rough idle rich idle

[smiffy 33]

Hi guys/girls got a idle problem with my 33 1.7 16v. I've had the car about 5 months now before that it was stood for about 6 years and started up now and again. The issue I've got and always had is that it runs really rich on idle and pops and bangs when I lift my foot of the throttle. And sometimes when pushing it hard and then letting off it seems to run rough like its only running on 3 cylinders. I decided to have a look at it the other day, I took the plugs out (which took an age) and they were black (due to over fueling probably). Cleaned them back up and put them back in. Started it up and still ran rough. Read up on a couple of threads on AO and prodeced to clean the idle control valve. Did that with some carb cleaner, put it back in and it wouldn't start. Disconnected the electrical connector and it started but ran rough again. Getting on my tits now. So I disconnected the airflow meter a and no difference. Spoke to a few peeps that I know and can't remember what they said at least on here its written down. Does the air flow meter need changing or some sensor on the throttle body?

Don't know if its significant but when idling 1 cylinder doesn't seem to fire (felt the exhaustg pipes and 1 is a lot cooler than the rest. But when driving it pulls great with no power loss.

I'm really confused please help pleaseeeeeeeee

Thanks leigh
PS sorry for the long winded post

[PETROLHEAD]

Hi leigh, hmm, annoying grumbles indeed

As you already said, black plugs = rich running, but its not enough, we dont yet know if its ruch in general of just at idle if low revs, without doing plug chop type testing, totally impossible in a 16v though except for checking the easiest pkugs over and over again which would be pointless.

The process I would try leigh, would first be to check the balance of the throttle bodies opening from the linkage, firstly visible and then with vac gauges if you can get a reliable idle to work with.

Air flow metres are testable from their input and output voltages. I dont have the exact figures to hand but if you get a wiring diagram to show the connections of the plug, you can meter for input voltage, and then output voltage, which normally varies from around 1v at idle and should smoothly climb to around 5v once the flap is full open.

If you can prove these two issue first, we can move to the next stage after that leigh.

A second afm to plug in and try is always a very simple and quick check if you can source/borrow/blag one?

[SteffenJ3316V]

Yes try a different AFM. They do tend to fail now with age and people trying to improve them

[smiffy 33]

Cheers guys well getting a phone call in a minute hopeing I can borrow a AFM to try. Need to sort the idle control valve I knackered up too. Gonna give it a good blow with some air. Forgot to mention that the car was used as a track/race car before so god knows what's been messed with.

How easy/expensive would it be to convert it to carbs? Would I gain any more hp /torque?

Cheers again

[PETROLHEAD]

How easy/expensive would it be to convert it to carbs? Would I gain any more hp /torque?

Cheers again[/quote]

I've assembled a kit over some time that will fully convert a 16v efi engine to hi performance carbs and programmable ignition, and I totted it up the other day for a potential buyer interested in doing the same,

It was 1200 quid!

Although, its a superb kit, dellorto 45's, manifolds, trumpets, filters, tps, omex etc etc its a lot of money, BUT, it does mean that yes you will lose all the restrictive bit's from the stock inlet system, yes it will make more power and torque than stock, and you will have much more control over stock of course, assuming that they are assembled and set up correctly.

If I can help supply you with anything to try and sort it, feel free to holla leigh.

[smiffy 33]

Wow 1200 if I wasn't just about to buy a GTA I might have seriously thought about that.

Hopefully going to see Alex this coming Saturday to swap a couple of things over and pick up a sunroof that he's got. Will update any new developments.

Leigh

[NEG]

Does this type of 33 have a Lambda sensor? If so it could be a cause of rich idle mixture...

[smiffy 33]

No lambda sensor or cat its a 1990 model.

[smiffy 33]

Right I've changed the coolant temp sensor and it idles better, didn't at the start but the revs picked up and seems to idle better. But the car still won't start with the idle control valve connected. Then I found out the slave cylinder is leaking so I need to change that as well

[Veesix75]

If its the clutch slave on the gearbox, there have been new Delphi ones on eBay for £20 recently.

The one fitted to a 156 V6 is the same as a 33/sud

[smiffy 33]

If its the clutch slave on the gearbox, there have been new Delphi ones on eBay for £20 recently.

The one fitted to a 156 V6 is the same as a 33/sud

Thanks

[smiffy 33]

How easy/expensive would it be to convert it to carbs? Would I gain any more hp /torque?

Cheers again

I've assembled a kit over some time that will fully convert a 16v efi engine to hi performance carbs and programmable ignition, and I totted it up the other day for a potential buyer interested in doing the same,

It was 1200 quid!

Although, its a superb kit, dellorto 45's, manifolds, trumpets, filters, tps, omex etc etc its a lot of money, BUT, it does mean that yes you will lose all the restrictive bit's from the stock inlet system, yes it will make more power and torque than stock, and you will have much more control over stock of course, assuming that they are assembled and set up correctly.

If I can help supply you with anything to try and sort it, feel free to holla leigh.[/quote]

Hi mate are these still available?
How hard is the conversion to do? How does the wiring from the bosch ecu connect to the omex etc? Sorry for the questions.

[PETROLHEAD]

Hi Smiffy


I didn't really make any great effort to sell it all so yes i still have everything.


I sort of made my mind up that i would use this route myself afterall, but i could still be tempted out of it



as for connection to the stock ecu, you don't really, other than blagging the power supply etc , the omex 100 unit takes care of all ignition and timing, and the carbs obviously the fuelling, so the only job left for the stock electrics is control of body electrics such as lights, starting, windows etc, no longer anything to do with the running of the engine.

does that help smiffy?

[smiffy 33]

Yes mate it does thanks