So, from the book other things I need to get my EFI to run correctly the tech guys seem to think I'm not getting enough vacuum. It was suggested that I need a vacuum pump, with that said does it really matter which electric one I get? Suggestions for a brand, model? I'm currently at 7.5-8.5 inches of vac and the tech seems to think I need a little more.

What does a vacuum pump have to do with getting an EFI equipped vehicle to run right? AFAIK vacuum pumps typically are used to help vacuum assisted components operate when the engine has low vacuum... If your EFI uses a MAP sensor the whole intent is to have it read true engine vacuum which should have a close correlation to engine load & combined with the info from TPS, ACT, ECT & HEGO provides data for fuel trim adjustments...

That is as I said AFAIK.. Now I'll shut up & see what has changed making me wrong....

I wish I knew what was right and wrong. The guy comp cam tech said that 8 is minimum for steady driving and made the suggestion for the electric pump. My father in law had one added to his 6 pak car from a bmw and spent like $350, but he swears the car runs and responds a lot better. Seem like there should be a cheaper option after spending money on the system then dumping way too much extra freakin' money getting other stuff done in the car so EFI would run (I.e. new wiring harness, bigger alternator, heavier duty voltage regulator etc etc.)

Why not edit your title to mention EFI Tuning concerns & see if a PM to Mopar Rich might attract him to this thread....

My knowledge of EFI is primarily OE stuff so there may be a way to use a vacuum pump but I don't know how...

Don't know what your EFI problem is but a vacuum pump will not be the solution.

Kevin

I feel like I'm chasing ghosts at this point. I would love to take it to rich a carlisle since I'm going but I don't trust the car enough todrive it there and have no way of towing it. When a tech guy suggests that the extra vacuum will help it's hard not to jump on the idea. Seems like their are a hand full of pumps from 80's cars and 90's diesel trucks under $100. If it works, great, if it doesn't it's the usual waste of money. I don't know enough about vacuum to make a decision on it's usefulness to my application.

Unless the tech you were talking to thought you had a power brake issue, he is an idiot. Your EFI ECM monitors ENGINE vacuum via the MAP sensor and makes decisions based on that. An external source will not help.

What are the cam specs and how much vacuum do you have now? Cams with big overlap and EFI don't like to play nice together but they can be made to.

Kevin

Comp cams has it listed as duration (@50) on the intake 230 and lift 566. ( web page )

I am currently making 7.5-8.5 in at idle, warmed up

Agree as several have posted, the vacuum pump is for accessories only. The ECU nees to see actual manifold vacuum. A pump won't help. The guy who suggested it was in left field.

With 230 ish duration at .050 and a 110 cl I would expect manifold vacuum to be higher with 426+ inches. I don't know the rest of your combo but it sounds like a Hemi as its a hemi cam. How about the EFI? What type is it? For reference, I'm running EFI with a 243@.050 cam with 108 lobe seperation on a 496 and it idles well at 800-900 RPM with around 13" vacuuum.

I'd start with the tuning. As a guess, you will want 16-20 degrees advance at idle and AF in the mid to low 14's to get best idle. If you get those dialed in I bet it runs better and pulls more vacuum.

It's an EZ EFI system. So far this week I found a small vacuum leak, adjusted the timing and am currently waiting for a buddy to show up with a spare ignition box to see if my box is the issue (has less than 200 miles on it so it should be fine). My alternator is making all of 60 amps, my voltage regulator is a later model one (for the upgraded wiring harness) as well as the distributor and ecu. My hemi is iron head, iron block, forged pistons, steel crank, stock bore, roller cam. WASTED too much time and too much unforseen money on this thing so far.

No. Alpha-N used to be used only for race applications on engines that produce very little vacuum. But it was impossible to street tune an Alpha-N system. The EZ is speed density, which is what you want for 90% of the applications. Newer systems like, the XFI and BS3, have no problem running speed density on low vacuum motors; but these systems have rescalable vacuum sensitivity and require a laptop to do it. The EZ system was setup to make things - well - easy, but unfortunately the vacuum sensitivity is not rescalable.

Nevertheless, I have had good success with the EZ as long as the vacuum signal is stable and greater than 9". I disconnect all PCVs and any other possible vacuum drains.

Another thing that really helps is to increase the initial timing. I start at about 20 degrees. Increasing the timing increases vacuum and really smooths things out. Of course the distributor must be recurved to allow for that much initial timing.