Code 33 (HELP)

[pomai]

88 K-5 Blazer
New motor, first start, it starts right up, runs ruff and unable to raise idle with out it bogging. I don’t know how else to explain it.

Flooding, lots of fuel, wet with fuel, black plugs

Once it starts and dies I’m unable to restart it without holding the throttle wide open.

Showing a code 33, (MAP) so I installed a new one, cleared the code, still showing 33.

Help Please!

Thanks, Ed

 

[dave w]

I think maybe using a Noid light to see if the injectors are actually pulsing at the starter cranking speed would be my first step in troubleshooting.

I'm thinking there is to much fuel being sprayed (pulsed) from the injectors.

Maybe try unplugging one injector? I've had an injector quit spraying fuel, but the engine would run. If your getting to much fuel from the injectors, then maybe if one injector is unplugged, the engine will run?

Once I worked on a TPI that had a short in one of the injector wires, engine ran, but died after about 30 seconds.

dave w

 

[pomai]

Yes there is a lot of fuel being sprayed into the intake. when I try to start the second time, i have to hold the throttle wide open for it to start. Wet (fuel) black plugs.

Thank you for your help, I need it.

Ed

 

[dave w]

pomai,
It's not easy to troubleshoot over a keyboard.
I don't really understand what would cause the injectors would spray to much fuel.

The only way I think the injectors would spray to much fuel would be if the PROM Chip in the computer was reprogrammed.

Has the computer PROM been changed?

dave w

 

[pomai]

Yes, it’s a custom chip by Harris Performance. I just changed all the plugs and connected a vacuum gauge and am getting approximately 5” of vacuum.
still showing a code 33.
It was able to idle a little but as soon as I pull on the throttle linkage it starts to die.

I understand that is is hard to troubleshoot over the keyboard.
I appreciated all the help.

I’m worried about what all this gas is doing to the rings. This motor was rebuilt 3 time with 0 miles. Below is the engine specs.

Thanks, Ed

1988 Chevy Full Size 4x4 Blazer​

Engine is a late model factory roller 4 blt main block, 383 rotating assembly, scat crank, 6” rods, JE forged 40 over pistons, World S/R torquer heads. JBA shorty headers

Cam is a Roller Comp Cam 08-304-8, .500/.510, Duration 266/276, Lobe Separation 114,.1.6 roller rockers.

Throttle body bores are 2” by Xtreme-FI from eBay along with there intake manifold bored the same.
MSD Distributor and Coil.
3” Cat Back Exhaust system
Delta Flow- Muffler

www.tbichips.com
Computer chip
High Pressure fuel pump
Regulator spring

www.Bowtieoverdrives.com
700r4
Xtream Package

www.cfm-tech.com
CFM GM TBI Power Plate (bored 2”)
Hypertech Power Charger
TBI Injector Spacer
Adjustable Fuel Psi Regulator
3 wire (heated) Oxygen Sensor
15 psi Fuel Gauge

www.TBIPARTS.COM
New 454 Flow Matched Injectors

 

[pomai]

I'm using NGK UR4 spark plugs. should I be using something else?

 

[dave w]

Ok,
That is very useful engine build information.

So maybe I think try adjusting the fuel pressure down from 15 PSI to 12 PSI.

dave w

 

[Thunder]

Your vaccum is wayyyy to low. You have a massive vac leak somewhere. That is why you are getting a code 33 and so much fuel.
Only 5 in hg vac at idle will make the ECM think you are under hard acceleration and dump more fuel. Trouble Code 33 indicates that the MAP sensor because of the low vacuum reading, is reporting more air is entering the engine than makes sense based on RPM and TPS position.
Your vaccum should be at least 15+ at idle unless you have a very hot cam. Your cam is not hot.
The cam you have in there is a low/ midrange computer cam so it should have a high vaccum at idle around 17+ in HG
Check for vacuum leaks. TB base gasket, Intake manifold gasket are problem areas.
Are the valves adjusted right?
A plugged convertor can also cause low vacuum reading.

 

[GMC Truck]

Check the vac line to the power brake unit. I made that mistake once and it drove me nuts!

 

[pomai]

Your vaccum is wayyyy to low. You have a massive vac leak somewhere. That is why you are getting a code 33 and so much fuel.
Only 5 in hg vac at idle will make the ECM think you are under hard acceleration and dump more fuel. Trouble Code 33 indicates that the MAP sensor because of the low vacuum reading, is reporting more air is entering the engine than makes sense based on RPM and TPS position.
Your vaccum should be at least 15+ at idle unless you have a very hot cam. Your cam is not hot.
The cam you have in there is a low/ midrange computer cam so it should have a high vaccum at idle around 17+ in HG
Check for vacuum leaks. TB base gasket, Intake manifold gasket are problem areas.
Are the valves adjusted right?
A plugged convertor can also cause low vacuum reading.

Brand new converter, but when the engine did start the
Exhaust was spitting out black soot. I don’t know what to call it. I’m concerned about the cylinders being washed out and running the rings. It’s a new motor. I started it a total of 6 times for approximately 30 seconds with the last time for approximately 1 minute. I give up, I’m taking it to the shop, but know one over here are very confident about it. One shop wants to bring the fuel pressure back down to 11 psi, but shouldn’t this combination be capable of the 18 psi? Brian Harris at Harris Performance has all of the engine specs and used it for the chip which he programmed

When I asked him if there is to much fuel pressure and should I lower it or put the stock ship back in.
Below was his response.
the extra fuel is only under boost. it should run pretty much ok without the supercharger. There is extra accelerator pump fuel to compensate for extra air rushing in with that supercharger connected which may cause little laziness with the throttle tip in. Go ahead and run it with the new configuration and chip and it should run decent.

Right know I wish I was in the mainland with my blazer, I know you guys up there would be able to figure this out in no time. We here in Hawaii are years behind you guys.

Its been suggested to me many time to throw all the EFI away and to put a carb in. I’ll get to the bottom of this. I’m staying with the EFI

But thanks everybody, I really appreciate all your help and comments.

Aloha!
Ed

 

[pomai]

Check the vac line to the power brake unit. I made that mistake once and it drove me nuts!

I’ve been listening for a Vacuum leak to the power brake unit and I cant here anything.
I don’t have the driver fender on so I’m able to stand on the tire and get close to everything. And I cant find a vacuum leak anywhere.