Procharger install problems on 7.4 MPI 310HP
 

I decided it was time to boost the speed of my 2000 Mariah Z302 which came with a single 7.4 MPI (310 HP) paired up with a Bravo III. I chose to do that by adding a Procharger SC unit with 5 PSI boost. After getting the thing installed, and pushing my props from 28 to 30 pitch, I took it out for the first test run. Once I got it on the water, I could tell right away that there was much more power and I came out of the hole faster even though I had larger props. All was well until I hit 4500 RPM at which time the engine started to stall and the exhaust gas got very hot. I could not imagine hitting the rev limiter at that low RPM, but after looking at the factory info on the top of my engine, I saw that the factory setting was for 4200 too 4600 RPM. It was then recommended for me to get my ECU re-programmed to solve this issue. The factor ECU was a FE28. I sent it off to have it re-programmed (several times, but that is a different story) and now things are worse. The Engine is cold starting (but something I can live with), but I cannot open the throttle all the way open without the engine starting to studder and then I get an engine alarm beeping at me. This happens both right out of the hole or if I just ease up the RPM until I hit around 4400 RPM. I am also noticing that the engine is now running very rich as everything is getting black. After two weekends of running like this, I had to change the oil due to dropped pressure and my noticing that I smelled gas in the oil. Has anybody else experienced anything like this or can offer any help? Thanks, Dave

Re: Procharger install problems on 7.4 MPI 310HP
 

First thing you should not have done is Procharge a 7.4 MPI. It has cast pistons that cannot handle the heat and any long term reliability is unlikely.

I think the rest of your issues revolve around ecu programming.

Re: Procharger install problems on 7.4 MPI 310HP
 

Hi

I thought many people have procharged their cast piston 7.4mpi's without issues in the past?

regards,

Richard

Re: Procharger install problems on 7.4 MPI 310HP
 

Where are you located?

Re: Procharger install problems on 7.4 MPI 310HP
 

You need a efi expert to tune your boat on the water,pure and simple. Depending where your at find someone willing to do it,install a bung in your manifold for a 02 sensor. In mich we use Tyler Crockett,he tuned my procharged boat on the water and it runs excellent,Smitty

Re: Procharger install problems on 7.4 MPI 310HP
 

I am located close to St. Louis MO.

Re: Procharger install problems on 7.4 MPI 310HP
 

You will get gas in your oil, it's caused by the blower and blow by. You'll need to change your oil often, like 15 - 20 hours. How amny hours were on the engine before installing the blower?

You really should be cautious with the 7.4 the pistons and crank are cast, not forged.

The previous owner of one of my boats ran a 7.4 for 3 years with a Procharger with no problems.

Kirk

Re: Procharger install problems on 7.4 MPI 310HP
 

Who is setting up your ecu? sounds like your too fat at idle and leaning out up top. tuning is critical, my boat couldnt idle 5 minutes without fouling the plugs, got the ecu set up right and its been great since. Dont give up it will work out.

Re: Procharger install problems on 7.4 MPI 310HP
 

Send your ECU to Arizona Speed and Marine they will take care of all of your issues and they have some great people down there to work with. Call down there and talk to a guy named Jim, ask him your questions and he will give you some straight answers.

Re: Procharger install problems on 7.4 MPI 310HP
 

It sounds as if you fuel pressure regulator gain is not set up properly. The fuel pressure may be but the gain rate to full psi may need tweaking. Procharger sells the regulator adjustment kits. I also have or can get you them as I am a distributor.. Also despite what others may say @ 5psi you should not have had to reflash the ecm on an otherwise stock unit for it to run properly.. I too have seen a bunch of hrs on procharged stock engines.. The key is not to be abusive and make sure you pamper it with services early ..

:) Jamie / Lakeside

Re: Procharger install problems on 7.4 MPI 310HP
 

I respectfully disagree - 5 psi without ecm recal = BANG! Have you talked to Zeke at Gruninger's?

Re: Procharger install problems on 7.4 MPI 310HP
 

No problem you are entitled to your own opinion.. I have installed numerous prochagers as a distributor.. Havent had any pop becasue of not recaling the ecm when set up properly. Not all of them need recals if set up properly. I never said that there werent exceptions to the rule. Dont just take my word for it, call ATI if you dont believe me, ask for one of the engineers like Dorian or Jim... Just out of curiosity are you an installer, or a boat owner with a SC?? I am not bashing you, I am just stating our experiences & Ati's installation & set up instructions and reccomendations.. Jamie / Lakeside

Re: Procharger install problems on 7.4 MPI 310HP
 

No issue with procharger - just disagree with the install without ecm change.

Do I own a boat, not at the moment we are headed to the other side "cruiser" Last of the kids are gone and looking for a floating cottage.

Do you guarantee your customer's engines won't grenade without an ecm upgrade when you install a kit? If not, why not if you are so sure?

What parameters do you use to determine if an ecm needs reprogrammed before the engine is damaged?

I know that not all engines are created equal, but I would guess that the base 7.4 doesn't vary too much engine to engine. Why would one stock 7.4 require an ecm change and the next one not when the calibration is the same in all of them?

Not bashing either, just curious.

Re: Procharger install problems on 7.4 MPI 310HP
 

My personal experiences with Procharger installs on stock engines is that the ECU does not require recalibrating, only that the fuel pressure is raised.

The problem does definately sound fuel related. I would suggest the ECU be sent to Mark at Percision EFI or Tyler Crocket to be recalibrated back to stock or what ever they would suggest. I have not had great luck with AZ Speed.

Re: Procharger install problems on 7.4 MPI 310HP
 

I already specified why above as is did annother individual above. Whipple does recal or replace ecms depending on application, ATI does not.

If this is not your thing & not your field there is little reason to doubt me.

I install them properly & as per the ATI's or Whipple's etc.. instructions. As far as guaranteeing that an engine will not launch at a later time due to a SC upgrade I dont know of anyone who would gurantee that an engine will not ever launch. If they do they are charging you extra for an insurance policy on it to redo it in some form or annother. For example there is a huge diffenece in price on installing an add on Procharger VS buying a warrantied blower motor from merc with a 90 day warranty. Nothings free, you alway pay for what you want in one form or annother. Some warranties are jokes & just not worth the money..


If it is stock I leave the ecm alone unless after PROPERLY setting up the fuel & spark system it doesnt run or operate properly.. this is a rare exception. The only time I would recommend a recal is if you are running more than 5 psi boost and or you have done other major internal & exhaust mods. As this could throw off the ecms parameters it needs to see more than running 5 psi boost or less with a procharger.

I addressed this in the above statement. Also As I said earlier Whipple & some others do require it due to thier fuel delivery systems etc... But again ATI's doesnt require it, it is only with some fairly rare exceptions that it ever needs to be done on a stock engine with a low boost procharger upgrade.. Also Ati has ECT sensor conditioners for certian applications if needed, as well as fuel psi reg gain realibration kits. Recaling a stock ecm on a low boost set up that wasnt installed with fuel & spark st up properly may actually mask a potential problem like the person who started the thread is experiencing. Once it is set up properly if you want to recal an ecm to further tweak a system is an entirely different scenario and may or may not be worth while depending on why one is thinking of doing it..

Neither am I, but I am an experienced installer and I am just stating what normal ATI procedure is. Where as you on the other hand are evidentally not an installer or operator of this sytem. Again I am not bashing you I am just stating the info & experience at hand.. Again if anyone doubts me feel free to ask ATI.. :)

Jamie / Lakeside :)