redlineracer

I start the car when its cold and it spudders for a bit. I haven't heard of this. I Changed the Plugs it got better but it still does it. Just wondering if anyone has experienced this before.
88 vert manual trans.

I know the car sat for a while before I bought it.

jjwalker

My full range TPS was all way out of range. I didn't know it did anything much with fuel enrichment at all but it does.

I replaced it 2 days ago and now my car starts fine.

Mine would start up and sound as if it was running on one rotor and sputtering. Clouds of fuel came out of the tail pipe too. It always started fine warm though.

redlineracer

That's it thats what i'm experiencing. So a new TPS.

FC3Srotarypower

redline, did that effect the driving at all?

jjwalker

If it is the full range TPS, then it won't have any noticeable effect on driving until you swap it. It seems to fail so slowly you don't notice it. My car got more peppy with the new sensors installed, I would assume, because my car wasn't running pig rich.

My problem with the full range was somewhat found by accident, and somewhat by doing extensive research in the FSM as to what exactly it controls. I was always under the impression that the full rnage only controlled the OMP on S5's but that is dead wrong. The open loop fuel maps also mapped to the full range TPS.

The reason I was only having issues when starting and running cold is because the thermowax unit would open the throttle into the "bad" range of the full range TPS. when sitting cold, the full range TPS was reading 13Kohm which is...well....way the **** out of spec. However, when it was warm outside, the sensor was within spec and wasn't extended far enough to be in the "bad zone".

Edit: ****, I just realized he said 88....which is an S4 right? I think S4's have just a single TPS. May want to check it anyway because that single TPS on the S4 does somewhat the same thing the full range on an S5 does if my knowledge serves me right.

FC3Srotarypower

man i have so much to learn. i barely know what half that means, and ive been involved in cars for quite some time.

redlineracer

Once it warms up the sputtering goes away. Car runs fine. I noticed that it does it when it really cold out. I was told it may be a coolant seal. Oh well small price to pay to be a rotor head.

jjwalker

I had the same issue and just found out what it is. Slight coolant leakage into the combustion chamber temporarily fouling the plugs until they dry off.

I am having to rebuild the engine.