First (legal) drive and engine issues

byroncobra · #1 (**permalink**) 05-09-2011, 04:22 AM

Just read your comments Cameron, wow that would have taken some lateral thinking...
My headers are real close to the rear brake lines and the thought crossed my mind that the fluid might not like the heat and lead to fading.....the fuel lines are well away from a heat source though.

Zedn · #2 (**permalink**) 05-09-2011, 04:30 AM

Does your ecu use a cylinder head temperature sensor? I would be looking at what ever it uses to sense engine temps.

Other things to try would be disconnecting your O2 sensor and seeing if it makes a difference and also the MAF.

suthol · #3 (**permalink**) 05-09-2011, 04:48 AM

Don't over analyze things and look at the most simple things first.

One of our clubbie guys had a car that had been going like a train but suddenly wouldn't start, he was off to buy a new starter motor.

Turned out to be an HR joint on his battery isolation switch.

Same car started to stall when turning left even with half a tank or more, must need a new pump the lad said because it sounds funny.

Funny was because it was pumping bubbles, turned out to be an in tank prefilter being clogged by the gunk that RON 98 can produce.

A quick blast with the compressor and it was smiles all round once again.

In both cases the forum help had him almost building a new car.

Another mate couldn't get a 351 to run smoothly after new plugs and leads, more wild ideas were offered.

All he'd worked on in the last 5 years were Chev.

byroncobra · #4 (**permalink**) 05-09-2011, 05:43 AM

Suthol, one learns very quickly that info kindly offered on forums is not all gonna be the best, however, I've found on many occasions that I can screw around looking for the obvious, then bung a post on a forum, and get a quick experienced opinion on finding a solution

Better go and check the in tank filter now......

Zedn · #5 (**permalink**) 05-09-2011, 05:51 AM

If it was a filter it would be the opposite.

The problem you are having most likely relates to an input to the ECU or the tuning of the ecu. If it runs ok when its warmed up then the computer is either getting an incorrect temperature input or it is not tuned correctly for below operating temp.

My 2c.

Aussie Mike · #6 (**permalink**) 05-09-2011, 05:42 PM

Might be a dodgy MAF sensor. When you are just driving around normally the ECU uses the Mass Air Flow, RPM, TPS, MAP and O2 sensors to calculate your injector pulse width. This gives the best economy, emissions drivability etc. When you stick your boot down the ECU usually goes into speed density mode where it just runs off RPM, TPS and MAP and ignores the rest. At least that's how it does on an LS1 ECU.

Cheers