HO swap question:do I have the wrong cam?

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HO swap question:do I have the wrong cam?

April 05, 2007, 07:29:08 PM

Ok I got the car running, sort of. We started the car today with the stock 88 SD 5.0 SO computer and it actually ran ok, even with the 1-5-4-2-6-3-7-8 firing order. Now after we moved the car around so we could change the computer and firing order the car wouldn't run. I changed the computer to a 1989 Mark VII computer and the firing order to 1-3-7-2-6-5-4-8 and the car wouln't turn over. It just died. We put it back to the SO firing order and it ran fine. WTF? We didn't change any injector wiring at all. I don't know if A) this thing has a roller cam with a SO firing order (it should have a Comp 266HR) or B) I some how have a SO Mark VII computer. Any ideas?

HO swap question:do I have the wrong cam?

Reply #1 – April 05, 2007, 07:39:20 PM

When I get home I'll post the part number off my Mark computer for you to compare. That shouldn't be the problem though.

Maybe there's something wrong with the computer. I know I tried two different MAF comps before my car ran after converting it.

If you're truly concerned about the cam, talk to the guy that built the motor. Make sure he installed the correct cam. You wouldn't believe the number of mechanics I've talked to that don't know the difference between an SO and HO motor.

HO swap question:do I have the wrong cam?

Reply #2 – April 05, 2007, 08:46:11 PM

sounds like you have the old school 289-302 firing order in your cam to me, instead of the 351W 5.0LHO firing order.

check with the engine builder or call the cam companies tech line and ask them what the firing order should be on that cam.

HO swap question:do I have the wrong cam?

Reply #3 – April 05, 2007, 09:19:10 PM

I have comp # E9SF-12A650-SA
That probably doesn't help at all but meh.

HO swap question:do I have the wrong cam?

Reply #4 – April 05, 2007, 10:28:26 PM

I think it has the HO firing order but the computer is wrong. I know for a fact that a HO will run with a SO firing order just badly (don't ask why). If I wire it up for the HO pattern with the Mark VII computer it will run for a second or two and then die. If I run it with the Mark VII computer and the SO firing order it will run ok but has py power. It feelt stronger with old motor. Even if I had a SO 302 roller cam it should feel stronger because of the GT-40 heads. I think that I have a SD 5.0 SO Mark VII computer. I know there is a 88 HO Mustang at the wreakers and I'm going their tomorrow to grab the computer. I'm hoping that works.

HO swap question:do I have the wrong cam?

Reply #5 – April 05, 2007, 10:29:56 PM

Mine starts with E7SF so their is a good chance that because it's an 87 it could be a SO computer.

HO swap question:do I have the wrong cam?

Reply #6 – April 07, 2007, 05:45:25 PM

So it turns out I have a SO firing order cam with the HO grind. Ie the cam is the same as a HO cam but with a 1-5-4-2-6-3-7-8 firing order. So being that the 88 Mustang EEC fires the injectors at a 1-3-7-2-6-5-4-8 firing order the car runs but I'm betting it's down on power. I think this will **** up the engine at some point. I'm going to make the engine guy pull the cam and put the right one in. Good idea right? I thought the guy would put the right cam in it being that he does a lot of hi-performance engines for people. I told him I was putting it in a T-bird and he had a custom cam ground that had the same specs as a HO cam but with a SO firing order instead of just using a HO cam:hick: .

HO swap question:do I have the wrong cam?

Reply #7 – April 07, 2007, 05:54:40 PM

Yeah, make him put the right one in there. Hopefully he isn't going to charge you for this. Afterall, it was something he did without speaking with you first.
Don't you love when people ASS-U-ME :hick:

HO swap question:do I have the wrong cam?

Reply #8 – April 07, 2007, 11:13:05 PM

Ah...the joys of just getting a regular HO cam :D .

Seriously, though, unless you informed him of the firing order difference, he probably just set the cam up to run in a Tbird like you had said. But, I'm guessing you told him about everything before hand...right? If not, I could easily see how he could have just set it up for a Tbird. Sounds to me that he just did what you had asked, assuming that what you said in your post is all that was said.

HO swap question:do I have the wrong cam?

Reply #9 – April 08, 2007, 01:03:40 AM

Sounds Like you have it figured out...

as for Comp #'s if you want to know what you have for sure here is a list

http://fordfuelinjection.com/?p=17

HO swap question:do I have the wrong cam?

Reply #10 – April 08, 2007, 01:16:25 AM

Still got your SO computer? I'd put it on with an adjustable regulator and then do a couple of dyno runs to see what happens.

If you're dead set on swapping that cam out I'll buy that other one from you. There's a few SO 5.0's around here I could pick up for cheap.

I'd love to have essentialy an HO with the old style firing order and 19 pound injectors running on an SO computer

HO swap question:do I have the wrong cam?

Reply #11 – April 09, 2007, 10:37:45 PM

Ok so the engine builder is replacing the cam free of charge. He said it was his fault and he's going to make it right. So I have to drop off the car at his shop next Monday and I'll get it back by that Friday the 20th. The rest of his work is top notch and he was very good about fixing the situation. All in all I'm pleased with the way he's handeling it.

Quote

If you're dead set on swapping that cam out I'll buy that other one from you.

I'll see what I can do;)

HO swap question:do I have the wrong cam?

Reply #12 – April 10, 2007, 02:43:21 PM

Sounds like he's a good guy to be dealing with :)

HO swap question:do I have the wrong cam?

Reply #13 – April 10, 2007, 03:16:13 PM

Quote from: kingcars;139215

Sounds like he's a good guy to be dealing with :)

My thoughts also. Mistakes happen, what will one do to make them right is what matters. If I ever move to Chicago and have a motor built (not likely) I would want his name.

HO swap question:do I have the wrong cam?

Reply #14 – April 11, 2007, 01:25:37 AM

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I'll see what I can do

k, just lemme know when you're ready.