Tuning advice

[matt-man]

Hi All,

Pleased to say that the car is running and seems to be going well! (fingers crossed!)

Only thing is that it isnt running 'perfectly'. I believe this is down to fuel pressure as Ed and I lowered this when going through the fixing process.

The car has what i can only describe as a flat spot and hesitates a bit a certain RPM. The flat spot is as it comes onto cam...

Anyhow, we set it to 29PSI (it was running 46!) but dont have a gauge myself so tried just turning it up a bit (bad mistake) and now cant get it to go as well as before!

So question is, anyone know of somewhere where i can get it set up right? Dont want a full tuning just want it to run correctly...

Cheers guys,

[Wedg1e]

Find a pressure guage, replace the cold start injector with it and adjust till you're happy.

Lookee here:

http://www.pressuregauge.co.uk/01_general_purpose_...

Something with the inlet at the 6 o'clock position rather than rear-entry, probably a 1/8" BSP fitting. Add a brass hose tail (Machine Mart as a last resort) and a couple of Jubilee clips and away you go.

Edited by Wedg1e on Friday 15th October 18:59

[B-Reight]

Matt, iirc your car is a 4ltr flapper, the correct fuel pressure is around 46 psi.

The 36psi figure bandied about is for stock landrovers with ~160hp, TVR did modify the fuelling of the ecu but not enough (probably limited by the ecu itself as it's not microproccesor controlled like the later hotwire ecu)

Get yourself a fuel pressure gauge and put it back to where it was, these engines still run suprisingly well when running dangerously lean mixtures.

Even better buy/beg/borrow a AFR/lambda setup or get on the dyno to get it set up properly (but be aware that most RR operators won't have the foggiest about how the L-jet system works)

[HOTTY]

B-Reight said:

Matt, iirc your car is a 4ltr flapper, the correct fuel pressure is around 46 psi.

The 36psi figure bandied about is for stock landrovers with ~160hp, TVR did modify the fuelling of the ecu but not enough (probably limited by the ecu itself as it's not microproccesor controlled like the later hotwire ecu)

Get yourself a fuel pressure gauge and put it back to where it was, these engines still run suprisingly well when running dangerously lean mixtures.

Even better buy/beg/borrow a AFR/lambda setup or get on the dyno to get it set up properly (but be aware that most RR operators won't have the foggiest about how the L-jet system works)

daft question but you do mean 4.6 bar ?

as i have a pressure gauage in line, it ws only running at 2 bar at the BBWF, so on the rolling road NTR turned it up to 3 bar .
The 400SE was still way down on performance so we swopped the air flow meter (kindly given for the day by "one finger bandit") things got better, just.
Been out and purchased a re con airflow meter but i feel the car could do with setting up.
It now struggles at about 3000RPM (ok at 3500RPM) and did so on all of the rusty nail run ..... Honest Hamish......

I have turned it down again to 2.5 bar to see if the problem went away (trial and error thing)

i will now turn it up to 4.6 if thats were it should be.

is there anything else i can muck up to ?(allen key on the airflow and screw on the plenum , should i give these a go)

hotty

[HOTTY]

matt-man said:

Hi All,

So question is, anyone know of somewhere where i can get it set up right? Dont want a full tuning just want it to run correctly...

Cheers guys,

if you get a answer Matt i would be happy to know too, as the more i change the worse i am sure it will be.

only want the car running right too

[B-Reight]

Hotty, no definitely not 4.6bar!, 3.5bar/50psi is about the maximum that should be run with this system, at 4.6 bar the injectors won't operate properly and may leak (not to mention worn fuel hoses may turn into petrol sprinklers.

When you had it on the rolling road did you get a print out of the fuelling along with the power output? I presume if NTR were monitoring fuel during the run they would have set it correctly.

Fuelling really needs to be measured properly on the dyno, turning pressure up and down by ear ain't recommended and what works for one car may not be suitable for another as there may be different injectors and different ECUs.

At 2.5bar/36psi my cars afr was 16:1 under WOT which isn't going to do the engine any good, likewise too rich and you'll end up with fuel in your oil and accelerated wear hence it needs to be done properly.

Another thing to look at is your ignition system, almost every landy tech i've chatted with has said 9 time out of ten it was the ignition causing running problems and the fuelling system is pretty robust. Checking ignition timing through the rev range may be worthwhile, along with physically checking the dizzy out for mechanical wear (advance springs can stretch, the shaft can wear out and give play/slop in the mechanism). Ignition modules also seem to fail progressively with the high temps under the insulated wedge bonnet.

[B-Reight]

Why did you replace the airflow meter, they are quite robust units and there isn't a great deal to go wrong with them bar occasionally sticky spindle bearings, or the resistor track wearing through after prolonged service, the only one i have seen that had failed due to this had come from a 160k mile range rover.

The allen key on the air flow meter is an air bypass and is used for adjusting the idle mixture, it bleeds air past the air flap and thus leans the idle the further you screw it out, it does have a small effect above idle but not much, don't worry about adjusting it at the moment, you might need to use it come MOT time.

The plenum screw is idle speed (which isn't ecu cotrolled at all on the flapper system).

Edited by B-Reight on Saturday 16th October 13:23

[HOTTY]

B-Reight said:

Why did you replace the airflow meter, they are quite robust units and there isn't a great deal to go wrong with them bar occasionally sticky spindle bearings, or the resistor track wearing through after prolonged service, the only one i have seen that had failed due to this had come from a 160k mile range rover.

Edited by B-Reight on Saturday 16th October 13:23

Before i had the car
The car had been not used really for 9 years (couple of thousand miles only as recorded on the mot's)
The car had been tuned in chesterfield by the previous owner but strangely had the same details/print outs but with a years difference, so i called in to find out why ! He remembered the car as it had sat in his garage for a 11 months !
In tuning it he said that he had to alter the airflow meter, he thought and advised to get the airflow meter changed.
The car had a full mot when i took it home.

I thought i had found the problem as the performance increased after i replacement coil orignal was a duffer, replaced with a lucas part and increased the earth cable to the alternator.

Went to the BBWF and on the rolling road they confirmed/advised that the airflow meter was not working correctly (i will get the print outs posted) swopped it, altered the bar pressure....improvement.
But it was not my airflow meter, so i found one on ebay recondition.

Currently i need to buy a rotor arm and a dissy cap (lucas hopefully) did fit new before the rusty nail but was intermotor ? but they made the car run like crap, so quickly changed them back to the old.

never had a problem with tick over and today there seem to be a improvement with the increase back to 46psi (one question is with that with the vacum pipe fitted ?)

cheers
hotty

[Tasmindevil]

36 psi is about the norm, as noted upto 50 psi on flapper systems, if the car hestitates at certain revs then possibly fuelling may not be an issue. Prior to touching the fuelling I would check the timing and the general condition of the ignition system, vacum pipes etc, I recently checked mine using a DTI down No1 cylinder and found TDC a good few degrees out. I had a similar hesitation problem with HOB, the One Finger Bandits car, certain revs it just stuttered, did the rounds and found a combo of worn dizzy and knackered weights along with a vacum leak through the servo.
Good luck
Hamish

[honestjohntoo]

HOTTY said:

In tuning it he said that he had to alter the airflow meter, he thought and advised to get the airflow meter changed.

advised that the airflow meter was not working correctly

so i found one on ebay recondition.

Oh Dear! The chances of getting your AFM set up to suit your engine is now seemingly down to chance unless you have some reasonable idea how the unit works and how to make changes to the mixture over the whole range, either empirically, or with some measurement of CO.



Fear not, help is at hand.

Everything you might possibly want to know about your AFM and how it might be adjusted to suit your needs can be found in downloadable PDF format from here

On the same link you will also find a technical guide to Carbon Monoxide (CO) content, detection and analysis, for further reading and research.

Good Luck!

[matt-man]

Hi Guys,

That all sounds very interesting! Looks like a Rolling Road is a good idea...

I have been in touch with Paramount performance (you might know them as Jag and Aston tuners) as they are local and they would be happy to set it up for me (really nice guys on the phone) for £300.

Does anyone reccomend someone else in the south east who are maybe v8 specialists??

Cheers, Matt

[B-Reight]

Sounds expensive, do you know what you'd be getting for your £300? I'd expect to pay that for a mapping session, but since this system can't be mapped they'd likely be advancing the timing a bit and twidling the fuel around a few psi.

When i first got my car, and before i got to grips with the FI system, i paid £120 for 2 hours on the dyno for a 'setup' which they (not paramount performance btw) made a pigs ear of.

Edited by B-Reight on Monday 18th October 13:44

[TVRleigh_BBWR]

Does seem a bit expensive,
Most Rolling roads are about £80 per hour for mapping, or less for just a power run,

I can't see it taking more than an our to set the fuelling and timing, seeing as there is only one adjustment of each.

[Campbell]

Its about 55 quid for an hour up my area, you may need to ajust the air flow meter to soot the timming and fuel pressure through the revs, its would be a good idea to find out if the garrage has a crypton tunner to monitor the ignition timming and dwell angle as this can tell if your dizy it on its way out like mine was twice....grrrrr....
Take a spare ignition modual, dizy car and rotor if you have them plus a print out the the notes from the vitesse pages on the flapper for voltages and setup.
Good luck with getting setup proper, makes so much of a difference.
Need to mine again...

Cambelt

[ed_crouch]

Hey Matt. I can drop by with my pressure gauge if you want?

Otherwise get Charlie at Surrey Rolling Road, vixpy on here, to have a look.

[matt-man]

Thanks all for yor advice, i thought it seemed a bit expensive too...

I have just emailed vixpy to see if he would like to do it, that way i know what she is doing at any time...

Ed - If i can get vixpy to set it up i shouldnt need to bother you, but i could let you know when (and if) i am going if you fancied watching?

[HOTTY]

matt-man said:

Thanks all for yor advice, i thought it seemed a bit expensive too...

I have just emailed vixpy to see if he would like to do it, that way i know what she is doing at any time...

Ed - If i can get vixpy to set it up i shouldnt need to bother you, but i could let you know when (and if) i am going if you fancied watching?

have you been matt ?

as i have to book up next week, found somebody very local,£60 for 1 hour (wish i got 60 per hour)

but currently dont know what to print off so he is not wasting his or mine time.

hotty

[matt-man]

No I haven't heard back from him, need to call and chase. Ed is going to come over and set it up with a gauge and hope to finish it off on the rollers.

Good luck!!