I have a question...
Since I replaced the engine in my 83 I haven't been able to get it to run well. It's as if the ignition timing and the injector timing aren't synchronized.
Now I'm wondering if I have the distributor 180 degrees out? Will it run (albeit poorly) if it is?

 

Yep they will, and quite poorly.

I would get right back to basics, and set #1A on TDC on compression stroke, and ensure the rotor is pointing at that terminal in the cap, if not lift the dizzy and set it at that point, also ensure that the adjuster at the front of the dizzy case is fully in the "retard" position, then double check the leads are in the correct sequence in the cap posts. Rotor moves anti-clockwise.

Vac leaks are a bugga on these, as is the integrity of the vac line at the rear of the balance pipe that supplies vac to the ECU.

There could be other gremlins, but starting at the beginning, and systematically doing what is required will sort it quicker than stabbing at all and sundry.

 

Thanks Grant
Strangely, I discovered something today. I had just been running it with down pipes off the manifolds after putting in the motor. This morning I put the exhaust on and...it runs better! I had not heard that these motors needed some back pressure before?
It still isn't right, but it sure is better than without the pipes. I still have some fine tuning to do, but I'm well on my way.

 

Mmmm, waaaaaay back when I used to race cars, some back pressure was better than zero, but it was relevent to how wild the cam grind was.

So I reckon a standard spec engine, designed to run WITH an exhaust system, would be off the boil without one. This leads obviously, to the question we hear regularly about "sports exhaust systems" on our cars, and the fore and against of that scenario. More noise does not always lead to more performance, although it may "sound like" it is more powerful.

 

Okay, back to the drawing board.
It WAS running better..still off, but better and I figured I'd try some adjustments once I got the engine warmed up. Wrong. The more she warmed up, the worse it ran. It's fouling the plugs bad.

 

An '83 would be an HE engine with Oxygen sensors, correct?
With the exhaust off you'd read too much O2 and the sensors would add fuel. As the engine warms the effective mixture would get even richer. Any exhaust leak on a car with O2 sensors will have the same effect. Depending on the exact flow characteristics you could even get reversion pulling in oxygen from downstream on shorter pipes.
I've forgotten if disconnected O2 sensors cause rich or lean condition... but disconnected can also be problematic.

 

Yes it has the O2 sensors, and I wondered if that was a factor which is why I put the exhaust back on before I proceeded any further. I'm not sure if that was what made it run better or if it was the backpressure, but either way it was temporary and it's back to running rich and fouling out the plugs.
The plugs are brand new too. I have to admit that I've never seen such a small spark plug gap before, is this something I should consider changing? Would widening the gap make them less likely to foul?

 

Not sure what you'e already checked but a couple common problems related to over-fueling are the coolant temp sensor and the fuel pressure regulators.

The coolant temp sensor can be check with an ohm meter or, at about $20, it isn't a very painful WAG to just replace it

A fuel pressure test will tell you if a faulty regulator (the left regulator in this case) is allowing excessive fuel pressure. But, even if the pressure is correct a leaky regulator (left or right) could allow raw fuel to be sucked into the engine. RUn the gnine, shut it off, and then pull the vacuum hoses off each regulator. If there's any raw fuel present in the hose, there's your sign.



Nah. Stay with the .025" gap. It's not a problem

Cheers
DD

 

Thanks, I'll give those a try. I did pull the vac lines off each regulator while it was running to see if they had vac and they did, but it also made no difference in the way it ran. I also pulled the plug off the temp sensor and it made no difference either

 

Pulling the vacuum hose would increase fuel pressure but the engine is already running rich so that's probably why there was no difference in running.

Assuming no raw fuel dripping the only other thing to do is perform a fuel pressure test to make sure pressure really is normal





Hmmm. The two wire sensor just aft of the left side thermostat? The engine should have died when you pulled the connector.

I'll have to mull this over :-)

Cheers
DD

 

ah-yup, that was the sensor I pulled. Just for ha-ha's I even pulled the plug off the air-temp on the air cleaner housing..still nothing.
Oh, and I've switched out the ECU and tried adjusting the fuel mix...no change.

 

While you are tearing your hair out, check the vac hose that runs from the balance pipe to the ECU in the boot.

Make sure it holds vac, and/or is NOT blocked. The ECU uses vac to set the fuel supply via injector ON timing, and the LESS vac it sees the MORE fuel it supplies.

I had one that turned up here years ago that had an engine fire, and after all the repairs it ran really rich, if at all, and all the logicical diagnosis failed. The list was HUGE, and mega $$. I noticed a crappy clamp part way down this hose in the engine bay, ????, looked further and a joiner was in that hose, obviously burnt in the fire, removed it to check the rest of that hose, BUT, the hose was full of sticky white goo, turned out to extiguisher foam. Unplugged that hose at the ECU, and blew it out, huge wad of goo exited. Car ran sweet as, and still does today, and is still his daily driver.

Others here have issues with the hose actually splitting where it attaches to the ECU, same result.

 

I haven't got back to work on the car yet, but I had previously checked the vac pressure at the computer and at idle I was getting roughly 17.
If the line to the computer is okay, I could block off all the vac lines coming off the engine and see if that makes a difference. Are there any particular ones I should leave attached?

 

No, I would not go messing with too many things or you are going to loose the systematic sequence that is required to find and fix this thing.

As Doug said, overfueling can be a loooooong list, and the 2 regulators are now suspect, primarily the LH reg, as that is the real pressure regulator, the RH is a damper (symplystic explanation). They can stick, and that will provide excessive pressure to the rail and overfueling. I think you said that when you removed the vac hose nothing changed, so stuck is on my mind.

OR, the fuel return line is restricted and that will also cause excess pressure. That can be as simple as some fool has jacked the car without using the jacking points, and crushed the fuel line, LH side is the return, worth a look. Had that here with one that had just had tyres fitted, both side lines were crushed significantly, car ran like crap.

The throttle TPS is set wrong, or flaky, or out of range, and if the idle "split voltage" is out of spec, the ECU thinks the engine is at some other throttle setting other than idle, and the fueling maps are too rich.

By unplugging the CTS (coolant temp sensor) the engine should die with conviction, so if yours still runs, as I think you said, the wiring to that sensor is suspect, and one of them goes via the TPS, mmmm.

The distributor timing is still high on my list. It just needs to be confirmed it is timed correctly, otherwise nothing else is going to make sense. Too many variables.

 

I already replaced the TPS by adapting a Ford unit as described by Doug.
I've found a suspect wire leading to the temp sensor that I'm going to strip and replace. I'm also going to reset the timing as suggested.
I have a question about the fuel regulators. Are both sides identical? I found a listing for replacements, but they are priced differently and one has a threaded inlet while the other has just a nipple. I don't plan on ordering them until I've fixed the temp sensor wire, but I'd like to know what the difference is.

 

In a word, NO.

They are different as you describe, and are NOT able to used on the other side, as some think.

 

Thanks Grant, I suspected as much, but the listing didn't differentiate them at all.

 

I went thru this a year or so ago. Some of the online catalog listings for the regulators are very confusing and/or inaccurate. Best to go by part number or buy from a Jag specialist.

FYI, if you have a mind to, the right side (inlet) regulator can be removed entirely and never missed.

Cheers
DD

 

really? Then...what's the point of it being there? Seems rather silly doesn't it? Is it some sort of back-up or something?

 

MATE.

British Engineering at its very best hahaha.

The discussions on that are as long as "what is the best oil for my engine".

It is supposed to be a damper, to eliminate/dampen injector pulses from the fuel pump?, the fuel filter is big enough to do that in my opinion, that is, IF, those pulses are such an issue.

Mine has been "gone" for 15 years, and so have most of our group, no ill effects on any of the engines.

Less fuel lines to leak also.