Engine light comes on

[Nitro Worms]

Hi, am running ose12p on vp v8 and had trouble connecting so ended up loading bin into other side of nvram and using jumper pin.
Been going well for a while but last few trips to town it will randomly have a big engine stumble like you turn the key off for a half second and back on. Its done it at about 80km/hr coming up a hill and its done it down a hill at 60km/hr. The engine light comes on for about 20-30 seconds afterwards and it reveals code 33 and 34 at same time. I cleared codes and after the miss the sames ones come back up.

Where should i start looking?
Any ideas appreciated thanks.

[Holden202T]

i'd be getting a data log when it happens, might point you in the direction of the issue, i'd also be checking the map sensor wiring and vacuum hose are not dodgy.

[wozza]

Maybe check the map sensor,wiring ect
Code 33 - Manifold Absolute Pressure Sensor (MAP) - Voltage Too High
Code 34 - Manifold Absolute Pressure Sensor (MAP) - Voltage Too Low

doh Holden202T beat me to it
Ill add is the map sensor the right one http://www.robietherobot.com/storm/mapsensor.htm

[Dylan]

That's MAP sensor codes. I'm tipping the stumble you are getting is fuel related due to the MAP reading at the time. Get a datlog and see what's happening at the time. Or get a license for Tazzi's software and get the freeze frame data.

Got a spare sensor you csn try? Check over the plumbing too.

[Charlescrown]

Check the 5 volt supply to the map sensor there may be a problem with one of the components on that line or the ECU. A log like 202 said is the best thing to help analyse the problem. I have seen where a simple $2 cigarette lighter usb adapter was used to power the components when the ECU failed and it worked a treat.

[Nitro Worms]

ok, Ill have a look at the wiring around the map and hoses. Its a 2 bar map havnt got a spare. Ill try to log and see if i can catch it.

[Charlescrown]

2 bar MAP. Is it turbo or supercharged? If not why are you using a 2 bar map?

[Nitro Worms]

Yeah its a boosted 383 holden, I may have found the issue. Went a few days without playing up then went to start it and noticed fuel pump didnt activate at key on 2 clicks one morning and i jiggled the fuel pump relay main power fuse and it came on. Looks like a dicky connection time will tell.