Help with Cobra Intake on GEN I

5

57TBird

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I need some help with a particular problem I'm having with assembling my Cobra intake on my GEN I.

I never really liked how on the Cobra intake an electric motor holds my IMRC plates open, and know they tend to fail, so I decided to use my GEN I vacuum controllers with my Cobra IMRCs. I set them up as follows...

First, I put the cobra plates on the Mark controller rods, then I put the cobra IMRC adjusting screw stops in stock location, after cutting off what wasn't needed.
finally, I modified the vacuum IMRC controller brackets and mounted them upside down, actuating the rods from a hole drilled on the opposite side. This closes the IMRC plates under vacuum, and they open up when vacuum is released, just as in the GEN I intake.
Finally I adjusted them to Service Manual specs. They now fully close at about 12lbs of vacuum, and open when vacuum is released.

I've attached a picture of the IMRC setup with the vacuum lines and one of the mocked up intake. Note from the pictures that I've also added a coolant line from the drivers side water jacket, steeda underdrive pulleys and timing adjuster, 160 AMP alternator, accel coil packs, and I've powdercoated most everything with a clearcoated aluminum finish. If the pictures don't show they are on the second page of my Cardomain web site, below.

http://www.lincolnsclub.org/forum/user_files/490.html

http://www.lincolnsclub.org/forum/user_files/491.html

My problem is where and how to route the vacuum lines on the cobra intake. I have the GEN I IMRC vacuum lines, with 3 small connectors and 1 large connector. 2 of the small ones go on the two vacuum actuators on the IMRCs. I have no idea where the 3rd one goes (fuel pressure regulator maybe???)
The large connector goes to a vacuum port on the intake; It will just reach the back one, on the passenger side.

I'm not sure if there is some controller or solenoid that I am missing to release the vacuum and open the IMRCs at the right RPMs.
As I'm working with an unused crate engine, I don't have the original
setup to work backwards from.

I've been told that you can just hook to the intake, and that the vacuum drops after 3K RPM, which opens the IMRCs. I'm not completely convinced that it will work, because if there is any vacuum at all, the IMRCs wouldn't open all the way.

The Service Manual mentions both a "secondary air injection control solenoid vacuum valve" and "IMRC control solenoids", which I don't have and can't find a diagram of. Are either of these what I may be missing?
Also, if this is what is needed, where would I connect it/them to the manifold and how does it/they plug into the PCM?

Note that I will delete the EGR and the fuel canister vapor purge (not needed as this is going into a 57 TBird = no emissions requirements in GA). I'm also not using any manifold vacuum for my brakes, as I am installing a hydroboost unit from a late model mustang.

Any help/insight and especially pictures of a working setup are appreciated.

Thanks.
 
RE: Help with Cobra Intake on GEN I

1st Gens have a separate RPM controlled valve that is open under 3k rmps (more or less) and closed above, restricting vacuum to the IMRC actuators and closing the IMRCs via the springs. The valve is mounted usually on the driver's side valve cover, right next to the EGR valve.

If you hook it up straight to vacuum, any time you go WOT (no vacuum), the IMRC will open, even at low RPMS(under 3k). That's not the way they were designed to work.
 
RE: Help with Cobra Intake on GEN I

That's exactly what I'm looking for. You don't have a part number for that valve, do you?
Anyone have a picture of the valve and how it hooks into IMRC vacuum tubes and the engine harness?

Also, it looks like my picture links above aren't working. Just go to my cardomain site link (below), and go to page 2. The 3rd picture is the intake (mocked up). The 4th picture shows how I mounted the IMRC controls.

Thanks.
 
RE: Help with Cobra Intake on GEN I

Looking at your pictures, it's pretty clear what you're missing: there should be a bracket bolted to your left rocker cover with two electronic vacuum solenoids on it-- the EVR and the IMRC control solenoid. If you've still got them around, you're laughing, but I'll talk to my parts guys on Monday and get you Ford part numbers anyway.

Here's what you'll need to make them work:

VACUUM-- Both solenoids need manifold vacuum to their lower nipples. You're going to have to run that source vacuum through a "tomato juice can" so it's not gone at WOT. The EVR's upper nipple goes directly to the EGR valve. The IMRC solenoid's upper nipple must feed through a tee to both IMRC actuators.

ELECTRICAL-- Both solenoids are commanded outputs of the PCM. They share a common keyed power source and the PCM controls them through ground side switching. The EVR's control is from pin spot# 33 on the PCM's 60-pin connector, and the IMRC's control is next to it, spot #32. In '93-'95, this was a light green/black stripe wire. When you wire them up, keep in mind that the solenoids are NOT polarity sensitive.

That's a truly impressive project you've got on the go!!! I'm glad I could help on something like that. (I'll get back to you with part numbers.)
 
RE: Help with Cobra Intake on GEN I

Your right. I'm missing the vacuum solenoids for EGR and IMRC. I will definitely need the part number for a GEN I, as they did not come with my engine. I might not need the Juice can, as at WOT I'll go over 3200 rmps almost instantly with 4.11 gears; but I may try it both ways to see which one works out the best. Now I only have a few followup questions....

1.) Would the soleniod mount directly to the Cobra intake where the Cobra EGR solenoid is (drivers side, front of upper intake, right beside the IAC)?

2.) As I'm deleting the EGR, I would mount the solenoids at the stock cobra location above, then block off the EGR one, leaving only the IMRC solenoid operational. Does anyone know if this will cause problems? I will be using a 4-bank custom chip, so I'm assuming it can be programmed for this.

3,) Finally, There are the 3 little connections on my current vacuum harness, they look like this...

----------------* IMRC 1 (small connector)
|
---------------* IMRC 2 (small connector)
|
|
|---------------------* ? Third small connector
|
0 Large Vacuum supply connector

(A)If the vacuum supply goes to the solenoid, does the third go to
the fuel pressure regulator? Or...
(B) Does the 3rd small one go to the IMRC solenoid, and the larger vacuum supply goes straight to the manifold?

If someone with a GEN I has their beauty cover off, maybe they can check and see which of the above is the correct way.

Thanks,
 
RE: Help with Cobra Intake on GEN I

Thanks again,

That diagram is exactly what I needed.
It looks like I'll have to add everything on the right of the bottom picture, between the Intake and The IMRC actuators.

Parts remaining...

The check valve,
Vacuum reservoir,
Intake Manifold Runner Control Solenoid,
and some more misc. vacuum tubing.

Does anyone have the specific parts numbers or any spares I could buy of the check valve, vacuum reservoir, and control solenoid? I couldn't find any of it on the Rockauto site.

Once its done, I'll be sure to take pictures. I'm sure others may want to do the GEN I to cobra conversion with vacuum IMRC controllers vs. the electronics. There is an definite advantage to having them stay open if they fail, versus staying closed.
 
RE: Help with Cobra Intake on GEN I

Vacuum reservoirs and check valves should be easy enough to find. Any old check valve or reservoir should work, it shouldn't matter if it's specifically for an IMRC system. I know my rommates turbo spirit uses all kinds of check valves in the vacuum lines.
 
RE: Help with Cobra Intake on GEN I

OK, Mike, here goes!

E8AZ-9H465-B -- The IMRC control solenoid
FOTZ-9J459-A -- The EVR (if you have a change of heart about your EGR)
DY260 -- the one-way check valve you see in Driller's diagram
D5TZ-9E453-A -- Ford's big black juice can. Really, any reservoir will do, there's so many possible shapes and sizes.
F3LY-9H472-A -- the mounting bracket. It's obsolete from Ford, but so what? You can put the solenoid(s) any place convenient.

I'm taking for granted you're using a '93-'95 EECIV PCM for this, so pin positions will be correct.

Finally, you asked about "secondary air". Whenever you see that in Ford publications, they're referring to Thermactor (GM calls it A.I.R.). This is pumped fresh air injection to the exhaust system to help the catalytic convertors burn off HCs. You certainly won't be bothering with that!
 
RE: Help with Cobra Intake on GEN I

Thanks Frankie,

I just ordered the parts tonight.
I'll take some more pictures when its done.
 
RE: Help with Cobra Intake on GEN I

Whoah, Mike! You're too fast. I have another option for you.

D6TZ-9E453-A.

The Mark VIII's inline reservoir is a tiny thing, just 1"X3", but obviously sufficient. It's obsolete from Ford, so my parts guy gave me a number for a generic one. Well, today I worked on a '97 Escort that had one in the line going to the EVR that's identical IN EVERY WAY, just a different part number. It's available.

I think this little reservoir will probably look and fit better than a big one hanging somewhere under your hood.
 
RE: Help with Cobra Intake on GEN I

Thanks again Frankie,

I was able to change my order to the smaller vacuum reservoir from Ford Parts Network. I've yet to get confirmation that the any of the order is fulfilled. I'll take lots of pictures of the setup, when I get the parts.

Also, two final follow up questions.

1.) Should I use the Cobra IAC or the Mark VIII, bolted to the cobra position. They look almost exactly the same. Will the Cobra one work with no problems on a GEN I?

2.) PCM Options: I have both a W3Z3 (1993) and a Z4H0 (1994) to choose from. Which one do you think would work best with an EGR delete, 350+HP J-MOD with 3500 stall, 4.11 Gears, Cobra Intake, headers, 180F thermostat, and no cats?
I already have a 4-bank SCT chip, I'm just waiting to get the engine and tranny done, before I have it flashed. I'll use the chip to set the shifts between 6200 & 6500, bump the rev limiter to 7k (or above?), and get rid of any max mph limits.

I've been told that the 93 is preferable, but I want to get as much information as possible, before I send out the PCM and chip.

Thanks,

Mike - "soon to be" Modular powered 1957 T-Bird. http://www.cardomain.com/id/57tbird
 
RE: Help with Cobra Intake on GEN I

either PCM should work, you'll need a tune either way. EEC V (97-98) would probably be preferable as far as tuning goes, but it would probable create a wiring nightmare.

Either IAC should work.
 
RE: Help with Cobra Intake on GEN I

Hi, Mike!

Consider those IACs interchangeable. As the PCM opens and closes them, it takes feedback information from CKP for RPM and MAF for load (primarily) and adjusts idle speed accordingly.

I've never seen actual Ford documentation to prove this, but the Ford grapevine and this website say that '93 PCMs had slightly better timing and fuel delivery curves than other years. So what? You're going to get yours tuned to exactly your needs.

Finally, don't in your wildest dreams think of using a 2nd Gen PCM! OBDII is a fully integrated multipexed network in which all modules trade information and function as a single entity. There's a long, long explanation, but here's a couple of examples to show you the kinds of situations you'd have to deal with:

The wheel speed sensors provide vehicle speed information to the ABS/TC module. It then shares that data with the HEC (Hybrid Electronic Cluster) for speedometer and the PCM for load/fuel delivery/shift calculations.

Second Gen Marks are equipped with PATS (Passive Anti Theft) and the PCM needs to recieve a valid signal from the HEC, which contains the PATS hardware and software, indicating that a programmed key is being used, before it will come alive.

The PCM also has to recieve key position information from the SCIL (Steering Column/Ignition/Lighting) module before it will engage starter circuits.

And the list could go on and on and on....

Here's a story from one of my other posts.

"Let me illustrate the beauty of multiplexed OBDII networks. Last week I worked on a 2003 Windstar, and the customer's complaint was: "The interior light works fine when I open my doors, but does not work at all when the engine is running."

What would you think is wrong? Let me give you a hint: if a door is left ajar and the customer drives the vehicle anyway, the interior lights are shut off at 8mph to prevent a visual distraction for the driver.

Vehicle speed is a calculated average of all four ABS wheel speed sensors, biased to the drive wheels. This inferred signal is sent to the HEC (Hybrid Electronic Cluster) and is then split and sent to the PCM for shift control and other things, the ACU (Audio Control Unit) for speed dependant volume, and the FEM (Front Electronic Module) for speed dependant interval wipers and Interior Lighting control, among other things. If the FEM cannot see a clean wheel speed signal from 0mph up, it disables the interior lights.

This vehicle's interior lights did not work because there was an internal defect in the ABS module!!"
 
RE: Help with Cobra Intake on GEN I

I definitely agree with you on staying away from OBD II.

As it is, I will be splicing a Mark VIII engine, engine bay, and fuel harness to a Mustang dash harness, and a 57 TBird chassis, lights harness, and dash controls. Plus I'll be throwing in a custom stereo, video, and navigation system. With all the custom wiring I already have to do, using the simplest Mark VIII system is the best way to go. I had already decided not to go EEC-V just because of PATS, but I didn't know the systems interdependencies were that complex, which makes it even worse.

My next big question on this forum will probably be to solicit feedback on how the chip should be flashed, but that will have to wait until I finish the engine, JMOD the tranny, and get all my harness mods sorted out.

Thanks again for all your help,
 
RE: Help with Cobra Intake on GEN I

Mike, I really have to compliment you. This is really a fantastic, unique project you've got. You certainly seem to be making excellent choices, right from the initial idea of taking a true classic and blending in the comforts and sophistication of modern technology.

Over the years, I've helped restore a number of older Fords (to original type condition). While I respect them for their beauty and historical value, I cannot help but be struck by how primitive they were. Braking is poor, handling is worse, steering is awful, creature comforts are nil, compared to even low-budget grocery-getters of today.

The T-Bird will be the best of both worlds.
 
RE: Help with Cobra Intake on GEN I

I would like to thank everyone for your help...

The completed engine pics are now on my cardomain site, page 2.
There's also some new pictures on page 3 of how the shortened rear end, wheels and tires, look mounted up.

I put in two detail pictures for how I did the vacuum IMRCs with the cobra intake.

One shows how I did the vacuum controls. If you look at the picture and go from left to right, you'll see the check valve, a small vacuum canister, and the vacuum control valve, all tucked in beside the cobra intake.

The other is a closeup of how the vacuum canisters were mounted upside down, with new holes drilled in lever on the IMRC rod. I also kept and modified the the cobra lever stop assemblies.

Thanks again. Since I've been pretty successful with DIY powdercoating, I'm going to ceramic coat my headers myself, too. I'm using the same stuff jet-hot uses; I'll post new pictures when I'm done.


:7
 
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