FASTR

Hey guys.. I need some help from you LS1 experts
I recently purchased a 98 formula M6 with 80k miles on it.

I installed Bilsteins, new rims and did a full tune up: MSD wires, NGK irridium plugs, Delphi O2 sensors. I also did a Volant CAI, Pacesetter FL headers, TSP ypipe and SLP powerflo exhaust.

99% of the time the car runs great. BUT, About once a day or so, regardless of how many times I have turned the car off or on, the engine will start to bog and flood out as I am taking off in first gear. Sometimes it even takes off perfect then starts flooding out before I can get into second. I push in the clutch, and the engine tries to regain idle but cant properly. It just idles rough on a few cylinders. I hit the gas pedal to the floor and it will chug cough then rev right up explosively. You can then of course smell all the fuel in the exhaust. I rev it up a few times hard to clear it out and then it will run perfect. Usually for the rest of the day. The problem only happens right after I have started the car, and doesnt happen everytime though. (sometimes I let the car warm up awhile, sometimes not. Doesnt affect the problem either way.)

Anyone have a strange intermittent problem like this? Fuel pressure reads fine, but then I cant catch it when the problem actually happens. I could just start replacing a bunch of sensors, regulator, fuel pump etc. But that sure gets expensive quick.. I did clean the MAF and the throttle blades and installed a new air temp sensor to no prevail.
Thanks for any help you can provide!

Jer

johnny6

I had a similar problem a few years ago, turned out to be a loose battery cable. Everytime i would start the car it would barely idle and almost die out, what was actually happening was the PCM was re-learning itself after almost each start up because of the loose cable, give that a shot before you try anything else. Also check for corrosion etc. etc. around the cable.

Marc 85Z28

Possible coolant temperature sensor reading incorrectly. If you do find that to be the cause, remember that the 98 cars are unique, and you will need a 3 wire temperature sensor.

FASTR

Well, I wouldnt have thought to check them because I had just put the new battery in a few weeks ago.. but I did check the cables. They weren't what Id call real loose, but they did take just a little bit of snugging. I drove the car a half dozen times doing Christmas shopping etc. Not a single problem. I didn't drive it today because of all the ice on the road, but I think that f-n did it. I cant believe it, LOL. (and knock on wood).
Ill verify for sure tomorrow with some more driving. (I did notice that when I cleaned my MAF that someone had yanked the honeycomb out, so I bought a new factory MAF from NAPA). Ill put in in tomorrow for good measure.

Thanks for the help!!

FASTR

Well its not fixed yet. I did a bunch of running around again today.. it did the bogging thing once. I was able to get it to stop by turning the car off and restarting it quickly. Reved it up and then no more problems. Wierd.

I did put a new MAF on it.. runs much better. Idle is smoother and the driveability is noticably better.

I think when I flush the cooling system Ill put a new temp sensor in along with a new thermostat and see if that does anything.

johnny6

Did you get it scanned?