1989 Town Car HO Conversion running rich

[OVERKILL]

OK, I've got a few ideas in my head about what might be wrong, but I will provide as much detailed data as I possibly can so that if anybody else has experienced a similar issue, they might help me out.

Overview:

Well, I did an HO conversion on my 1989 Lincoln Town Car using the following parts:

Heads: Stock Mustang E7 heads, milled an unknown amount with new valves and springs
Intake: 1996 Ford Explorer intake with EGR provision
Cam: 1988 stock Mustang HO camshaft
Rockers: Cobra 1.7 roller rockers, new Comp Pro Magnum pushrods
TB: Stock 50mm Town Car TB for now until my lightning EGR spacer arrives.
ECM: Lincoln Mark VII LSC ECM to retain Cruise Control
Injectors: Stock 19lbs injectors from my Mustang


So, heads were installed, pushrod length was obtained using a home-made adjustable pushrod and checked with a dial caliper. New timing set was installed, and the ACT sensor is relocated to the airbox after the filter. When first setup, I used RTV (big mistake) instead of a gasket for the EGR spacer, and it blew out, making the car not idle and it consumed a vast amount of exhaust. Timing is set to 10 degrees initial, but it WAS severely retarded for a short period of time, upon first fire-up until I could get a light on it. This DID result in glowing manifolds for a short period of time, which tipped me off to a timing issue. This was during the time the EGR spacer was leaking, so multiple problems caused some confusion there.

Ignition system consists of a newer cap and rotor, MSD 8.5mm Super Conductor wires, and MSD Blaster TFI coil. Plugs are gapped at .045

The car would idle once the EGR spacer issue was resolved (using a stock used HO gasket right now, it isn't leaking, I had it off yesterday to check) but its VERY rich at idle, and thus "hunts"

Upon initial fire-up, it runs fine, but quickly develops a miss which is only noticeable at idle under load, as soon as you are on the pedal, its fine.

Vacuum varies slightly, but I cannot seem to find a vacuum leak, besides the master cylinder, which causes the idle to come up noticeably once you hit the brakes. Otherwise, besides when you hit the brakes, I don't think its leaking, and thus, not causing my idle issue.

The plugs are BLACK, and I've tried two different sets.

I have tried two different MAP sensors as well.

Codes tell me its rich. That's helpful, as its obviously rich.

O2 sensors are only a few months old, but I'm wondering if I cooked them when the timing was retarded.

Injectors have a LOT of mileage on them, they are out of my Mustang and have been sitting for over a year in the trunk of the Lincoln Smiley

So, driving around, the car works great, its got lots of power and runs smooth. When you pull up to a stop sign it will run fine for a bit then start to miss, then start to surge, you touch the gas, it will stop, and then a few seconds later, start to do it again. Its quite annoying. I have the idle set a little higher, because, if its not set up, the car will just hunt and surge until it stalls. This is a band-aide solution, but since the car is my daily driver, it has to suffice for now, until I get the rich issue sorted out, which I'm sure will fix the idle issue as well.

So, should I try different O2's?

Anybody else had a similar experience and can share some light? Its 2 degrees out, so working in the car in the driveway gets quite bothersome quickly.

Any help would be appreciated.

Thanks.

-Chris

[mrltd]

I'd prolly think the lack of air entering the engine from the 50mm TB would cause the problem.

The ECT is another cause of rich condition and poor idle.

The ACT location might also be throwing the A/F off due to the signifigantly cooler air at the airbox, compared to the intake manifold location that the ECM is programmed for.

Have you pulled any codes?

[OVERKILL]

I'd prolly think the lack of air entering the engine from the 50mm TB would cause the problem.

The ECT is another cause of rich condition and poor idle.

The ACT location might also be throwing the A/F off due to the signifigantly cooler air at the airbox, compared to the intake manifold location that the ECM is programmed for.

Have you pulled any codes?

The codes tell me that both O2's are reading rich, that's about it

Lots of the Mustang guys have moved the ACT to the inlet tract with no adverse effects that I know of, so I wouldn't THINK that's the issue. The ECT is the same from my old intake, so I would assume its working. It throws an ECT code if you try to run a scan when the engine is cold, and then the code goes away if you run it when the engine is warm (the correct way) so, that would lead me to believe the ECT is working correct. It worked fine in the previous intake..............

And I wouldn't THINK (though I COULD be wrong) that the 50mm TB would cause issues at idle, when the engine is demanding the least amount of air......................But of course the ECM THINKS its a 60mm TB...........

[mrltd]

How's the fuel pressure? Fuel filter been replaced recently? Clogged filter on mine caused all kinds of issues.

The sensors can still read in "OK" but be off enough to cause the A/F to be off. Being that rich, it'd think there are other issues.

[OVERKILL]

I'm thinking there are other issues too

The fuel pump is out of my 'stang, its a 155lph BBK (walboro), the filter is a few months old.

[mrltd]

Might have kinked the return line when you pulled the tank. Prolly want to check the fuel pressure.

[OVERKILL]

The tank was changed last year as was the pump (the stocker died) so none of that has changed since way before the HO swap............... I will take a close look at the return line near the motor tomorrow (its getting dark out) but I wouldn't think I squished it or anything.

[mrltd]

Wierd...

[OVERKILL]

Tell me about it! I have to drive the thing!

[turbo2256b]

Try moving the ECT back to the manifold. If I REMBER CORRECTLY IF ITS READING RICH CODES its running lean if its reading lean its trying to richen it. Plugs can be burned black because its lean as well as rich and black.

[OVERKILL]

Try moving the ECT back to the manifold. If I REMBER CORRECTLY IF ITS READING RICH CODES its running lean if its reading lean its trying to richen it. Plugs can be burned black because its lean as well as rich and black.

I can't move the ECT, the reason its in the airbox is that when I installed the lower intake, I didn't have a big enough tap to tap the boss on the lower intake to take the sensor, because of course the explorer intake has the boss, but its not drilled or tapped. Regardless, there are enough mustang guys relocating it to the intake tract that if there WAS an issue, I'm sure I would have read about it by now..........

I'm thinking it has to be something else, its definitely rich though, you smell major fuel and the exhaust is dark coloured. Its not black, but its dark grey.

[gadget73]

Wonder if one of those injectors isn't shot and leaking fuel. Are all the plugs equally as dark, or does one seem darker than the other? If you pull the vacuum hose off the fuel pressure regulator, does fuel come out? What kind of regulator, stock or adjustable?

[OVERKILL]

Wonder if one of those injectors isn't shot and leaking fuel. Are all the plugs equally as dark, or does one seem darker than the other? If you pull the vacuum hose off the fuel pressure regulator, does fuel come out? What kind of regulator, stock or adjustable?

I could swear that one is darker than the others, #6 I think.

The plugs are all pretty dark though...........

If I pull the vacuum hose, no gas comes out, and the regulator is stock.

I've put TWO containers of injector cleaner in it tonight, we'll see if that helps. If not, I've got an entire other set of injectors I could try that probably have half the mileage these ones do. The REASON I used these ones is they came out of my Mustang, so they were known good but of course have been sitting for quite some time.

[OVERKILL]

::Small rant::

The frustrating part about this is the aloofness of the issue.

The Mustang, with far more mods, took to these things so candidly, and without issue. Its very obvious why people switch to MAF; its so much better at hiding underlying issues.

I've read most of the GFUB, understand the EEC-IV strategy and logic quite well, and I would THINK that with that knowledge, this would be very simple to figure out, yet its not.

Is it because its freezing out and I don't want to work on the car? possibly.

Is it because the Capri is 20ft from the Lincoln, its not my DD and I'd rather work on it? Yeah, that too.

Is it because I'd like this problem to just fix itself, since it shouldn't exist in the first place? Yeah, a little bit of that also.....

It was such a SIMPLE swap of known-good parts, and that is what aggravates me so. The fact it has the audacity to act like such a bitch after I've spent this sort of time and money on her....the nerve!


I could swear it started running a bit better tonight after the two kegs of injector cleaner, bu that could just be me wanting it to be running better. I'll know for sure tomorrow I hope.

[gadget73]

I rebuilt a Mark VII motor for my car. When I pulled it, it ran like a dream with 120k. Now with all new guts it doesnt make the power it should. Trust me, I understand the annoyance in all this.