Engine tries to explode after M112

[volver]

SO, yeah, M112 supercharger is installed along with 39# injectors. I cranked the engine with no ignition or fuel until the oil pressure was good. Then I connected the ignition and fuel. It fired up, then tried to rev to 3000 rpm. I got scared and shut it down. Tried to start it 3 times after that, it revs high every time and I shut it down.

=

 

[explorerguy89]

=o that doesnt sound good

 

[volver]

The pictures do not show the the finished product.

I have reconnected all vacuums, and electrical connectors, EGR and what not.

I need to make a tube that goes from the EGR elbow to the supercharger. In order to make this tube I have to get to a welder the welder is at my parents house 15 miles away it will not work in my garage. I made a tube out of PVC to temporarily get me to the welder.

so i need this thing to run half way correctly that way i can make the tube and take it to the dyno.

i need some ideas on how to get the explorer into closed loop quickly so it can tune its self half way.

what about getting a vacuum pump to put on the vacuum for the fuel regulator? this would drop the fuel pressure from 100 to 35 psi that might stop the over supply of fuel. And the over reving.

 

[volver]

I have the Bypass on the supercharger zip tied open that way there is no boost.

their may be a vacuum leak between the plates that adapt the M112 to the 5.0..... but i doubt that. they are on there pretty tight and they have gasket between them. the PVC intake could be leaking also. if there is a leak it is in that part.

normally if i pull off a vacuum the engine just runs like crap.

it must just have to much fuel.

 

[Justawajz]

I have the Bypass on the supercharger zip tied open that way there is no boost.

their may be a vacuum leak between the plates that adapt the M112 to the 5.0..... but i doubt that. they are on there pretty tight and they have gasket between them. the PVC intake could be leaking also. if there is a leak it is in that part.

normally if i pull off a vacuum the engine just runs like crap.

it must just have to much fuel.

Is you maf setup for the larger injectors...?

 

[volver]

nope

 

[Justawajz]

nope

Well you may just just need to get it re-calibrated for them, also I would imagine you would need a tune to get it running right and adjust your a/f ratio and what not....

 

[volver]

I understand that a tune is going to be required. I am looking for a way to tune it without taking the truck to the dyno. Maybe get the dyno to come to me. lol


I cant pay the 100+ dollars its going to cost to haul the truck to the nearest dyno.


I know the ECM will tune the engine to run correctly. That way I could drive somewhere and get a tune. I just need to stop the over revving at start up, get the truck warmed up and in closed loop.

any ideas?

 

[LilRoush]

You need your MAF to match your injectors. That is where I'd look first.
After that, sounds like a vac leak somewhere.

You're probably also seeing some belt slip - if what is in the pic is your current belt wrap.

 

[slammed98z]

The truck must have a vaccume leak for it to be reving to 3000 rpm. Grab a spray bottle with some water and a dab or two of soap and start it up and spray everything intake related until you find a leak. could be a IAC problem also.

 

[2000StreetRod]

Stock MAF sensor?

Are you still using the stock MAF sensor? If so, it should be accurate to 500 cfm. The problem is not with the MAF sensor reading the airflow correctly.

The problem is probably a combination of an intake leak and larger flow fuel injectors. If you didn't have a leak then the mixture would probably be so rich with the high flow injectors that the engine wouldn't run.

Do you have the return fuel system or the returnless? If its the returnless then your fuel pressure regulator is in the fuel tank and playing with the vacuum will have very little (if any) affect. If you have the return system, then maximum fuel pressure occurs at no vacuum. Your vacuum should be high at idle which means lower fuel pressure. I doubt that you can pull and hold a higher than idle vacuum long enough to drive to the dyno.

The PCM enriches the mixture based on engine coolant temperature (ECT). For a cold start my A/F is about 12:1. It then increases as the engine warms achieving 14.7 when the PCM switches from open to closed loop. Even in closed loop the short and long term fuel trim will not be able to compensate for the high flow injectors. Their limits will be exceeded. You can reduce the cold start enrichment by making the PCM think the engine is already warm. Disconnect the ECT electrical connector and insert a 1K or 2K ohm resistor from the connector to ground. That will make the PCM think the engine temperature is more than 200 degrees F. However, as the engine actually warms up the mixture will become excessively rich.

Find the intake leak first. I doubt even a very rich mixture will result in the engine turning more than 3000 rpm unless there is air getting to it.

 

[gijoecam]

Wait a second... If you started the motor as it sat there in the pictures, I can see the problem at a glance: There's no intake connected to the supercharger. Doesn't that mean the engine is essentially running at WOT? That can't be good...

Assuming you have an intake connected to it, I'm leaning towards an un-metered airflow. It's not too much fuel as that will cause it to bog, not rev. What are you using for an intake/throttle body?

 

[LilRoush]

TPS might be another thing to look at if you are using the Lightning TB and related sensors. When I did the M112 set up on my V6, I had to switch the TPS so the car was getting the right reading from it.

 

[BobWiersema]

Nice looking blower

I hope you get the bugs worked out quickly. I know you didn't start it without a throttle body, that picture must have been taken before you finished.

Also, I don't know much about a major mod like that but don't you need some kind of performance chip for forced induction and the larger injectors?

I saw this one at Blueovalchips but there are probably more cost effective ones out there.

http://www.blueovalchips.com/index.php?l=product_detail&p=2

Good luck, post more pictures of the finished job when you get a chance. Video would be cool too.

 

[LilRoush]

The more I'm thinking about this, the more I'd be interested in seeing your vac line set up. I know it was the big bug I faced when M112ing my project a few years back.

 

[Dan Whitaker]

What is your intake made from?

It sure looks like MDF.

 

[LilRoush]

Looks like 1/4" 6061 or 5052 if I had to guess.

 

[cybergasm]

What is your intake made from?

It sure looks like MDF.

X2 i believe that wood under yonder

 

[shadowless127]

You are my hero. I want to supercharge the mounty so bad.

 

[volver]

I took off the GT-40 intake, drew the hole pattern on AutoCAD, drew the hole pattern of the supercharger, designed a way for the adapter to rise above the fuel regulator but stay below the edge of the fire wall.

I nested the 8 lower plates and the 4 upper plates, and took the drawing to the laser cutter in town. Had them cut the plates out of half inch steel. I wanted to water jet cut them out of aluminum to save weight but the cost was going to be more than double.

I turned the EGR elbow 90 degrees so it points up. I used brass pipe from Lowes and adapted the EGR tube. Relocated EGR solenoid and sensor. the TB is in the stock location it still connects to the coil which is in the stock location.

The fuel injectors came from a 2002 Mustang Cobra. The connectors were different so I cut some connectors off of a Dodge ram in the junk yard.

This thing is becoming a Frankenstein beast. Its got a lot of random parts form different cars. There is a lot of Lowes merchandise and what not strung about.