK, if worn out or not replaced for 10k kms. Do a clean up/replacement of air and fuel filter.

While doing throttle body clean up, ensure its done manually by disassemble and not using those spray can thingies.

Once all these are done drive around and see how the car performs without AC, power, mileage and engine temp. If all is fine, start with AC drives and see if there is a huge drop (minor drop will happen since its a small engine unlike esteem which has good surplus power).

If the drop is huge, then start checking the ac system like compressor (compressor clutch failure can be a suspect), gas charge (too high will put higher load on engine) etc.

Most important ensure fuel if of right quality and spec, normal unleaded gas will be the best for a zen engine.

[simply_sunny001]

Frank

try resetting the ECU and lets see if your baby recovers her memory of old days. and after that if i were you, i would have the clutch checked by an expert or maybe two.

cheers

[desideep]

what is the best place to get the ECU checked and all that stuff in delhi and i would also like to know how much should it cost in NCR.

[gpa]

Originally Posted by Jaggu

While doing throttle body clean up, ensure its done manually by disassemble and not using those spray can thingies.

Jaggu,

Most M.A.S.S outlets use a 3M throttle body cleaner in a can. How would a disassembling of the part help in better cleaning and also, will a M.A.S.S do it?

Thanks,
gpa

[scorpian]

well the throttle body is best cleaned when its disassembled,just spraying the cleaner on the throttle plate dosent help,i learnt it the tough way,the cleaner was sprayed in to my throttle body and my car started to go off,kinda jerky idle the M.A.S.S technician said this is normal,and went on doing the same,after some time i could see smoke come out of my exhaust,next day in the morning in the cold start i could hear clearly valve clatter...

In my next service i spoke to the mech and asked him to disassemble as i wasnt satisfied the last time and my idle would remian at 1k,he disassembled the whole thing,cleaned the IAC valve at the bottom,changed the two gaskets and guys you must see it to beleive the amont of carbon that comes out from the throttle body,i watched the mech very carefeully and now i buy 3m throttle body cleaner and do it myseld at home,its not that difiicult...

If you insist they surely will disassemble and clean it..