91 1.6L NA weird problem

[coke]

Hey guys. 91 1.6L all original except has rebuilt pump. Only thing isn't rebuilt on fuel system is injectors, though I did install new nozzles in them.


I have an interesting problem. When I try to go to WOT with the car in neutral, the engine will start to skip a little and puff white smoke out. It isn't a steady stream, or anything like that, and it only seems to do it in neutral with no load going from idle to WOT.

I've tried all different timing settings, even tried a set of injectors (Though they were used and probably in worse shape than the ones I had in it) to no avail. I cannot get the skip and little puffs of white smoke to go away. What are your thoughts? It starts and runs great, mileage isn't great but neither is the sub zero temperatures we have here and long warm up times. Thanks.

[8v-of-fury]

that is interesting.. there really isn't much difference in revving in neutral and under load. Approximately what rpm does this start in at? Is the engine at operating temps while doing this?

Also a tip on battling warm up times.. you could idle a diesel all day long in frigid temps and it probably wouldn't get up enough heat to open the thermostat in the water pump. If you have the correct weight oil, you should really only need 60 seconds tops before driving. Running a 0w synthetic will allow the oil to be pumping instantly, and you could drive away in 45 seconds of warm up. Obviously,  your not gonna wind it up to 5k.. take it easy and it will be fine. The reason they don't warm up like a gas engine is because they are almost twice as efficient at turning the power created by combustion in to turning the wheels, and little is lost to heat. Hense the long warm up times.

Weird bout the smoke only happening in neutral though..

[coke]

Either that or I'm going deaf or don't notice it when there is a load on it. As far as the warm up times go, yeah, I understand what you're saying.

Probably around 4-4500 RPM is where I'm seeing it. Its hard to explain, I wish I had a video of it. I don't know what to do other than replace injectors but I was hoping someone might have had the same issue.

Yeah, engine is at operating temp while doing this.

[Rabbit on Roids]

starts popping and puffing white/blue smoke? you probably wont notice the pop too much tho, unless you have some sort of aftermarket exhaust. my audi pops and puffs if you rev it in neutral. it almost sounds like a dead hole, but instead of having almost no sound from that hole, it makes lots more noise than the rest.

nobody could ever tell me what my problem was either. i think its a tired engine coupled with tired injectors myself. because like you, my fuel pump isnt that old either.

[burn_your_money]

It could be your valves floating, or your hydraulic lifters not being able to open the valves enough.

You really shouldn't be reving the snot out of the car with no tach and no governor.

[coke]

Well until this morning I was unaware it had no governor.  And it isn't at WOT, its near WOT where its doing it. Did it on the old pump too.

[8v-of-fury]

Well until this morning I was unaware it had no governor.  And it isn't at WOT, its near WOT

Near WOT on a pump without a governor, could probably very easily spin that engine up to 6500rpm in neutral. I think it was you Tyler, that told me the stock pump will provide enough fuel to rev the engine to 5300 in neutral... a little more fuel and 6000+ would be easy to sustain.

I would not be too worried about it.. If your getting good mileage, not burning oil or coolant. Is there really more to ask for? lol

[coke]

Yeah, I didn't know the super pump didn't have a governor. But it still doesn't change the fact it skipped and smoked before. Giles suggested the compression from the engine is forcing my faulty injectors to open up allowing fuel to spill in. Makes perfect sense to me. Guess its time to get remans and put this problem to rest.

[truckinwagen]

superpumps are governorless?

I assumed that something was done to them, but what? solid rod?

[burn_your_money]

Secrets They do have governors still but you will blow the engine way before you hit the governor. It's a good thing you didn't blow your engine then

How much air do you have being drawn into the pump when you are revving it that high?

[truckinwagen]

Secrets

I figured as much...

[coke]

No air at all. The fuel system is absolutley crystal clean.