gcthree

I've posted earlier about my extreme rich condition after a viton vac hose job and elimination of AWS, TB coolant, EGR, and double throttle plates. Start it up, and it's black smoke, rough running, heavily sooted plugs....a disaster.

Went back to the hose job, and checked every hose. It's all nice and snug (the viton tubing is awesome!), and no leaks. Replaced the UIM/LIM manifold gasket, TB/UIM gasket, and TB o-ring. The MAP sensor is hooked-up, and I cheked the TPS settings using my PFC to .4v and 1.00V. I also replaced the coils and wires, and cleaned the plugs. Start it up- same crap.

There's enough smoke to choke you in the garage- it's definitely rich. I need to put a timing light on each plug wire to ensure spark- and haven't done that as yet.

Is it possible that something went horribly wrong with the mapping on the PFC during the work I was doing? What do you think about replacing the PFC with the stock ECU just to start it up and see what happens? ( I have plenty of mods, so I'll not load-up the motor- just idle it and see what happens) I didn't put resistors in the harness where I removed solenoids for elimated systems- what's the effect of this?

How about a stuck injector? The duty cycle on the PFC at idle is around 12%- will duty cycle reveal a problem here?

I'm running out of patience with this car......

z4csl428

i dont know about going back to stock but if it works ill take your PFC ...

littlemilla3

iTrader: (1)

It won't hurt anything as long as you don't put any load on the engine. It will run even more rich if you don't have stock injectors.

gcthree

I'm running stock 850cc primary injectors, and 1300cc secondaries- why would it run richer with the stock ECU?

ptrhahn

iTrader: (9)

Bob,
The "stock" primaries are 550's... not 850's. At idle, they should be the only thing running... and you should be able to start the car and idle it if they're indeed stock 550's....

DaleClark

iTrader: (55)

Is the PFC set up for the 850cc primaries? If not, it's gonna run WAY rich. Same with putting the stock ECU in for troubleshooting.

Think about it - when you put the larger primaries in, you have to scale back the pulsewidth that the injectors get. The 850's are approx. 1.5 times bigger, which means with the same pulsewidth 1.5 times the fuel is injected with every squirt. More fuel = eye burning.

Also, you didn't mess with the black filter that's in the line going to the MAP sensor? I've seen people assume it's a check valve and put a check valve in its place, which is WAY wrong. The MAP sensor has to see both vacuum and boost. Not saying you did that, but I'm checking every angle .

While you were in there, did you mess with the injectors? A torn O-ring on the injector can in theory bypass pressurized fuel around the injector body and firehose fuel into the engine.

Dale

gcthree

Duhh. Thanks, Peter, they're 550's. My mistake....can't believe I did that...

Dales, The PFC is set-up correctly for the injectors. The car ran fine in the past (it has never made the power it should have with the modifications I have, however. But that's another story...). I did put new tubing on the MAP sensor, and put the filter back in correctly. But, here's another little bit that might help. I adjusted the TPS, and removed the line to the MAP sensor while doing it. In haste, I started the car up, and then realized my oversight. I plugged it back on the UIM, and the car ran equally bad with and without the MAP sensor connected. Could it be a bad MAP sensor?

And no, I did not remove the injectors.

Thanks for all the help.

gcthree

Dale, sorry for the typo....

If I were to plug the stock ECU back in, will the 3 harness connectors that are now not attached (and no resistors) allow it to run? It will throw codes, of course, but apart from a warning light, it will run the car, right?

DaleClark

iTrader: (55)

The ECU should run fine with the solenoids unplugged - it will store a code, but will only throw a fit if you have something crucial to the car running, like the MAP sensor, TPS, water temp, CAS, etc. disconnected.

Dale

gcthree

Great! That's the answer I was looking for.

Failing that, I'm also going to check the pressure sensor per the FSM.