Dorman replacement PI intake manifold comments ?

I thought I was the last remaining owner w/o an intake manifold cracking. Well, I just installed a Dorman replacement PI manifold, and have a huge vacuum leak.

The Dorman manifold had "cone" shaped holes for the fuel injectors. The stock manifold has a circular , "machined" surface for the injectors.

The question is : Do I have to tap in the injectors on this Dorman intake ? I had the injectors flow-tested, cleaned and fitted with new o-rings. Checked all the vacuum hoses, EGR, etc. Any help is appreciated.
 
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Did you "lube" the injector O-rings before insertion? Is it possible that you have a defective unit? Consider comparing your unit to another.

I used a Dorman intake on a 97 NPI Cougar and had no issues with it.

FWIIW, many all plastic intakes crack when the coolant level is allowed to get too low. Apparently the plastic cross over can not handle the hotter than normal steam. There are tons of ppl out there still using the all plastic stock intake with no leaks. But let the coolant level get low or the motor get hot and crack goes the plastic.
 
Did you "lube" the injector O-rings before insertion? Is it possible that you have a defective unit? Consider comparing your unit to another.

I used a Dorman intake on a 97 NPI Cougar and had no issues with it.

FWIIW, many all plastic intakes crack when the coolant level is allowed to get too low. Apparently the plastic cross over can not handle the hotter than normal steam. There are tons of ppl out there still using the all plastic stock intake with no leaks. But let the coolant level get low or the motor get hot and crack goes the plastic.

Aha, Mr Burns.. I used the injector service you recommended (InjectorRX in Houston, TX - a very good service BTW)

Yes, I lubed the "o-rings". The difference between the Dorman injector cavities and the stock injector cavities is vast.I wonder how the injectors can possibly seal. It also makes me wonder what other shortcuts were taken by Dorman (they didn't machine and provide inserts for the COP hold down screws, for instance).

Perhaps I should have paid the hundreds of dollars difference for a Ford part ? That is why I asked this question. And thanks for the responses.
 
C'mon - I'm out a few hundred bucks (plus my labor) so , it looks like I'm down due to crappola parts ? Doomed ? Somebody else may have some constructive comments ? Thanks for the reply, though.

honestly man, its a crappy intake. the ports are WAY smaller the the oem pi. my friends 99 had one on it when he bought it and it was the first thing we changed, and it completely changed the power, sound and running characteristics of the car.

just order the oem PI from summit:nice: i had 2 sitting at my house a year ago, id give you one if i still had one!
 
can i ask how the car is behaving? as in what is it doing that makes you think its a vacuum leak?
The car will barely idle - acts like an old-skool muscle car with a huge cam. Doesn't want to idle more than 500 RPM even when cold. Will die w/o throttle input. All vacuum tubes rebuilt/thoroughly checked. IAC checked/cleaned. New plugs (NGK TR55s) Spools up nicely, though, when I romp on the accelerator pedal
 
honestly man, its a crappy intake. the ports are WAY smaller the the oem pi. my friends 99 had one on it when he bought it and it was the first thing we changed, and it completely changed the power, sound and running characteristics of the car.

just order the oem PI from summit:nice: i had 2 sitting at my house a year ago, id give you one if i still had one!
Well, you know, I like Summit's website - pretty good aite. But the two only intakes they had listed for the 4.6L were for the 96-98, and the 99-04 (PI) Maybe disco'd by Ford ?
 
I installed a Dorman NPI intake on my 98 a few months ago because of a cracked intake, and it went on without a hitch. I also had a slight idle problem before the intake swap, but not so bad that it would die on me. Also, when the engine was cold, it would make a humming sound every now and then, but the hum would go away once I pressed on the gas. I read that a worn out IAC valve will cause this, so I swapped a new Ford OEM piece in it, and the idle went back to normal and no more humming sounds.

FWIW, I would have gone with a Ford OEM PI Intake because it's cheaper than the Dorman NPI, but I didn't have the scratch to do the head swap just yet.
 
I installed a Dorman NPI intake on my 98 a few months ago because of a cracked intake, and it went on without a hitch. I also had a slight idle problem before the intake swap, but not so bad that it would die on me. Also, when the engine was cold, it would make a humming sound every now and then The hum would go away once I pressed on the gas. I read that a worn out IAC valve will cause this, so I swapped a new Ford OEM piece in it, and the idle went back to normal and no more humming sounds.

FWIW, I would have gone with a PI Intake because it's cheaper to get than the Dorman NPI, but I didn't have the scratch to do the head swap just yet.

Don't need PI heads to install the PI intake...