4AGE Tuning Question ?

[juantonwan]

A few months ago I freshened up my engine (4age 16V) and got it put back together and running. It wasn't running how it should. For example, when going up a hill it would lack power, or choke when you stepped on the gas. I drove it like this for a bit, then on day it was perfect. I am not sure what happened, but it started driving great. It was after a freeze, so I was thinking maybe the cold help seal a air leak. Anyhow, the car ran absolutely perfect for a few months.

The other day my timing belt broke as I was backing out of the drive way. I got a new belt, then positioned the cams in relation to TDC for #1 piston. Intake at 12 o'clock and exhaust at 5 o'clock positions for the knock pins. My cam sprockets also have marks on them that match the metal back plate marks.

I did not touch the distributor at all. So it should be exactly the same as when the car was running perfect. So the cam timing is perfect and the ignition is just how it was.

Problem:

When I run the car, it is acting like it did after I first freshened it up. If I quickly press the throttle, it chokes. Going up hills it lacks power and bogs. The plugs are white, which all these indicate it is running lean.

My question is, what could be the issue? I don't yet have a timing light, but like I said the distributor did not move.

Could the cams be a tooth off? They match the marks exactly where they are supposed to be.

Could a valve be sticking?

Any thoughts or input would be great.

[jondee86]

If you can hook up a fuel pressure gauge, check what pressure you
have in the rail at idle, and when you snap the throttle open. Better
still, if the gauge is portable, drive to the nearest hill and check if the
pressure drops while the car is feeling weak.

Cheers... jondee86

[Bean]

get the timing checked at a garage nevertheless... it's just a 5 min job (don't forget to short out the two pins on the check connector)

also have a look at the back of the plenum... where the EGR goes (I had a leak there once)

I recently fitted a wideband and get quite lean readings at idle I need to check though if I have a small leak at the header or sensor boss as well as my fuel pressure like jondee mentioned...

good luck with troubleshooting and keep us posted with more infos the more we know the better we can help...

[juantonwan]

Thanks for the info.

I shorted the diagnostic terminal and got the following codes: 2 and 8.

The haynes manual says 2 is air flow meter and 8 is intake air temp sensor.

I am thinking it may be a wiring issue?? Because it was running rough, then perfect and now rough again. Any thoughts?

[Bean]

if you have an AFM version (USDM or Swiss/Sweden versino) the air temp sensor is part of the AFM unit - if you have someone close buy you could swap it to see if that works...

PS: if your AFM is realy broken, please don't throw it away - I need still need the plug of it (held into the unit by two screws) http://www.aeu86.org/viewtopic/wanted-af...e29/t/9791

[juantonwan]

Bean Bandit Wrote:if you have an AFM version (USDM or Swiss/Sweden versino) the air temp sensor is part of the AFM unit - if you have someone close buy you could swap it to see if that works...

PS: if your AFM is realy broken, please don't throw it away - I need still need the plug of it (held into the unit by two screws) http://www.aeu86.org/viewtopic/wanted-af...e29/t/9791

Don't have anyone nearby to test it out. Any other way to check it?

I am going to go check the wiring etc.

I think the temp sensor is inside. - As I said it was working great for months after one day I was messing around under the hood. Maybe I bumped the wiring or something. I will play with it.

Any other info would be great.

[Bean]

check the engine manual there is a troubleshooting section where you can measure the different pins on the plug with a multimeter to see if the unit is still ok. engine manual can be found on the web there's are several links in this forum too... it's good to have anyway