Morning 4.9ers! Been doing a bit of research over the last couple days. I have come to the conclusion that there are some great injectors out there that can be used on a 4.9. I'm basically looking for drop in replacements. One "could" technically modify the fuel rail to use practically any injector but for the purpose of this discussion lets try to stick with drop ins. Since I didn't know much about injector types and styles I needed to do more research.
It been said over the years that 5.0 mustang and camaro injectors work good in a 4.9. I decided to take a further look into this and see just what exactly was out there.
My search started with the stock 4.9 injectors (model # FJ101, if you were wondering). I wanted to know the specs so I could find a close match. Reading into them gave me the info I was looking for. They are a Rochester made high impedance Multec injector and flow ~19lbs/hr @ 43.5psi. A 4.9 uses slightly less pressure then this, usually around 40-42psi. They are a ball and socket type injector which provide excellant fuel atomization and a wide spray pattern. These are fantastic attributes in an injector and is really their only advantage. They have many disadvantages also. The main one being the ease at which they clog and/or electrically stop functioning. The second is price, which is rediculious if you want a new identical replacement. Being that the only NOS set I've ever seen cost in the range of $800+ for the full set of 8. This was absolutely out of the question for me. This is about what I spent buying, rebuilding, and camming my 4.9.
After looking into the stock injectors I started doing some checking into other types of injectors. I decided to call a professional first to get the low down from a good source. I called a local place called Dr Injector to get price quotes on cleaning and flow testing/matching the ones I have. That price came to $25 per injector but he matches your set to within 1ml of eachother (industry standard is 2-3ml). Not a bad price considering. With a bit more discussion I was told that there are quite a few suitable replacements for a 4.9. One of the ones he recommended was a disc type bosh injector. He said they have fantastic reliabilty and service life, good atomization, match the mechanical size exactly, and are nearly perfect from a flow standpoint.
I took this info and started looking more into some different brands and styles. This led me to 2 in particular that fit exactly what I'm looking for in an injector.
The bosch design 2 (19lb yellow top, metal bottom, disc type, 4 hole, high impedance, with EV1 plug to be specific. ): These are great injectors. Stock for many ford cars and trucks. Mustang, crown vic, F150, F250, ect. They are also used as replacements in many GM, BMW, and other brands. They have the fantastic service life, reliability, and good fuel atomization. They are also less prone to failure then the Multecs are. They are easy to find new, matched remanufactured, or even just used pull outs. Prices are much better then stock multecs.
Since I know these fit the 4.9 I decided to check out the mustang, cadillac, and other forums to see what they are using. Most people still use these with great results. But there were quite a few mentions of a newer Bosch design 3 being used as a drop in upgrades for the 2. So I went on the hunt for info on them...
Bosch Design 3 (19lb yellow, all plastic, disc type, 4 hole design, high impedance, with EV1 plug): These are an even better injector then the 2. They are indeed a direct replacement. They have distinct advantages over the 2 though. They provide even better fuel atomization which helps low RPM response, are more precise in the higher RPM range (because of the lower overall mass), and have an all plastic design which reduces heat soak. Good deal. Started looking into prices. WOW! Apparently, they are even cheaper then their gen 2 couterparts also.
Found a few videos of the results.
You can see for yourself how much better the spray pattern and atomization is. I was suprised to say the least.
The second video here is a comparison of the Bosch 3, Lucas disc type, and GM multecs. Very interesting!
This video suprised me also. Even more so when I watched it a second time and realized the lucas were brand new, never run, the multecs had been cleaned and flow tested, and the Bosch3's were not even cleaned! The bosch 3 even sppear to beat out the multecs for spray pattern and atomization.
So I decided to find and order up a set of Bosch gen 3 and see how they work. Found a reman set of 8 for $79.99 shipped. Yes, you read that right. I also saw several sets of used pull outs in the $55-60 range for a set of 8. When they get here on on saturday I will put them in a get a good before and after video of the difference. I will also do a direct comparison between these and the stock 4.9 multecs I have in the car.
Another bit of info. http://www.mrinjector.us/problem-injectors.html Specifically states that the 91-95 cadillac 4.9 injectors are problematic. They short out and cause misfires. Also states he replaces wtih bosch design 2 injectors. I absolutely believe it.
If you guys have experiance with other injectors post your results here. I'd love to find and look into even more options. And don't forget to stay tuned for my results of the bosch 3.
EDIT: Almost forgot. These may also be a good replacement... http://www.summitracing.com/parts/VNM-HP-619-8/ Venom High flow 19# injectors. Flow matched to withing 1% from the factory. Great price point at $216 for a new set. Someone would have to check them out to be positive but they look very promising.
Also found MSD, Edelbrock, Accel, and many other brands that offer a 19lb injector. The accels deffinately work. Not sure on fitment on the rest yet though.
[This message has been edited by Fieroseverywhere (edited 05-24-2010).]
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11:32 AM
PFF
System Bot
Isolde Member
Posts: 2504 From: North Logan, Utah, USA Registered: May 2008
A wide spray pattern isn't a good thing in the LS series, too much port wall wetting. They revised the injectors to reduce this. You want the fuel in the airstream, not dripping.
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01:49 PM
blackrams Member
Posts: 31841 From: Hattiesburg, MS, USA Registered: Feb 2003
When I needed new injectors for one of my 4.9 cars, I got some rebuilt ones from a company in Atlanta. They offered them two ways, matched or unmatched (as in not specifically mated with other identical spray injectors but still good). I chose the unmatched due to price but, it was less than $300 for the entire set and they run just fine. Nope, I don't consider this particular car a race car, it's simply a Daily Driver. Can't remember the name of the company but if is shouldn't be hard to find.
Ron
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01:50 PM
Fieroseverywhere Member
Posts: 4242 From: Gresham, Oregon USA Registered: Mar 2006
This reminded me that as a comparison I should also hook up the scanner to get the BLM, Fuel intergrator, and O2 cross counts with both injectors installed. At the moment my BLM's and intergrator are all over the place. Because of this the O2 also jumps from extremly rich to extremely lean on a regular basis. SInce its all so inconsistant the PCM can't switch fast enough from adding to removing fuel. At this point I know this has to be an injector problem as everything else is new or rebuilt.
For those who don't know.
BLM = Block learn mode. This is a number that the PCM decides on for how much fuel the individual banks of the block need. It is suppose to determine this based on O2 data and some calculations.
Intergrator = Actual number the PCM uses to indicate the how much fuel is being added or subtracted. Ideally there would be none but that apparently rarely happens. You can also look at the injector pulse width to see how long the injectors are open.
O2 reading = How much oxygen is present in the exhaust. Shows how complete the burn is and whether the amount of fuel added is correct or not.
These readings should give me a good indication of how the new injectors perform compared to the old ones.
EDIT: One more interesting thread on the 4.9 from the caddy forum. This one covers many performance mods for the 4.9. One of the more interesting to me is the adjustable fuel pressure regulator. http://www.cadillacforums.c...ons-4-x-engines.html
[This message has been edited by Fieroseverywhere (edited 04-22-2010).]
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02:27 PM
katatak Member
Posts: 7136 From: Omaha, NE USA Registered: Apr 2008
I recently went through the "learning" process related to the 4.9 injectors. I sent the factory injectors to Mr. Injector for service and cleaning - the box arrived there with no injectors - still fighting with UPS over that - but during that fiasco, Bill at Mr. Injector told me that he does not recommend using the factory Caddy injectors as they tend to short out internally. As stated above, he recommened replacing them with the Bosch type 2 or type 3. I ended up with type 2 and I have not run the 4.9 much since installing it in the car but in comparison to another 4.9 here in El Paso, the throttle response seems a lot more crisp and responsive with the Bosch type 2 injector? I pulled these from a 94 Crown Vic with a 4.6 - ex police cruiser and sent them to Mr. Injector for service and cleaning. So far so good.
Pat
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06:47 PM
Raydar Member
Posts: 40725 From: Carrollton GA. Out in the... country. Registered: Oct 1999
When I needed new injectors for one of my 4.9 cars, I got some rebuilt ones from a company in Atlanta. .... Can't remember the name of the company but if is shouldn't be hard to find.
Funny. Thats the place that the videos I posted are from.
I found several sets of the reconditioned type 3 Bosch on ebay for right around 80 shipped. They're not flow matched or anything but are cleaned and tested working. I'm hoping to see a vast improvement over my craptacular (yes, its a word ) multecs.
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10:07 PM
Apr 23rd, 2010
Raydar Member
Posts: 40725 From: Carrollton GA. Out in the... country. Registered: Oct 1999
Those are the wrong ones. Well, right style but with the wrong connector.
There are quite a few guys running the 3's on the caddy forum. Seem to work out well and come highly recommended from what I've read. I'll post some pics of a direct comparison when mine show up. Probably monday.
Katatak here has the 2's (and some other forum members also). They seem to work great based on his video. Actually his 4.9 is much smoother then mine has ever been. Thats what got me started on the search. Thanks katatak!!
[This message has been edited by Fieroseverywhere (edited 04-24-2010).]
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09:27 PM
PFF
System Bot
Apr 25th, 2010
katatak Member
Posts: 7136 From: Omaha, NE USA Registered: Apr 2008
Those are the wrong ones. Well, right style but with the wrong connector.
There are quite a few guys running the 3's on the caddy forum. Seem to work out well and come highly recommended from what I've read. I'll post some pics of a direct comparison when mine show up. Probably monday.
Katatak here has the 2's (and some other forum members also). They seem to work great based on his video. Actually his 4.9 is much smoother then mine has ever been. Thats what got me started on the search. Thanks katatak!!
As much as I'd like to take credit, I stumbled on them by accident. If UPS had not lost my original injectors, I'd be running them right now. I have read a little more and I thik you will like the 3's even more - I may be looking for a set of 3's after you get your results..
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12:02 AM
Apr 26th, 2010
Fieroseverywhere Member
Posts: 4242 From: Gresham, Oregon USA Registered: Mar 2006
Injectors arrived today. They look good with one exception. They did not install the filters. I contacted the seller and he was very apologetic. He offered to send me a set of filters but I declined and have decided to pick them up locally from a injector rebuilder (Dr. Injector) . That way I can still install them tonight. Cost is only 2 dollars total for all 8 filters.
I may have them flow checked while I'm there also. I was told the cost for that is 4 dollars per injector. Might just chock that up to cheap insurance. Haven't decided yet. Opinions?
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05:33 PM
thumper_64735 Member
Posts: 704 From: Lebanon, MO, USA Registered: Sep 2006
Very interesting discussion. I will be waiting to hear what the outcome is of the performance of the engine with the upgraded injectors. Thanks for doing this study, and a + to you.
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08:21 PM
Fieroseverywhere Member
Posts: 4242 From: Gresham, Oregon USA Registered: Mar 2006
Ok. In and working with only a couple scares. My own fault of course.
So here they are... OEM Ford Bosch 3 injectors.
Forgotten filters installed. Total cost 5 dollars. I gave him a couple extra bucks to put them in for me. He is a pro afterall.
4 holes...
Feel like I'm going to break these things just holding them... Significantly less mass overall then the original 4.9 injectors. This is suppose to make them more responsive. Since its measured in miliseconds there is no way to tell for sure.
Correct connector... Snapped right in.
Fuel rail out of the car... Pretty dirty! Amazing considering only 4300 miles on everything.
Old and new injectors side by side. Fuel rail clips also...
Man those are dirty... Really dirty.
Overall height, nearly identical...
Slight difference in lower o-ring height. Still went in without a problem. No vac or fuel leaks.
Prognosis. Great upgrade. Smoothed out the idle immediately. Much more responsive throttle. Got rid of some of my PCM fuel control issues. This probably would have happened with any injector change though. Too soon to tell on gas mileage or power output (not expecting much here) but I'll update when I have that info. It may not be the best comparison considering the condition of my old 4.9 injectors. I'm happy with them though. Total time for change out ~45min. Completely bolt in. No mods needed.
The couple scares I mentioned eariler....
1 - forgot to plug the injector harness back in. Couldn't figure out why it didn't want to start. 2 - The plug for the ISC had come undone. Idle wouldn't drop below 1300. Both were easily corrected but gave me a scare at first. I should pay more attention!!
I still have to get the car out a run it though its paces. That won't be today unfortunately. I have no hood and its pouring down rain. Hopefully have the hood vent finished in the next couple days and get out for the true test. Now that its idling right again I will redo the idle learn procedure and see if I can't clean it up a bit more.
[This message has been edited by Fieroseverywhere (edited 04-26-2010).]
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10:08 PM
josef644 Member
Posts: 6939 From: Dickinson, Texas USA Registered: Nov 2006
Good luck with your injectors. Mine are similar, except that they came with two O-rings on the bottom. I left them both in place. Figured it would help to keep crud out of the hole.
Do keep us posted.
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10:54 PM
Apr 27th, 2010
katatak Member
Posts: 7136 From: Omaha, NE USA Registered: Apr 2008
I'm guessing that you did not use the retaining clips? I do not see a "groove" for the clip to secure it to the fuel rail. Does it simply hold the injectors in place via the fule rail bolts? Can't wait to hear what she runs like. Looks good so far.
Pat
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12:02 AM
Fieroseverywhere Member
Posts: 4242 From: Gresham, Oregon USA Registered: Mar 2006
You were gonna post the video of the idle setting etc.
I still will. Now that my idle issue are fixed I can do it properly. I just couldn't get a steady enough idle before. Sorry its taken so long.
quote
Originally posted by katatak:
I'm guessing that you did not use the retaining clips? I do not see a "groove" for the clip to secure it to the fuel rail. Does it simply hold the injectors in place via the fule rail bolts? Can't wait to hear what she runs like. Looks good so far.
Pat
I used them. Right where the injectors plug into the rail there is a bulge. The clips go around that. Honestly though there is no way those injectors are coming out with the fuel rail bolted down. The clips are just to keep the injectors connected to the rail when you remove it. I'll get a video soon. Got busy tonight and am just now getting home. Long day.
quote
Originally posted by Raydar:
Good luck with your injectors. Mine are similar, except that they came with two O-rings on the bottom. I left them both in place. Figured it would help to keep crud out of the hole.
Do keep us posted.
These didn't come with a second o-ring at the bottom. Wish I would have thought of it. I would have robbed some off the caddy injectors. There is no way I'm pulling it back off now. You guys will have more info as soon as I do.
[This message has been edited by Fieroseverywhere (edited 04-27-2010).]
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12:37 AM
May 5th, 2010
thumper_64735 Member
Posts: 704 From: Lebanon, MO, USA Registered: Sep 2006
My registration was up at the end of april. In order to get new tags I had to pass emmisions. However the car had other ideas. Odd considering its currently running its best ever. I had it tested twice last week. Wednesday failed with HC=483 (220 allowed), CO 1.17 (1 allowed). I'm still quite suprised it didn't pass the first time out. Took it home, adjusted the timing (was a bit low), swapped out O2 sensors, changed chips to the one I was using last time it passed, a little Seafoam in the gas tank, ect. Took it back on thursday and it failed again. This time HC=760, CO=1.3. Both times looks to be a rich misfire condition. At least that explains the high HC and CO at the same time. Been testing and working on emmisions stuff ever since (replaced carbon covered plugs, fixed broken plug wire, ect). I picked up a trip permit yesterday because I believe I have the issue resolved at this point. That why the delay.
Since the roads dried out a bit yesterday evening I took the car out for a hard drive. Easily the hardest I've ever pushed it at this point. I want to get the tank cleared of the seafoam so I can retest. Took the fiance with me too. I good hard drive always gets her going, especially the way her seat vibrates. Out there the speed limits go away, there is almost no traffic, the corners are great, and the roads are decent. 20-30 mph recommended speed "S" curves, 10-15 MPH switchbacks, several 10-15mph 90 degree corners, and enough straights to reach 90-100 mph in places (at least with the 4.9). Lots of trees and beautiful scenery also. The car took everything in stride and worked beautifully. It was by far most trouble free drive I have ever had in this car. Also the first time that ALL drivetrain issue are fully resolved (finally! ). It was time to stop when the brakes started to fade. At least I now their limits now. I was suprised how long they lasted actualy. The only hiccup on this trip was on the way back.
While stopped at a stop sign the idle shot up to 4k rpm and held for a few seconds. It settled back down and hasn't had the same problem since. I'm almost positive it has something to do with the idle learn that still needs done but I'm also concerned the ISC or TPS may be showing a problem. No codes set. I'll have to check it out better tonight.
The injectors have worked perfectly in every situation so far. Have put about 300 miles on them. Mileage seems to be up a bit. Absolutely no complaints. Would use them again anytime. I'll try to get out for another trip in the next few days, this time with a camera rolling. You guys will probably get a kick out of it. It is the exact purpose I built this car for. The best therapy ever!!! Slept like a baby last night for the first time in quite a while!! I really needed that!
[This message has been edited by Fieroseverywhere (edited 05-05-2010).]
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10:14 AM
May 22nd, 2010
Fieroseverywhere Member
Posts: 4242 From: Gresham, Oregon USA Registered: Mar 2006
Its possible that they are complicating my emisions problems. At this point though I seriously doubt they are causing it. My emissions problems seem to be a few minor problems stacked up. It may just be the particular injectors leaking though. Thats why i'm not counting them out yet. When you buy used crap you somtimes you just get used crap.
One of the issues I've stumbled upon during this is the resistance of the injectors. Caddy injectors are good between 15.8-16.6ohms according to GM. These bosch injectors normally run at about 14.8-15ohms give or take a bit. Not sure if this is an issue or not but I'm not counting it out. There is no question they work but just working and working correctly are two different things. I'll post more when I have it.
[This message has been edited by Fieroseverywhere (edited 05-23-2010).]
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05:37 PM
Raydar Member
Posts: 40725 From: Carrollton GA. Out in the... country. Registered: Oct 1999
Don't sweat the difference. I ohmed out two sets of injectors last night. The Allante injectors (gray body) were ~16 ohms if I recall. The 4.9 Deville injectors (black body) all ohmed out to 12 and a tenth or two. Otherwise, they appeared identical.
I don't think an ohm or two is going to make a difference. They're all, technically, high impedence injectors. I think that as long as the impedence is high enough that they don't fry the drivers, it won't hurt anything.
I got the (apparently incorrect) idea that your injectors were new. I'm betting that at least one of them is leaking. When you turn the key and the fuel system primes, is it maintaining pressure with the engine not started?
[This message has been edited by Raydar (edited 05-23-2010).]
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10:54 PM
May 24th, 2010
Fieroseverywhere Member
Posts: 4242 From: Gresham, Oregon USA Registered: Mar 2006
They were not new. They were pullouts from a mustang. They were said to be cleaned and flow tested but apparently that was . My 4.9 injectors here ohm out at 16.0-16.3 accross the board.
I didn't think the minor difference in resistance would be a huge deal. But wanted to be sure first. Looking at my plugs this time (after ~300 miles) 3 of them had alot of buildup on them and came out wet. Most likely 3 injectors were leaking with one being very bad. Mix this with the other minor issues I had and you get a deffinate emissions failure.
Leaking injectors, EGR valve stuck open, vac leak when EGR solenoid was open, and bad ground for the coil. Best I can tell the extra carbon from the stuck open EGR mixed with the raw fuel from the leaky injectors and a sludge layer formed inside the intake manifold and combustion chambers. Having a high fuel content the sludge was very high in HC. The coil not puting out enough spark only made the issue worse. Its a complete mess and will take me a good week to clean out the intake. I have terrible luck.
This is what the underside of the throttle body looked like... With this much crap there you can only imagine what the rest of the intake looks like. Its not hard and baked on, its a slimy sticky sludge. No wonders the car started smoking when I fixed the coil ground.
[This message has been edited by Fieroseverywhere (edited 05-24-2010).]
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10:41 AM
SMTHGT Member
Posts: 1075 From: Seagoville , Tx. Registered: Mar 2010
WOW.... That may be some of your idle promlem... How many miles if I may ask..??
5200 since the rebuild. Completely disassembled and hot tanked. It was very clean when installed. Whats even worse is I loked at that throttle body when I installed the new injectors. This was about 800 miles ago and it was much cleaner then.
My 4.9 injectors have a grey body.
quote
Originally posted by Quad GT:
Have you ever thought about carbing the 4.9?
Very briefly. It ends up being more work then just wiring in the PFI.
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03:23 PM
Raydar Member
Posts: 40725 From: Carrollton GA. Out in the... country. Registered: Oct 1999
Holy smokes! With all that sludge, it looks like a 100K Fiero upper plenum.
I think you found your problem.
Ha! I was thinking the same thing. When my first 2.8 went out it had 148k miles on it. It wasn't this bad.
I certainly hope this is my problem. Parts should be here by friday at the latest. I'll get her back together and see how she runs/tests. Seafoam sitting in the intake right now breaking up some of that crap. I even poured some down the injectors holes. This car is going to choke out the whole neighborhood once it gets started again.
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10:13 AM
Raydar Member
Posts: 40725 From: Carrollton GA. Out in the... country. Registered: Oct 1999
He he. No. Not enough to do that. Less then 1/2 can total with the majority down the throttle bores. After a few days soaking I'll fire up the shop vac and suck most of it out. The rest will burn up on first fire up. Its still going to smoke like a chimney though.
[This message has been edited by Fieroseverywhere (edited 05-25-2010).]
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01:42 PM
Jun 9th, 2010
josef644 Member
Posts: 6939 From: Dickinson, Texas USA Registered: Nov 2006
At this point I suspect they did not play a factor at all. At least not more then any other leaky injector would. When I switched back to the caddy injectors there was not a huge difference in emissions. A little better because the caddy ones don't leak but not enough. This lead me back to either ignition or induction problem. Since I'd already been through the entire ignition system I looked into induction. What finally did it was the removal of the cold air intake. I put on a new intake which pulled warmer air from the engine bay and the emissions dropped like the stock market in 2008. (sorry I couldn't resist. ) I'm working on a fix for this now. It will involve the change in MAT tables in the PCM programming. Apparently there is a limit to how cold of air temps the 4.9 is capable of compensating for. The Allante was setup for lower temps from the factory so I suspect those MAT tables will fix the issue. I didn't think it was possible but apparently your intake can be too cold.
Those ones look right to me. As long as they are indeed the ones pictured. Sorry to hear you are still having injector problems Joe. That sucks!
[This message has been edited by Fieroseverywhere (edited 06-10-2010).]
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03:28 PM
josef644 Member
Posts: 6939 From: Dickinson, Texas USA Registered: Nov 2006
):
The bosch 3 even sppear to beat out the multecs for spray pattern and atomization. 
Both times looks to be a rich misfire condition. At least that explains the high HC and CO at the same time. Been testing and working on emmisions stuff ever since (replaced carbon covered plugs, fixed broken plug wire, ect). I picked up a trip permit yesterday because I believe I have the issue resolved at this point. That why the delay.
. My 4.9 injectors here ohm out at 16.0-16.3 accross the board.
) I'm working on a fix for this now. It will involve the change in MAT tables in the PCM programming. Apparently there is a limit to how cold of air temps the 4.9 is capable of compensating for. The Allante was setup for lower temps from the factory so I suspect those MAT tables will fix the issue. I didn't think it was possible but apparently your intake can be too cold. 
