Thread: 14cux guru's backfire issue.

Was the cam from a carburettor car?
If so it probably will not work with injection as the vacuum signals are all wrong. Injection cars need mild cams with different inlet and exhaust phasing than carbys.
Removing the temp sender will make the injection run very rich ie full choke, and this may compensate for the weak vacuum signals.

Unless you find out the cam is for injection, then this has to be the first base, as nothing else you will do will help it.
Regards Philip A

thanks phil.. i never thought that far into it. the motor was in a running RRC but it was running a haltech E6X (that i now have) as the ecu, it had all the OE injectors etc, minus the stepper motor and AFM (the best bits to leave out)
thomas said it didnt idle that well but its done quite a bit of touring, the last big trip was to cooma for the 60th.

ide just like to get it running right for now till i have the time to pull the OE ecu and re fit the haltech.

cheers phil

Well a Haltech works with a MAP sensor not a MAF and also can be tuned more widely to mask problems.eg injection duration/richness at low revs.

Usually a MAF like in the 14CUX is more accommodating to engine changes from stock than a MAP but maybe the Haltech can be richened to mask the low rev problems. ie If the MAP could be set up to run at first then it may be able to handle the cam better, but if any further changes are made the Haltech would have to be retuned .

Regard sphilip A

Phil, what is the timing set at? Sounds retarded to me. Unplugging the temp sender will richen the system in default, masking a late ignition timing problem somewhat.

At 10.5:1 compression, and a standard dizzy, I would try 5 or 6 degrees BTDC to start with.

JC

What Justinc said, also check the Vacuum advance and the centrifugal advance is working, Regards Frank.

Originally Posted by justinc

Phil, what is the timing set at? Sounds retarded to me. Unplugging the temp sender will richen the system in default, masking a late ignition timing problem somewhat.

At 10.5:1 compression, and a standard dizzy, I would try 5 or 6 degrees BTDC to start with.

JC

ive been at 12,6 and now 4 btdc, with really no change at all. as for the vac advance...there isnt one, the base plate is locked up to prevent movement. im getting another dizzy next weekend for a try. may as well just change the valley gasket anyway...after i sort out what the cam is

cheers phil

Originally Posted by discowhite

ive been at 12,6 and now 4 btdc, with really no change at all. as for the vac advance...there isnt one, the base plate is locked up to prevent movement. im getting another dizzy next weekend for a try. may as well just change the valley gasket anyway...after i sort out what the cam is

cheers phil

Sounds like weak ignition to me, you need more spark with higher comp. Try swapping the ignition module, if it's the one on the dissy I have chucked out a number of them over the years. When I get a chance I will post up my Bosch module conversion, its been trouble free on a number of cars.

Why no Vacuum or Mechanical advance, the standard LR Computer only works the Fuel injection, you have No advance at all, the Haltec adjusts advance + fuel injection, so either put a Functional LR dissy in or set up the Haltec, Regards Frank.