swapped in an E303 cam from Ford racing for a 1997 Explorer, need help

[dani9678]

I just swapped in a cam from Ford as stated above. It has a 5.0 in it and the problem is that it has no power. It has that nice lope now but no power. I checked the vacuum with my guage which is reading 5 inHg at idle. I know that a stock engine is supposed to be between 15 and 25 I believe at idle. The engine is idling at 600 rpms. Will this cam cause the low vacuum reading? When I bump the throttle, the engine seems to pause a second before it accelerates. It doesn't have an instant throttle response. I got a can of brake clean and sprayed around the intake and all vacuum lines to check for leaks but didn't notice the engine respond to it any unless I sprayed it down one of the vacuum lines. I changed the lifters when I changed the cam so I had the intake manifold off but I reinstalled everything correctly and torqued all to spec.

 

[Turdle]

Something is wrong.
I have an x cam and pull 16in at idle

I think you have a vacuum leak somewhere-A big one.

 

[dani9678]

The only problem is I can't seem to find one. I don't hear any hissing other then at the air intake and when I spray the brake-clean around the engine and under the upper plenum, there is no change in rpm. at one point I thought of taking off the oil cap and check for a vacuum leak there just in-case the leak was under the intake manifold and it was sucking air from inside the valley of the engine but I didn't find any. Is there another way to find the vacuum leak?

 

[Turdle]

Wait-!
Did you use longer push rods? Did you shim your pedestals? Check valve lash?
Are you certain the cam was timed -( degreed) in correctly, or did you just swap it in?

 

[Turdle]

Do this--check the compression on a few cylinders-
I wonder if your valves are closing all the way-
If you used longer push rods, and no shims, this could be the trouble-

 

[dani9678]

No, I just swapped it in and made sure that the dimples on both sprockets met each other. I was informed by the owner of the speed shop that we ordered the cam thru that it was a direct swap in replacement. That there was no need to change anything else other then install new roller lifters with the cam. I was informed that any cam above the E303 may require some modifications such as replacing the push rods and rockers. I also replaced the timing chain with another roller because there was some slop in it.

 

[Cobraguy]

Something is wrong.
I have an x cam and pull 16in at idle

Can't compare using you JT. Don't you have a 347? It will tame a camshaft much more than the 302. But 5" is just not enough.

That cam should bolt right in without mods, but you need to follow JT's advice and check compression and valve lash. At tdc, that cylinder should go to zero lash then no more than one turn max.

Oh...that cam will also have less bottom end than the stocker. But a lot more mid and top.

 

[dani9678]

I went to the Ford Racing website and looked up the cam and found the following note that was attached to the part number.

(1) On EFI engines, performance camshafts work only with mass air induction systems. Will not work with Explorer EEC-V EFI.

The explorer has an EEC-V computer. Can this cause a problem? I know that it doesn't have anything to do with the vacuum situation but I'm not sure what other problems this will cause.

As far as the valve lash. I made sure that the valves were fully closed by watching the gap in the amount of time before the valves would open again and then I would back it off to the halfway point and then I would tighten the rocker arms.

 

[BronkStang]

uhh theres a few guys on here running e303 cams, just do a search.

theres something funny going on. id start with the easiest things like the firing order, checking tdc, timing (i believe theres an adjustable crank trigger in place of a regular dizzy) and you can pinpoint vacuum leaks with wd40, or even propane (at your own risk: i read it in car craft and tried it, it works) hopefully your not a tooth off...

 

[Cobraguy]

I need to look and see how and why the catalog references that language. But the way I understand it, the E303 cam is emissions legal in a Fox bodied Mustang. It is not emissions legal in an Explorer with an automatic transmission. So you won't have a valid CARB number. That doesn't mean it won't work however. But I would think a looser converter would sure help with that cam.

I'll bet JT's 347 would really work well with that cam with an a/t. Those extra cubes would make that a very well mannered came shaft.

 

[Turdle]

410 fortune runs an e cam in his explorer, untuned, in Colorado.

hmmm, Section525 has an e-cam I believe, in california. Also untuned from what I recall.
Both are automatics

Look elsewhere for your issue-

 

[CDW6212R]

Ditto, I agree to look for vacuum related items. The lifter preload should always be checked when installing a cam. Jon is right about checking that with a compression test.

The stock valvetrain is not adjustable. The rockers bolt down with the cam in any position, but when changing parts the lifter preload should be checked. The compression test can point to valves being open too long etc. Checking them is as Cobra described, with the cam on base circle(as you did), see how far the lifters get crushed. Regards,

 

[jah81592]

Everyone is digging deep but what firing order did you use on this cam? I have heard of this same situation with a customer using a 302 based firing order with a 351. The particular cam you have will have a 302ho or 351 firing order. Believe me it won't back fire but will be weak as hell.

 

[Cobraguy]

James, it should be the same firing order...13726548. The Explorer and the E303 both have that firing order. That's not to say you're dead on the money and the OP has them installed wrong. Worth a check for sure.

 

[Cobraguy]

By the way, you can make the valve train adjustable by utilizing shims under the pedestals. These can usually be ordered from most performance cam companies and places like Summit. But honestly...I've installed a few E303's and never had an issue with lifter preload.

 

[dani9678]

I thought that I'd mention that when I was reinstalling the throttle body elbow to the upper plenum, we had to get another gasket from autozone. When I tried to put it on I noticed that the opening was slightly smaller so I decided to cut the center piece out and just leave the outer puremeter intact so that the outer part would seal. Just before I installed it I noticed that there was a smaller hole below the main opening of the intake plenum. Do you know what this smaller oval hole is for? I noticed that the gasket had a smaller opening in it just below the main opening but when I cut the center out, I eliminated that seperate hole. Basicely the gasket looked like a square before I installed it. I wonder if it could be sucking air oround that smaller hole into the main intake. I figured at the time that it was just a cavity.

 

[CDW6212R]

Yes that is the EGR passage, but you should have an external EGR. You should have left the gaskets alone.

 

[dani9678]

My Nephew had disassembled the intake to have it cleaned. So I we had to get new gaskets. Will this cause a problem?

 

[Turdle]

I think the egr is plugged at the elbow anyway-I might be wrong but this shouldn't be a concern.

James might be on the right track-

I have another thing to check-
set the engine to #1 TDC ( compression stoke) and tell me which direction the cam sensor flag is pointing. The flag is a half circle under the sensor cap-
is it pointed like this -- ( -- or like this--- ) ---when looking from front of engine?

 

[CDW6212R]

Yes the external intakes have no EGR passages in them, the earlier intakes did. I'm sorry if I sounded like I suggested that it is your problem. Go through the basic checks and see that everything is how it should be.