Possibly head gasket blown?
Okay so I was finishing up my sc install and doing the final touches before getting in tuned in a week or so. Anyway a couple weeks ago after installing the sc and 440 injectors I drove the car around a little (without getting into boost) just to make sure it would be safe to drive 2 aways away for tuning.. After I saw that it was gonna be friendly to drive I pulled off the cog belt so that the sc would not be spinning and drove my car to work a couple times. So a couple nights ago I installed the walbro 255 and drilled out the swirl jet and regulator. Drove the car around a little and it seemed fine.. Idled a little high and sometimes would get lean at idle (high 15s and at cruise speeds it was running a little lean, 15.1 ish. Okay so last night I put the sc cog belt back on and took her down the road about a 1/8 mile and soon as I barely throttle it the car falls on its face. Turn around and take it home. (Also w cog belt on at idle its running extremely rich. My aem digital wideband was reading like 10 and even below at idle. Anyway I take cog belt back off and drive down the road about a 1/4 mile and she's running fine.. Turn around and on my way back I notice my heat hand gradually rising as I'm pulling in my driveway. Turned heat on and it's blowing cold. Lots of pressure on my top coolant hose(didn't check the bottom) checked oil and no sign of coolant in it, checked coolant and cap, no sign of oil. Tried to smell the exhaust for coolant odor and It may have smelled a little odd but I don't think it was really anything out of the ordinary.. I'm going to do a compression test on it after work today. And see of this tells me anything

 

Check to see if your thermostat is stuck. Also, you may have improperly installed your fuel pump, but it's hard to tell because it looks like you have several problems compounding.

 

I'm pretty certain my pump was installed correctly according to the "how to install walbro" I took my time and follow ever step w no issues. Okay say my thermo is stuck and that's causing the running hot issue. What could be causing the car to lose its load, only w supercharger belt ON, belt off she runs fine without falling on her face, aside of running hot. I just checked compression on two front cylinders and try both read around 5psi. I seriously hope the guage is messed up. I just went and go another one and on my way home now to check it again

 

5psi...yikes. That car would be running like complete chit with or without the blower.

 

Alright the guage was definitely BROKEN. Checked the car again but only had time to do one cylinder and it was showing around 70psi and the engine was cold.. I let the engine warm up a little afterwards and the bottom hose is cold, top is hot. I assume this will be thermo or water pump causing me to run hot, but I'm still set on thinking I have a blown head gasket. I still can't understand how the car would run fine without the blower and fall on its face w the blower on considering it didnt cut out the last time I had the sc on. To replace the water pump i have to take the supercharger back off cause its all in the way. Hoping gonna get off work in time to do it tomorrow.

 

Even if the motor was cold, 70psi is retarded low. With 126k miles, I'm at 170 on one side, 165 on the other. Did you hold the gas pedal all the way down?

Also, you're diagnosing your problems entirely incorrectly. You have no idea if the water pump is dead. You're immediately jumping to a DIFFICULT solution before eliminating all the SIMPLE ones. Try burping the coolant system or replacing the t-stat first, check compression on all cylinders, etc.

 

Not real "simple" to replace thermostat when I have to remove sc to get to it. I just don't see how all these problems occur over one night. Monday I was driving the car fine. Also I checked psi just to get a general idea and make sure it wasn't truly at 5psi which I doubted. When I have time tomorrow I'm gonna check all 6 the right way by warming the engine, removing all plugs, unhooking the injector plugs, and opening the throttle body all the way open. I ran out of time to take all these steps earlier to get a good true reading. My car has roughly 90k miles

 

Also I can try bumping the cooling system but I've never had a single cooling issue (car has been in family since day one) I guess I can't see how air somehow just jumps inside the cooling system. But who knows

 

If the bottom hose is cold then that means the thermostat isn't opening. The way this thermostat is designed it's very rare for them to fail. What usually happens is an air bubble forms right behind the thermostat which keeps coolant from touching the metal spring therefore it never gets hot enough to open up. It's a very common problem on these cars. I use a spill free funnel so the coolant fill is higher than the heads and you can actually rev the engine a little to move the bubble through the system with it on. I would re-bleed the system with a spill free funnel until you feel the bottom rad hose getting warm again. The water pump is all metal and driven by the timing chain so if it fails you will hear the metal fins destroying your cooling system and if it stops spinning so do the cams so the water pumps never fail.

As for being rich, increasing the flow with the walbro would cause that.

 

Okay that may explain the overheating issue, but im only extremely rich with the sc cog belt on, with the cog belt off I'm running a little lean. Should this not the the opposite way around? Also I still don't understand what's causing the car to lose its load only when the cog belt is on.. Sc is only forcing in air, not fuel. Makes no sense to me, again it didn't do that before installing the walbro and it still doesn't do it when I have my cog belt off. Just crossed my mind that another thing I did was reset the ecu and the throttle body. I doubt either would cause my issues but just throwing it out there

 

Your car is falling on its face because of the sub 10 AFR. This would definitely be a result of the blower since the car will be in a different part of the fuel map. You need a tune or you are going to ruin something.

What engine management are you using for fuel?

Did you remove any of the coolant system to do your install?

The compression is crazy low though. I had 150psi on my 8.5:1 built motor. Stock should be higher than that or equal if it is an older motor.

 

Hey man thanks for your reply but NO the sc on stock map is not causing it to fall on its face. I know this because i ran it for a few days before to make sure she was gonna be worthy of making a 2 hr trip to the tuner and to work out any kinks i might have before getting my car to the tuner. Not to mention most of the air escapes out the bypass valve. Anyway I figured out my issue today. turned out to be pretty simple.. I had an intake plenum gasket leak.. Fixed that now she's good as gold. Hopefully get her tuned next week... Thank you all for your time.

 

Plenum leak would replicate the same thing by leaking measured air so that is a good find. Glad you got everything squared away.

 

Yes sir I always appreciate all you guys for your help.. Kinda funny how I found out I had the leak in the plenum.. I have a kinetix velocity and while trying to figure out my issue I was letting the car idle and just happened to lean over with one hand to prop myself on my plenum. When doing so I noticed a change in the air intake sound. Did it again a couple more times to verify I was really hearing it. Took it off and replaced seal.. Huge smile on my face. I was pretty afraid I was have some head issues.

 

Those intakes are known for leaking so it's not very surprising that it was the culprit.

Have you investigated the cold lower radiator hose with overheating temps? Low a/f would cause the car to run slightly hot but it would not explain the cold lower radiator hose. That is something I would be more concerned about than a/f since you can quickly destroy your engine with too much heat.

 

Actually the intake was the whole reason the car was running hot.. I haven't had a single issue out of it and have driven it daily since I fixed it.. Bottom hose stays as hot as the top now.. I found out that the reason everyone has leaks with their velocity plenum is because the oem gasket will NEVER seal off.. You HAVE to use the gasket that kinetixs sales specifically for that plenum and I didn't know that :/.

 

ya, I think it's thicker to help seal the imperfections of the sealing surface on that intake.