well ive got most of my problems resolved, except 1 or 2 things.

car starts fine, but when first started the idle will go up (like its supposed to) and then it'll go a little lower, like its smoothing out (like its supposed to) and then the engine clicks and the idle drops way low and acts like its missing for maybe 2 seconds, and clicks then goes back up. it does this for a few minutes until i put it in gear, and it will idle low and start missing again, but is ok after i drive it for a second.

not sure if this has anything to do with it, but the engine takes like 20 minutes for it to warm up (on the freeway).

could these 2 issues be related? or is the time that it takes to warm up normal?

 

Could be the thermostat stuck open.

 

I think they are probably two separate issues. I agree with Jim long warm-up times often indicate a thermostat stuck open. easy and cheap to check and fix.

The idle behavior could be many things. What is your idle speed? Should be around 750rpm or so and will drop to around 600-ish when you put it in gear. Does the engine feel like it is misfiring? Does it only do it when cold or even when warmed up?

Here are some easy things to check. There are many others depending on your symptoms.
Inspect and if necessary clean throttle body and make sure throttle disc gap is set to .002"
Check plugs are not fouled and are gapped properly.
Air filter is clean
Check distributor cap and rotor for wear/burn marks.
Measure primary and secondary coil resistance of the ignition coil
Check for vacuum leaks
Inspect and if necessary clean the EGR valve and ensure the passageway to the throttle body is clear.

Cheers,

Allan

 

the idle ranges between 1200 cold, then goes down to like 1000 in park about 750 in drive (still cold). but when warm i got it down to about 650 -750 in drive, but sometimes it will go to 1000 and smooth out down to 600-650 and idle kinda rough.

also it surges on the freeway and hesitates on acceleration.

where is the EGR valve located on the 3.6? im about to go out and give the system a good cleaning, make sure nothings blocked and such.

how warm is my cars engine supposed to get? its about 55-60 degrees right now and it only showed 2 dashes (not sure what that means) when i drove it about 20 minutes ago for a few miles, but during the summer, it always stayed a few dashes below the center mark in the city and cooled off when on the freeway down to 3 dashes.

 

Agree with jimbov8, sounds to me like the thermostat is stuck - it should be at 12 o'clock (dead centre) once she warms up.

The idle may be a separate issue, but the egr port (located directly under the IACV in the intake manifold) tends to get plugged up with carbon. My 94MY had both a stuck thermostat and plugged egr port when I bought the car and replacing the stat and cleaning out the port made a huge difference.

 

like inside of the intake manifold? do i have to remove the intake to access it?

 

or are you talking about the egr solenoid with the filter on it?

 

so the 90+ models have an egr on the exhaust manifold but the 88-89s dont..?

 

On my car you remove the IACV and the port is directly below, inside the intake manifold. When you remove the Idle Valve you can see the egr port. You don't have to remove the manifold, just the IACV.

I'm not sure if early cars have the same setup, check the parts diagram on the Jag Heritage site maybe?

 

ok thank you, i never would have figured that out haha. is that what the egr solenoid is connected to? 1 more question... i took the filter off of the solenoid and pulled the throttle and it started sucking. is that normal? i thought that was a vent?

the previous owner of this car messed with it for over a year, so a lot of things are incorrect, which is why im having difficulties getting this damn thing sorted out. its doing better though

 

I just cleaned the port and that seemed to help the engine to run more smoothly. Didn't really get into the rest of the egr system yet so I can't answer you as to what's 'normal' - but if you search the forum there's a few good posts on EGR.

Yeah, well keep at it. I've had mine a year this month and also had a bunch of things to learn about and fix. If I was in your place right now, the first thing I'd do is get a new thermostat because if she doesn't get up to temperature you'll never get her running right.

 

Just a couple of things.

The EGR system does not operate at idle or WOT. The engine needs to be running between 1000-4000 rpm, the transmission must be in drive and the engine at operating temperatures of above 140F (ie it should not operate when cold).

A simple test for the checking whether the EGR port in the intake manifold is clear, is to put your fingertips under the EGR valve and push upwards while the engine is idling. This will open the valve and allow exhaust gas to flow. If the port is unrestricted, the engine will sputter and just about die because of the introduction of exhaust gas. If the engine does not react, the port, EGR valve or connecting tubing are blocked and should be cleaned. (if you do this when the engine is hot be careful and wear heat resistant gloves as the EGR valve will be hot.)

The EGR can cause idle problems if the valve is not closing fully as this will allow a small amount of gas into the manifold. Often just cleaning the valve with carb cleaner will remove any deposits that are causing the problem.

Cheers,

Allan

 

wow thanks! that makes a lot of sense.

last night i cleaned out the ports to the intake, and im going to clean the egr today and pick up a new thermostat. are there any other areas that could be potential for clogging besides the egr? i cleared out a port that was connected to the crankcase vent tubes already and that seemed to help a lot.

 

ok, so ive cleaned the iac valve, removed whatever casing that is that the iac valve screws into, and cleaned it out. there was a plunger type deal in there that screws in with an allan wrench that was full of gunk so i sprayed some cleaner in there.
cleaned egr and there is 0 blockage.
one thing i did notice while i was poking around was inside the distributer cap, white stuff was stuck to the contacts. ill be cleaning that out tonight.

but also another thing i noticed after disconnecting my battery and reconnecting is that the AC clicks when ever i turn the key to ACC. so i pulled the link box by the headlight and tried it again, no click.

is the ac supposed to click when the ignition is turned to accessories? or does that mean its constantly running?

 

also after i cleaned everything, my idle is at 1500rpm and wont drop until i put it in drive, then it drops down to 750-850??

 

Could be a couple of things.

1. since you disconnected the battery, the ecu will need to learn the stepper motor position. Just start the car from cold and let it warm up at idle. Don't rev the engine. The ecu will adjust the stepper position and you should see the revs come down.

2. You may have altered the base idle when cleaning the ISC. Go through the manual setup procedure for the base idle. Not sure if it is the same as the 4.0 cars but if it is, you should

Switch ignition on and wait 5 secs then disconnect the ISC
Switch the ignition off
Wait 15 secs then reconnect the ISC

Repeat the above twice but on the last occasion do not reconnect the ISC

Then start the engine. the base idle should be between 550 and 600 revs, if not, adjust the bypass screw to bring it in line.

Then switch off the engine and reconnect the ISC

Finally crank the engine again and you should be between 650 and 800 revs in park.

Cheers,

Allan

 

ok, i did what you said but while i was doing it, unplugging the iac valve didnt change the idle at all. didnt drop, didnt rise, nothing. it runs better now, but i thought the car should die or run like crap if the iac valve was unplugged? also, i unscrewed the idle screw and the idle stayed the same. it is now unscrewed to where the stopper on the throttle isnt even touching it, even with both cables completely relaxed.... confused

 

I think we have our lines crossed During the manual setup phase, when I say turn the ignition on, I mean turn the switch to position II not start the engine. The process is designed to help the ecu know where the stepper motor limits are so that it can orient itself.

You don't actually switch on the engine on until after the orientation process. Try it again using the procedure outlined in my previous post.

It does not surprise me that nothing happened when you disconnected the plug when the engine was running as now the valve cannot move, it will just stay in the same place that it was before disconnection. The air supply cannot change if the stepper motor is not working.

Hope that explains it a bit better?

Cheers,

Allan

 

ok well i guess where im at now.. is when i first start it, the rpms are about 1100rpms and then bleeds off down to about 750.. idle doesnt go up and down anymore (very much), definitely not like it used to. is that about right?

 

Yes 750 is good