Hi there,

I am very confused at the moment about that way the car is behaving. I recently did a re-build on the motor and started giving it some mileage using the same MAP I had previously for 850cc x 4 inj.
The car initially drove well, no problems apart from the light throttle issues I had before after installing the 850cc primaries. All of a sudden, one morning I started her up and she idles rich to the point where the plugs start to foul and then one plug goes out , so I'm idling on 1/2 the motor. A couple days before I went on a drive for about 60miles or so, but out of boost and nothing more than 4000rpm, as i breaking in the car, drove well went home, parked in the garage till now... So, I switch off, pull the leading plugs and both are wet, but the front plug is TOTALLY wet, and the rear plug is slightly wet. I ran a check on the fuel press yesterday and its normal around 37-38psi at idle/static press. So, its pointing in the direction that the either the ECU out to the inj. or the inj. itself is screwing around. What do you guys think ? I'm considering going back with stock 550cc primaries, so that I can get back my smooth driveablity and upgrade the secondaries to 1300cc...
I'm running a Walbro 255L, stock fuel rails/ stock FPR, stock motor, 3" exh., ARC cool air box, OEM SMIC for now, planning on going FMIC soon.

 

check for a vacuum leak

 

Vacuum is good, how can I verify if the coolant sensor is failing ?

 

My car was idling at 12 and they couldnt change it in the tune. Come to find out the resisters I had werent providing enough resistance for the low imp injectors.

 

First verify that the map in the PFC matches the version that you saved from before.

If OK and since it was 4X850 before and is again, then you hosed something on the install. First check the map sensor as that would flood you out if not working or does not have a hose to it.

 

Hi Chuck,

After the rebuild it ran as before, idle was normal,actually drove about 70 miles or so , with no shutdowns whatsoever, while driving I didn't go into boost, as I'm still breaking in the motor, and wasn't passing 4000rpm. Parked it up for a couple days. Then when I went to start it up a couple days after, this fuel problem appeared and is still here. When the misfiring starts, I switch off, pull out the leading plugs and they r wet, but the Leading 1 plug is totally wet, if I replace that plug alone , it will start and idle normal for about 10 secs or so, then starts to foul up, then I have to pull out again and repeat. Initially, I was running BUR9EQ's all round, but then decided to try 7's on the Leading and that worked for a while , but then that also fouled up too. I'm going to do a check on the L1 coil and see if that's coming up with a problem. other than that, its looking like the injectors are playing the fool ! If it were the coolant sensor, wouldn't it be indicated in the sensor check page ??

 

I don't believe a failed coolant sensor would enrichen to the point you are seeing. Looks to me like one of the injectors have failed open or possibly the fuel pressure regulator has failed and causing high fuel pressure.... I would start the diag. in the fuel system.

 

Hi, I already ran a check to verify fuel press. and I'm getting the normal 37-38 psi, so that rules out the FPR being a problem.....

 

Ok, it seems like I've solved the problem. but only when I assemble back up the rats nest etc. and start, then I'll know for sure, but it appears that the lower O-ring on the front primary inj. had a lil cut. So I replaced the both inj. with new O-rings and stepped back down the 550cc inj. from the 850cc.... Now I should get back my driveablity !!