Hello all.
I have been coming here the last several years, able to find the answer to all my questions and I've been through several MB replace/repair jobs where all of your input has come in REALLY handy. However, I now find myself in a bit of a pickle.

I just replaced the intake manifold on my 2007 ML350. I was slightly rushed when doing the job and I'm afraid I may have missed something. BUT tracking it down is another issue. After job completion it would not crank. I found a unattached vacuum hose (MAF), loose connection (Bank 1 "psngr side" CPS), and not to mention a completely loose wire. going to something else that I can't remmeber at the moment. This was several days ago. I got all that connected up properly and it does start. Yet it heaves and almost dies then revs again and alomst dies, and check engine light began flashing. To make a long story short... Since then I was able to go back and re-check all vacuum lines (i think) and all connections have been cleaned with electrical spay and dried and re-attached frimaly with locks in place. It still does this heaving/revving up then almost dying thing over and over and I am ending up with the following codes....
P0300
P0304
P0305
P0306
Has anybody had this experience before who may have a good idea what I missed? It was running normally before the Manifold change out. It just would not pass inspection with the check engine light on. We cleaned the 2nd Air Injection Sysytem out which used to fix the issue but not this time. It was a busted intake. My next step is to get home tonight and take the entire job apart and begin the re-install over from scratch. Unless somebody has a good direction to point me in first. (feel free to reply late too, because I'll be up wokring on it) Oh I may have left the hose going to the back/bottom of the throttlebody detached. Would that cause THAT much of an issue?

Any help would be appreciated, as always.


Thanks all,

Boedie
2007 ML350
2010 E350
2012 C300

 

Well, I did find an issue with my install. But it is still giving me problems. I found I had folded the gasket in on itself at cylinder 6. Straitened it put and made it where it would stay attached to the intake while re-installing. After 2nd attempt, I am still getting p0300, p0306, p0305, and p0304. I replaced the coil packs, spark plugs, and the MAF sensor. Now getting p0300, p0306, and p0302. I'm about to take the whole thing apart agaIn,, to check my work. If anybody has ever had this issue, or if you have a good idea as to what's causing this misfire, please respond.
Should I spend the cash and get a better analyzer that will tell me more information, or would that do any good? I just feel like there is more the computer could be telling me. And I don't have the equipment to display that. What do you think?

 

If you do your own work, you'll never regret owning a good scanner. I'm a fan of always getting the best tool you can afford and to that end I dropped about $1K on a Launch X431 V+ a few years ago. It came with 2 years of free upgrades that I have since let lapse because the cost to continue is about $500/year. Hasn't let me down yet, has saved literally thousands (multiple) in auto shop bills on multiple vehicles, and Amazon even rewarded my hesitance at buying it with a hundred or so off after leaving it in my cart for a night.
Yes there are cheaper ones out there that are brand specific (looking at you Icarsoft MBII) but this one is light years ahead in accuracy, reliability, ease of use, and flexibility.
Can't speak to other brands as these are the only ones I've used, but the point is to answer your question: Get a good scanner.
Edited to add: Sounds like you've got a severe air leak on the intake. The folded gasket isn't doing you any favors; replace it.