Thread: Possible maf problem

Sounds like the IAC valve on the back of the plenum, and/or make sure the MAF plug is plugged in properly, Regards Frank.

Are you sure you didn't put the advance pipe on the retard side?

I would be very surprised if a MAF adjustment like you did would cause such a dramatic difference. BTW, MAF adjustement should always be done with an exhaust gas sensor to trim to idle unburnt Hydrocarbons.

You sure you didn't disturb the ECU water temp sensor?
Regards Philip A

if I do the oxygen sensor retro fit will the ecu stop reading the maff cheers.

Yes when the o2 sensors are warm, but all sensors should be working properly. The ECU will read the MAF on start up until the O2 sensors are at temperature and if it is that rich caused by teh MAF you may have flooding problems.
Regards Philip A.

Originally Posted by PhilipA

Are you sure you didn't put the advance pipe on the retard side?

I would be very surprised if a MAF adjustment like you did would cause such a dramatic difference. BTW, MAF adjustement should always be done with an exhaust gas sensor to trim to idle unburnt Hydrocarbons.

You sure you didn't disturb the ECU water temp sensor?
Regards Philip A

I am 100% sure that i didnt put on retard side checked with timming light
but i think some one had played with the maff was on .07v I shall also check the resistance of the temp sensor do you know what it should be thanks
oh and also in the process of getting all the stuff to do the oxy sensor conversion do you still think it was worth it also thanks for the tutorial on that it is really good.

Originally Posted by Tank

Sounds like the IAC valve on the back of the plenum, and/or make sure the MAF plug is plugged in properly, Regards Frank.

I am also having new problems with my iac i have cleaned it and it is still shocking will idle for 5 mins fine then it will hunt really badly and eventually stall does this mean i need a new one cheers

I am 100% sure that i didnt put on retard side checked with timming light

Huh?
Static timing or idle timing has nothing to do with vacuum advance on a RV8. As it is ported advance it is only active at small throttle openings at medium revs. it is very difficult to see if it is working. the only indicative way is to suck on the pipe to vac diaphragm and see if it holds vacuum , and suck on the pipe connected to the vacuum port to see if it is clear.

resistance of the temp sensor do you know what it should be thanks

About 300 Ohms at operating temp. Also pull the connector off and check the contacts are clean.

oxy sensor conversion do you still think it was worth it

Yes as it compensates for wearand makes sure the engine runs lean at light throttle, and makes a 14CUX run as well as it ever will.

5 mins fine then it will hunt really badly and eventually stall does this mean i need a new one cheers

Er more likely to be crook plugs, leads, dizzy cap, rotor or maybe old drooling injectors.
IAC is more likely to cause stalling when putting in D or stalling when coming to a stop or when revs drop first time.

Originally Posted by PhilipA

Huh?
Static timing or idle timing has nothing to do with vacuum advance on a RV8. As it is ported advance it is only active at small throttle openings at medium revs. it is very difficult to see if it is working. the only indicative way is to suck on the pipe to vac diaphragm and see if it holds vacuum , and suck on the pipe connected to the vacuum port to see if it is clear.

About 300 Ohms at operating temp. Also pull the connector off and check the contacts are clean.


Yes as it compensates for wearand makes sure the engine runs lean at light throttle, and makes a 14CUX run as well as it ever will.


Er more likely to be crook plugs, leads, dizzy cap, rotor or maybe old drooling injectors.
IAC is more likely to cause stalling when putting in D or stalling when coming to a stop or when revs drop first time.

Hi phillip a I forgot to mention that i sucked on the end of the hose when i had timming light on and i also have a new dizzy cap and rotor and leads are only six months old but plugs have probly done 30000kms now so due for a change just orderd a new set of injectors the ford ones bosch gen II I will also check temp sender on friday after work I shall change plugs and injectors hopefully next weekend when I plan to fit 02 sensors and also thanks again for your help it is very much appreciated