Running Rich and idle problems

[Chilli Girl]

This is her,

Not sure if the previous owner was a member, think he sort advice from here on the rebuild.

Do I detect an early VW Camper in the background?
Nice.

[jonbill]

an air leak after the throttle is still unmetered air, so would make it lean. (and idle would be high)
would be good to see pic of those spark plugs.
is it using much oil?

[M.Dub]

Yea

This is her,

Not sure if the previous owner was a member, think he sort advice from here on the rebuild.

Do I detect an early VW Camper in the background?
Nice.
[/quote

This is her,

Not sure if the previous owner was a member, think he sort advice from here on the rebuild.

Do I detect an early VW Camper in the background?
Nice.

Yea my dads project, it's years in the making lol.

[M.Dub]

an air leak after the throttle is still unmetered air, so would make it lean. (and idle would be high)
would be good to see pic of those spark plugs.
is it using much oil?

Iv binned the old plugs but they was pretty heavy in carbon, I had misfire codes on all 4 that cleared when I changed the plugs. Iv had many issues to resolve with this car already!

My favourite was when it blew its fuel hose off behind the drivers seat and filled the car with fuel. The clip that holds the hose to the pump hadn't been put back on. Had to strip the whole interior. Good job I don't smoke.

[M.Dub]

No it doesn't use any oil that Iv noticed.

[jonbill]

I wonder why the fuel pump hose had been taken off in the first place. If the pump has been replaced with an aftermarket one with too high volume or pressure might overpower the regulator 🤔

[M.Dub]

Iv thought the same, Iv got a second hand replacement pump etc on order so I was going to swap that out to see if it made a difference. Think the hose has been off because the car has previously been stripped and re built.

The car never fails to start first time, if I had leaking injectors would it flood and struggle to start?

Also if the injectors are too big cc
Would that cause a over fuel? 

[shnazzle]

Definitely.
Argh why won't people just leave these cars alone eh @Carolyn 

[jonbill]

Both larger than standard injector (cc) size and higher than standard fuel pressure will make it run rich.
The ECU only controls the amount of time the injectors are 'on', and that amount of time is only valid if everything is as it was when the map was developed.

[M.Dub]

Both larger than standard injector (cc) size and higher than standard fuel pressure will make it run rich.
The ECU only controls the amount of time the injectors are 'on', and that amount of time is only valid if everything is as it was when the map was developed.

Perfect thank you all for your help I really appreciate it.

Looks like iv got a busy weekend ahead.

I'm going to replace the fuel pump etc and if that doesn't fix anything check a injector to see the cc, I'm assuming it's stamped on the side?

I'll change them if they are too big. Was the OEM 250cc?

Iv also got a OEM MAF from when I salvaged a standard air box so might give that a clean and see how it behaves.

Even tho everting Iv bought claims to be OEM / Denso I just don't trust them 100% so many fakes out there.

[Carolyn]

Both larger than standard injector (cc) size and higher than standard fuel pressure will make it run rich.
The ECU only controls the amount of time the injectors are 'on', and that amount of time is only valid if everything is as it was when the map was developed.

Perfect thank you all for your help I really appreciate it.

Looks like iv got a busy weekend ahead.

I'm going to replace the fuel pump etc and if that doesn't fix anything check a injector to see the cc, I'm assuming it's stamped on the side?

I'll change them if they are too big. Was the OEM 250cc?

Iv also got a OEM MAF from when I salvaged a standard air box so might give that a clean and see how it behaves.

Even tho everting Iv bought claims to be OEM / Denso I just don't trust them 100% so many fakes out there.

The injectors tend to be colour coded.  Standard are green, the next up (2ZZ) are yellow.

[M.Dub]

Hi everyone,

Just thought I'd update you all and hopefully this will help others having the same issues.

It was the injectors!

They looked decent enough and all the seals etc were in good shape but soon at I swapped them out for some new ones the rich running stopped and so did all the idle issues. Don't think they were leaking just over sized.

I have developed a misfire on cylinder 1 but I can't notice it when driving the car. Think it's flagging it up on idle. Could this just be the injector not seated properly and getting a small vacuum leak?

Cheers 🍻

[jonbill]

Thats good news.
I'd think your misfire might be a fouled plug.
maybe take them out and clean them and try again?

[jonbill]

what markings did the duff injectors have? same as the good ones?

[Ardent]

Good news.

The collective strikes again.

[M.Dub]

The injectors had the same part number but different numbers stamped on the opposite side.

Not sure on the misfire as Iv not touched the plugs for weeks and I have only got the misfire code after changing the injectors.



 

[shnazzle]

The injectors had the same part number but different numbers stamped on the opposite side.

Not sure on the misfire as Iv not touched the plugs for weeks and I have only got the misfire code after changing the injectors.



 

This is now ringing a bell actually... I remember someone doing this and then disappeared.

Can you check the number of holes on the injector nozzle?

[Carolyn]

The injectors had the same part number but different numbers stamped on the opposite side.

Not sure on the misfire as Iv not touched the plugs for weeks and I have only got the misfire code after changing the injectors.



 

This is now ringing a bell actually... I remember someone doing this and then disappeared.

Can you check the number of holes on the injector nozzle?

As I recall when we did the valve clearances on Helen's car, it reported misfires while it re-learned the valve timing, then they went away.

[M.Dub]

I'll dig the old injectors out the skip later and post a pick.

I'm just gonna drive it for a few days see if the misfire clears itself.

[carolineasb]

Did the previous owner say why they rebuilt the engine? Seems odd that they had to rebuild (which is usually down to possible oil burning and then the subsequent breakdown of the precats) but then didn't change the manifold and thus remove the precats?

[M.Dub]

No he never said, I asked him if he had removed the pre cats when I viewed it but he dint believe the whole pre cat story and thought the issues the roadster had was down to something else, he never said what he believed it was tho.

Fist thing I did was put a stainless system on it. The cats to be fair were in good condition from what I could see.

Think he just bought it as a projects
as he said he's been rebuilding engines a long time.

[M.Dub]

The old injector numbers

[M.Dub]

.

[shnazzle]

.

Thought so... 


We've had a discussion about these on here once before. 
Supposedly "better" because they had a slightly higher flow and "better" spray patten.
I remained unconvinced... And now vindicated.

[M.Dub]

Bloody hell!!!

Guessing the injectors are rubbish?