hey this site and the information is great. have been worried about the electrical side of motors for a while and stumbled onto this site in a search session. awesomely informative with good examples of application. Thanks again-Brilliant!
Hi there from the UK! I love your site and I agree with your review on the Fiesta Zetec, its a great handling car and was well reviewed here as well. I only drove one for a few days but it was great, I went berserk on a favourite back road and it held its composure much better than my old Fiesta, and even a Peugeot 306 I remember driving. As you said the problem is they should have given it more power, but the higher insurance rating wouldn't be friendly for young drivers here (we get a slightly bodykitted 'warm hatch' version of the 1.6 Zetec as a Zetec S) and also the gearbox can't take the torque. Really Ford should have designed a new gearbox for the Ford Puma 1.7, as the torque was restricted in 1st gear to prevent damage to the box. That's also why they had to put a completely different gearbox/engine series in the 2.0 ST they market over here, with 150bhp it would have been playing Russian Roulette with the old IB5 box. Sorry for such a geeky response, keep up the good work.
Airflow Meter Change
The time has come to seek your expert advice. I am about to replace the MAF sensor on my car with a MAP sensor. I read your article on teh subject, and I know you do not recommend it, but this is last resort. I have a 1991 Mercedes w124, 2,3L petrol engine with KE-Jetronic continuous injection. It measures arflow with a vane type MAF. Problem is after 200 000 miles on it, the tracks on the little pot are gone, Bosch does not offer the little pot as a separate part,and the whole MAF unit costs about half the car - almost 1000 Eur. Buying a second hand replacemnet does not guarantee trouble free installation. I have to adjust fuel mixtrue every day - after a while the ECU enters into trouble mode, and I have to delete the 4 flashes trouble code, and readjust mixture after that. I am planning to leave the vane intact, as it is also mechanically coupled to the KE-Jetronic fuel distributor, and use a MAP to measure air volume instead of the potentiometer. I measured 0.5 bar of vacuum at idle, will a 1 bar MAP work? Originally, at idle the pot should give betweem 0,5-0,7, and about 5V at WOT
We've said it all at Why to Not Swap Airflow Meters
Referring to an article of Real World Air/Fuel Ratio Tuning by Julian Edgar. The scope meter readings look as if they could have been subjected to impulse or alternator noise, resulting in incorrect values. Was the scope meter used as a scope or a meter (if that is possible?), I am thinking here that the volt meter mode may sample at a lower samples per sec? Was any averaging used?
The Scopemeter trace looks fine to us – in the pic it is showing closed loop cycling.
I have been a keen reader of Autospeed for
quite a few years now. It's the only site I can think of where the "technical
info" presented isn't subtly linked to selling something. Reading your articles
on parts, books, new cars etc., makes much other motoring journalism seem overly
enthusiastic and conspicuously non-critical. I guess that's why you have a
longish lists of car manufactures that won't loan you cars! So long as your
opinions are based on your observations and facts, good on you. There is so
little non-commercially motivated information around as it is.
We expect to DIY cover bio-fuels in 2008.
Julian Edgar worked as a secondary school humanities teacher for 8
Re throttle body story, "AUD$" is like "PIN number".
Hmm, AC current anyone?
Prius HV Batteries
Does Julian still have any NiMH bats left from his attempt to charge his battery externally?
Some, but he is keeping them.
I was looking into the audi boost mod> The Audi's DIY Boost Control - Part 2 now
in article one, you say that you un-plumb the solenoid (n75 valve) but leave the
loom fitted, i take it that you then do not use the solenoids fittings at all
and dimply use it to say its still plugged in? but with air not going through
it, would the ecu not realise this? or do you put your regulators inline
with the solenoid. im getting kinda confused as you can tell
The ECU doesn’t know that no air is passing through the solenoid.
I read your articles about ignition timing,
ram-air and closed-loop monitor with great interest! This is very good
Perhaps some early cars using oxy sensors for closed loop did not have any self-learning (ie they just used a fast feedback) but certainly most have long and short-term fuel trims (ie self-learning).
Human Powered Vehicles
I have been reading your "Building a Human
Powered Vehicle" series with great relish. Julian Edgar has done a marvelous job
of communicating the ups and downs of creating what at first appears to be a
child’s toy but instead turns into an unexpected drama of applying
exuberant creativity and exhaustive energy to higher engineering. The highly
sought-after technical information for this class of vehicle is presented is
such a practical and matter-of fact manner that I sometimes forget that much of
it is over my head.
To the matter at hand, I can not find the
conclusion (i.e., part 8) of the first HPV series, No matter how hard I look! I
wish to finish the series before I go to the next one, "Another HPV". My son and
I are designing and building an HPV (maybe with electric assist). We want to
design it as "high-tech" as possible, yet still keep the project within reach of
an average DIY guy without a welder (I.e. me). Your HPV series has become
invaluable for us on many design challenges, especially suspension and
We suggest you go onto the next series, which is a much better design.
I read with interest the article on MODIFYING
THE COMMODORE'S LS1 5.7-LITRE V8 & am now wondering if I am wasting my time
with Over the radiator air induction,extractors,2 1/2 system etc ?? Every
article I read on otrai claims better performance etc !! Are they kidding
themselves? I don't want to waste money if it's a 3 day wonder ??
We’ve never seen an engine that doesn’t improve in some way – be it fuel economy, power or throttle response – with better breathing.