1.8 16v bad fuel economy.

[Langsam 10]

Hiya, I've been searching around a few forums but with no joy on getting a answer. Over the past few weeks the fuel economy on my 1.8 16v has been getting worse, I average over 100miles per day in my corrado mostly motorway mileage at 60mph. But quite recently it has started to run rich, to the point where nearly everybody says something. Even when fully upto temp it stills smells rich.

 

I run the car on either v-power or tesco 99 and it always has regular oil changes.

 

Ive cleaned the ISV and its made no difference. I even tried to adjust CO by using a guide on clubgti, but my corrado didnt even want to fire when trying to do this.

 

What could you recommend?

 

Thanks

[Human Joist 10]

I used to have a mk2 golf 16v Gti. I got hold of a complete set up guide in an old Golf+, it detailed everything from where the connectors should all be to co2 set up and timing. It was published years ago and used as a point of reference for bad running valvers. I presume that it will all be the same layout on a corrado. I will have a look over the next few days and see if I can dig it out. Then either scan or photo it and post it on here if that's any use mate. I got a couple of cars back to perfect running order from this. Unless you are 100% it's all set up right it might be worth doing this as a starting point and if it does not cure all it will at least have the rest of the car as it should be which may eliminate some possible faults. Let me know if you want this

[Langsam 10]

That would be ideal, cheers mate.

 

Then at least a mod could sticky it.

[Wild-Animal 0]

It could be your warm up regulator, WUR if its broken then the engine could be trying to stay in warm up mode which would mean richer fuel. Its just an idea, other than that if the cold start injector is staying open.

[Langsam 10]

How can I check to see if the WUR is broken? And where is it located?

 

Thanks

[Human Joist 10]

Someone else might correct me. But from memory the warm up regulator controls what is know as the 5th injector. Looking at the engine from the front there should be a fuel pipe that runs along the top front of the engine. On the right hand side of this pipe when looking at the car is the 5th injector. This is controlled by the warm up regulator which sits just under it and is connected by a wire from memory, it fires extra fuel in to the engine when it detects its under a certain temperature. The easiest way would be to remove this injector and get a friend to start your car with it in a jar so you can see if it fires. You can do it with engine cold and then with engine warm. It should fire in a fine spray and not drip out.

 

Other things to check are the seals around the injectors and the injectors themselves as they should all work with a fine spray. There is a lot to consider. Especially when removing the injectors as the seals will most likely be hard and may break. Also the plastic housing the injector pushes in to are renown for getting brittle as they age. If they break and you replace them be prepared to take of the intake as you don't want bits to drop in to the block.

 

Prior to removing injectors you can spray them with wd40 they should bubble and the engine may struggle if they are leaking outwards. The injectors are about £125 ish for the four and that comes with seals and the plastic guides are not much. They should last for about 100,000 miles and then be replaced or refurbished. I bought mine new from VW.

 

Also not knowing how mechanically minded you are when you adjusted the co2 screw you need to be very careful you don't go too far as it will drop out in to the box and its very fiddely to get it back in again.

 

I had no end of problems with my last one. Hence me using the guide first. It covers lost of points. I hope to collect the mag from a friend tonight and I will get it on later. These will keep you busy for now checking

Edited September 24, 2012 by Human Joist

[Langsam 10]

I thought thats what it was but wanted confirmation, just incase. That sounds very easy to do.

 

Ive not adjusted the co2 screw, because it didnt even try to run when just unplugging the red and black wire at the coil and blocking inlet. I did make sure however that the engine was upto its normal working temp aswell.

 

I'll try the injectors and the WUR and get back to you.

 

Thanks for all the info, its much appreciated!

[Human Joist 10]

Not sure what you were tying to do with the red black wire and blocking inlet. But be mindful with the red black wire at coil as they can create a shock that kills if the earth is naff.

[davidwort 0]

Hi chaps, WUR does not control the cold start valve, the thermo-timeswitch bolted to the head does that (the larger of the senders on the end of the head) the varying resistance of this can be checked off the car with a multimeter and some warm water, I have the temp/resistance graph somewhere.

WUR alters control pressure at the metering head, which does affect fuel delivery but mainly at the mid range and top end.

It would be a good idea to get the injectors checked, easy enough to do by jumping the fuel pump relay contacts, lifting the air flow plate in the metering head and pulling the injectors and spraying into bottles.

Are all your plugs the same colour? fuel issues will generally show up as all of them the same (sooty if rich)

 

[ATTACH=CONFIG]69518[/ATTACH]

 

my old injector test thread: http://the-corrado.net/showthread.php?43319-my-testing-the-injectors-on-a-KR-(K-jet)-16v&highlight=injector

Edited September 24, 2012 by davidwort

[Langsam 10]

Jim Southan this is what I was trying to do, although I have most probably miss-interrupted it haha.

http://www.clubgti.com/showthread.php?195423-HOW-TO-Correctly-set-up-a-16v-(prevents-stalling-when-cold!!)

 

David wort- The thermo-time switch is that one of the sensors underneath the dizzy?

The spark plugs are the first thing I was gonna check once it stops raining. Cheers for the info and graph.

Edited September 24, 2012 by Langsam

[Human Joist 10]

Should be able to get the mag and set up guide on in next few days. If it would no start once you unplugged the wires it could lead to your timing being way off.

[davidwort 0]

David wort- The thermo-time switch is that one of the sensors underneath the dizzy?

 

yep, there's 3 small sensors(black tops, all the same part) and one larger one, the three small are dash water temp gauge, idle control and ecu I think, the third larger switch that has two connections is the thermotimeswitch.

[tentonhammer 10]

Mine's running a little too lean for my liking these days and the bay stinks of fuel after a long drive. Will def need to look at injectors / fueling etc over the next few weeks.

 

So far: New ISV fitted. New plugs and leads fitted. New coil fitted. New distributor fitted. New metering head fitted a year or so ago - Still hasn't sorted it.

 

Other things to check are the seals around the injectors and the injectors themselves as they should all work with a fine spray. There is a lot to consider. Especially when removing the injectors as the seals will most likely be hard and may break. Also the plastic housing the injector pushes in to are renown for getting brittle as they age. If they break and you replace them be prepared to take of the intake as you don't want bits to drop in to the block.

 

Jim - I'm hoping to replace my injectors soon as I'm up to 96,000 Miles. So basically, if you check the injectors be prepared to have a replacement set on stand by, new seals the lot?

 

Diagrams also go a loooong way guys ;)

[Langsam 10]

I suppose it doesnt help them being covered in oil from my dizzy aswell another thing on my to do list aswell.

 

Mine has just creeped over the 168,000 mark, so it may well be overdue some new injectors? Although I did put some injector cleaner additive when I first pulled the car out of hiding and it ran alot better afterwards.

[tentonhammer 10]

I suppose it doesnt help them being covered in oil from my dizzy aswell another thing on my to do list aswell.

 

Mine has just creeped over the 168,000 mark, so it may well be overdue some new injectors? Although I did put some injector cleaner additive when I first pulled the car out of hiding and it ran alot better afterwards.

 

I use brake cleaner or Isopropyl alcohol (spray type) on all my connectors - Great for removing oil and all kinds of cr*p and because it's virtually pure alcohol it evaporates in a few seconds.

 

Sounds like you should def give your injectors some attention after 168,000 miles!

 

Jim - out of interest how long does it take to replace all injectors etc, whilst taking the correct precautions of course?

[Langsam 10]

Does anyone have the part numbers for a 1.8 16v injectors? And is it also a easy fix to renew the seals in the dizzy aswell?

 

Thanks

[tentonhammer 10]

What year?

[davidwort 0]

seals are easy to push on, removing old seals from old injectors is the usual problem, or removing said injectors from head, best to warm and soak with WD40 before attempting to remove as old hard seals make it difficult to pull the old injectors out.

 

Oh, and cleaning K-jet injectors is not very successful, the injectors actually wear and no amount of cleaning will fix them, after 100k or so they are really past their best for efficiency and idle/low throttle running.

 

1.8 injectors are the same as mk2 golf 16v ones, 2.0 16v corrado ones are different and operate under different pressure, but the fitting is a different thread so you can't fit them to the 1.8 fuel lines/pipes.

[Langsam 10]

its a 1990.

 

Ive just been quoted £499.87 for 5 injectors from TPS near me.

[davidwort 0]

no, no, no, no, no, :) just get 4 of the main injectors and from GSF or similar, GSF have them for about 46 quid each incl vat, but you may be able to haggle a trade discount (10% or so) from them

[Langsam 10]

Hahahaha ahright, I nearly swallowed my mobile when he quoted me that price!

 

Ok I'll give them a shout thanks.

[Human Joist 10]

When it comes to replacing the injectors I can help with the advice as I did mine on a 1.8 16v KR which is the same as the 1.8 radio discussed in this thread.

 

When removing the old ones, yes as mentioned earlier spray them with wd and let them soak first. They should just pull out. It does not feel natural when you do this. You just grab hold of the top of the injector where the braded pipe joins and then give it a sharp pull to come free. Sometimes if they have not been moved before or for a long time they are in there tight. Once out you can test them but the factory advice was always 100,000 so it's worth replacing them anyway. I looked round to see about refurb but it was not that much cheaper and you still had to send yours away etc etc so I went for new.

 

I would suggest main dealer as its an important and accurate part of the car. But cost is always an issue. Mine came with the little rubber seals to go on the new injector as you would expect from main dealer. You then simply fit them to the braided hose. The plastic guides are fitted in to the intake manifold and from memory take a socket or extension to them to twist them out but you can guarantee they will be original and brittle as anything. So from personal experience I would get a set of those two. The best way to do this is to remove the entire manifold to guarantee bits don't end up where you don't want them. But that's easy to do. (You could also use it as a opportunity to have it powder coated at the same time for a nice touch) replace the plastic guides then replace the inlet manifold then push fit the injectors with a tiny but of copper grease just to make sure they go home correctly.

 

I have a good friend who works at VW on parts. So when I did mine I got them from him and they were not that much more than a GSF job. I will pop and see him tomorrow to see what sort of price he can get the lot for, injectors, seals and guides. Then put that on here after in case anyone wants me to get them a set. I like places like GSF and euro car parts but would stick to VW if funds allow, the originals lasted for so long so the next lot should outlast the car.

Edited September 24, 2012 by Human Joist

[Langsam 10]

Cheers Jim mucho appreciated for the info and price quote aswell.

 

I have now just found out that I've got a new job so no more 100mile round trip to work and home, everyday of the week for the Corrado!

[Human Joist 10]

If you want 4 genuine injectors its £253.66 and the guides should be £21.20 for the 4. Saying that it would be more if you walked in and asked without discount.

 

The price has gone up quite a bit since I bought them.

 

Euro Car Parts have just quoted me Bosch injectors for about £60 + VAT each. I have a friend with a trade account at one of their stores locally to me and could get them for about £40 each plus delivery if that helps. Let me know if you can't get them cheaper and I can sort it for you. Let me know bud.

[Langsam 10]

My mate also has a trade account at eurocarparts so thats not too bad. Whats the part number for the bosch items from euro?

 

Thanks again for all the help Jim your a star!

 

Its also always done this when idling cold it will stay around 1000rpm and generally hunt between 800 and 1500, then when fully upto temp it will idle around 1500 to 2000. Normally when it idles around 1500 to 2000 I have been driving for sometime and then stopped at some lights and noticed this but even when just tickling the throttle pedal it will still sit at around 1500 2000 depending what mood its in haha.

Edited September 26, 2012 by Langsam