Hi,

I found this example hidden in a local garage for last 15 years.

Got it out, cleaned the tank, new oil, new gas filter, injectors ultrasound cleaned with new filters, o-rings.

It ran in beginning and than after a couple of minutes sputtered and flamed out. Bad O2 sensor, replaced.

Than I fixed the obvious issues, some minor rust and did some upgrades (3.5 lift, 31-s, re gear to 4.88, TC drop, NiftyShifter, TB bore out by DIY ). Actually I enjoy riding it - except:

- it seem to run a bit rich. I always smell gas when running and walking around it
- idle is a bit high - and shifting up and down, between 750 to 1.200 rpm. No obvious reasons. I did fins some vacuum leaks and fixed them. I re calibrated TPS and later replaced it as itseemed to be off. But did not fix the issue
- obviously I have some minor exhaust leak. I smell fumes inside after riding for more than 30 minutes.

Now to questions: any good method for finding vacuum leaks? Most common culprits? What would you do?
Any other culprits for shifting idle?

 

Vacuum leak was my first thought.

https://www.youtube.com/results?sear...+leak+on+a+car

Running rich could be injectors, but you've cleaned those. Still, that might not have done the trick. Usually rich is a bad O2 sensor. Which one did you replace? Did you check the fuse?

Have you checked out the Renix tips at Cruiser54's site?

 

Thank you for the links regarding vacuum leaks. New trick to me.

Regarding Lambda / O2 sensor. Is far as my XJ is, renix flavor - I could find only one. Correct me if I am wrong. Before replacing - engine stalled after a few minutes (after exiting from open loop to closed loop)

What the fuse could cause any of this symptoms? Which one?

Thanks again :-)


Last Wednesday day road trip

 

Got the map connected to the right hole? Original injectors and a faint whiff of fuel can mean a leaky injector. Mine were rusty and starting to weep through the outside. Couldn't find it until I stopped and ppped the hood real quick and saw one wet on the outside.

 

I have two sets of injectors. Went over both, cleaned, rebuilt them with new o-rings, filters... No difference. Did not notice any bad behaviour on the outside. Will flow test them just in case once again, but doubt the problem is there.

I believe MAP is connected correctly. I did not mess with it. Any clear images somewhere to doublecheck?

 

So long as you have vacuum to the sensor, I think it should be good.

 

I found this one - seem to be very informative:
Will check it fully in a couple of days. Ordered new harness so will be a once-over pretty soon.

 

There is a fuse for the O2 heater. I don't know which one off the top of my head. If it's blown, it's the same as having a bad sensor. Sometimes the wiring gets chafed and blows the fuse, then the engine goes stupidly rich.

 

You must have heat to the O2 sensor. Red wire.

check all the intake manifold bolts. They're likely not tight enough as the factory spec was too low.

The hose from the throttle body to the MAP must be perfect.


And, you should visit www.cruiser54.com and complete Tips 1,3,4, and 5 before you do much else.

 

An exhaust leak can cause rich running by fooling the O2 sender that the mixture is too lean.

A smoke machine test can find such leaks.

Dont run rich for long, else the catalyst will melt, ask me how I know. The root cause was a failed egr valve seat.

A scan tool from Snap On, the MT2500 was helpful in diagnostic, suggest you buy one.

https://www.ebay.com/itm/automotive-...edirect=mobile


Also confirm that your fuel pressure regulator is working.

 

Thanks for this input.
I hear a small exhaust tick and also recive nasty fumes in the cabin.
I already have new exh manifold, gaskets and HW, the rest will be checked on the fly.
If I would buy diagnostic tool - I would use Nick's engine monitor:
https://nickintimedesign.com/
It seem to be more capable.
I bought nifty shifter box from him and I am super happy about it. It transformed the old AW4 shifting habbits to the 21-st century DSG feeling. I highly recomend that mod.

The FPR - this was one of the first suspects and performs flawlesly. Pressure is spot on, non return valve holds pressure within limits for several days.

About EGR and CAT:
I got it without cat. I was checking and suposedly EU version was delivered without cat!
EGR - there is no valve. Just a fixed tube between exh port and intake manifold. It looks original to me, not messed with at all.
A comment on EU emission control would be highly appriciated to confirm what I have on my hands.

 

Oh, your in europe. I am very interested in a photo of the tube that is in place of the egr. Please post it, thanks!

If that tube is constantly supplying exhaust gas to the intake, that can be a huge problem. Doing so will really screw up the manifold vacuum level, thus fooling the MPS, and it will also heat the intake air, which will fool the air temp sensor. I found this out when my egr stayed open in effect when its valve seat fell out.

Why not do an old fashioned manifold vacuum test? put a gage on the intake and read what the vacuum does at idle, when reving, etc.... do this on a warmed up motor.

I considered the Nick in Time scan tool, but it was out of stock at the time, and the snap on unit came along, so I bought it instead. either should work for you. my snap on tool also showed poor manifold vacuum, and really hot intake air. of course a vacuum gage and a meter on the temperature sensor can also show that.

anyway Id love to see the euro version of the egr valve.

good luck!