problems again - help needed!!

[nalobcram]

can anyone advise please???
i had to have a engine rebuild last year because a cylinder went down..
it was repaired ok, but recently it now hesitates(ie it's missing on a cyclinder ) at low revs -when pulling away etc..
its fine when on motorway etc... but also it will flattern out if over-reved..... ( i take it that's the limiter cutting in??)...
the garage that did the engine rebuild have looked and said there's slight oil on one spark plug... but it needs a good run to bed everything in??????

could the mtrec need tuning? is the distrubuter slightly out?? a faulty ecu?? any ideas???

also have a problem with the air con.... it was regassed last year too... but now the compresser isn't cutting in and out... is there a fuse for this??? i've been in the fuse box but everthing is fine... i'm reluctant to spend any more money on this car at the moment
any help thankfully recieved....

[Steve_M]

can anyone advise please???
also have a problem with the air con.... it was regassed last year too... but now the compresser isn't cutting in and out... is there a fuse for this??? i've been in the fuse box but everthing is fine... i'm reluctant to spend any more money on this car at the moment
any help thankfully recieved....

If you bridge the pressure switch that can be found in the pipe at the front of the car near the condensor that should make the compressor run with A/C on, it will then signify if there is any gas in the system.

[nalobcram]

Thanks for the info on the a/c !! i'll go and try to locate the switch...

as for the engine....
i've noticed this morning that it will not rev any higher than 7.5 on the rev counter... ( in neutral)...
would this indicated that a cyclinder is still out??
i thought it rev'd well up to the 9.5 mark.....

[Wh1teLeopard]

Best bet is to do the engine management light check thingy

[nalobcram]

Just been and checked the switch.... i bridged it.... and the compressor clickes in so that means i'm outta gas again????

[nalobcram]

Best bet is to do the engine management light check thingy

ok... whats one of them then??? please???

[old'uns]

http://www.u-ukhbc.co.uk/vbb/showthread.php?t=1448

[Steve_M]

Thanks for the info on the a/c !! i'll go and try to locate the switch...

as for the engine....
i've noticed this morning that it will not rev any higher than 7.5 on the rev counter... ( in neutral)...
would this indicated that a cyclinder is still out??
i thought it rev'd well up to the 9.5 mark.....

Not in neutral.

Check for rev limit on the road, you may have the lesser spotted 7.5k rev problem.

Otherwise do you know th history of your ECU and its capacitors.

[nalobcram]

the engine management light is fine, not indicating anything.... so should i do the diagnostic test on it???



i've had the car for 15 years... the ecu is untouched..... so you think that might be the problem???? it's under the carpet, behind the map box ??? what should i look for???

this is sounding expensive again
many thanks for ALL help!!

[nalobcram]

Not in neutral.

Check for rev limit on the road, you may have the lesser spotted 7.5k rev problem.

Otherwise do you know th history of your ECU and its capacitors.

oh!! the lesser spotted 7.5k rev problem.?????
is it common?? is it expensive to remedy??

[Steve_M]

oh!! the lesser spotted 7.5k rev problem.?????
is it common?? is it expensive to remedy??

Not that common. Unknown cause - as yet no cure found.

[nalobcram]

is it worth getting the ecu out and having it checked and caps replaced??? just on the of chance?? who else has the 7.5 rev problem???

many thanks again...

[professor]

It might be poor conductivity, have your cheaked your king lead and dizzy cap?

[nalobcram]

It might be poor conductivity, have your cheaked your king lead and dizzy cap?

Thanks for the advice.... this weekend i'm going to get the lid off and have a poke around

i've no idea which way to go on this.... it's now not idle'ing smoothly and will fuctulate between
9 and 15 on the revcounter (in neutral , just on tick over).... it will stay steady for five to ten seconds then drop, then rise etc??

i think i'm going to have to start with the basics and go though systimatically... getting more expensive as i go

it could be a number of things....
HT LEADS,(still the originals from new!!)
DISTRIBUTOR CAP,
ROTOR (AND POINTS?? IT DOESN'T HAVE THEM DOES IT?)
DISTRIBUTOR ( replaced a couple of years ago)
ECU ( original-never touched)
FUEL FILTER, ( is there one?)
FUEL PUMP,
PETROL JETS ( original ones)
MTREC (i was wondering if one throttle valve is sticking??)does anyone good on tuning these up or even know what there doing with this system ??

am i missing anything else??

once the car is above 30 mph its fine, apart from bottoming out ....

i really am at my wits end with it at the moment, i can't afford another big bill in effect, i wish i had of scrapped it now, instead of the engine rebuild - sad but true

any thought????
Many thanks for any info !!!

[Steve_M]

You really need to determine if its a running problems e.g fuel and ignition or actually a misfire/mechanical problem.

Could be a valve burnt out and leaking, that will effect idle speed but will be over come when at reves.

Probably best getting a compression test done to see how each of the cylinder compare.


HT LEADS,(still the originals from new!!) Possible would expect it to vary more thou.

DISTRIBUTOR CAP, Centre electrode does burn out and also external cracks

ROTOR (AND POINTS?? IT DOESN'T HAVE THEM DOES IT?) No no points

DISTRIBUTOR ( replaced a couple of years ago) (probably had a new cap and rotor arm then)

ECU ( original-never touched) Capacitors could have gone pop, and in my experiance, chuck it away and get a new one, dont waste your money on repairs.

FUEL FILTER, ( is there one?) Yes, at rear under upper cross member, would not expect to cause poor running like this.

FUEL PUMP, normally give up totally or very noisy

PETROL JETS ( original ones) would not expect problems

MTREC (i was wondering if one throttle valve is sticking??)does anyone good on tuning these up or even know what there doing with this system ?? all valves on the same spindle so wont be just one sticking. no adjustments needed. perhaps clean with carb cleaner, but symptoms not relavant to these.

[nalobcram]

Hi Steve...
thanks for getting back.... i can't see it being a burnt out valve as i've just had the total rebuild...( less than 1500 miles ago)

it seems like timing if anything... is sluggish when starting off then it's like a turbo kicking it and "whoosh!!" its off like a rocket.... not good when your at a busy junction....

i'm i right in thinking that i can slacken the dizzy off, and turn it slightly??? to adjust the timing slightly???

i'm a bit pigged off with the garage that did the re-build... i wanted it done as cheap as possible (didn't work out that way) and in doing so they wouldn't give me an invoice, so i have no come-back on them to repair it

[marcair]

take a look at or short the O2 sensor.

[Steve_M]

i can't see it being a burnt out valve as i've just had the total rebuild...( less than 1500 miles ago)

Why did you have it rebuilt???

What was replaced???

[nalobcram]

Why did you have it rebuilt???

What was replaced???

it blew a cyclinder, there was a pie shaped chuck missing off one of the valves...so...

I had all 12 valves,rings,timing belt etc, and while i was at it, the clutch too...

it was running fine for about 6 weeks ( run-in time!!)... but its progressively getting worse..

i don't fancy getting a new ecu, just priced it up , the dizzy cap and rotor are still available... but new HT leads are NOT!!

[nalobcram]

take a look at or short the O2 sensor.

Thanks for that!.... where abouts is it ?? whats it look like?? by shorting it out, do you mean by a jumper lead? many thanks!!