rolltide0323

My wife just bought an 84 with crossfire injection. It takes a few cranks to get it started and when it does start, it appears white smoke comes out of the exhaust. It has a rough idle for about 15 seconds or so then runs good. I also noticed what appears to be oil/soot coming out of the exhaust. Any ideas on what could be causing the smoke and rough idle. Thanks for any input. I can't embed the video so i will post a youtube link.


https://www.youtube.com/watch?v=HXIV...ature=youtu.be

Jay7199

The video is pretty low quality, hard to gauge the amount. was the car cold when you started?

ANTI VENOM

Since I don't know you, don't know what you know, I will just start from the bottom. Don't be offended.
I can't tell what color the smoke is and I can't smell it, so.

The basics:
1)white smoke = burning antifreeze/coolant
2)black smoke = burning excess fuel
3)blue smoke = burning oil

As you can see, we NEED to know what color it is and what it smells like. Just as a precaution, check your coolant level and watch it for a decreasing level.

rolltide0323

This was a cold start.

rolltide0323

I thought it was white to begin with, but it also looks a little blue. hard for me to tell. As far as smell, the exhaust smell is strong. I don't really know the difference in running rich or lean. Sorry

Deakins

It looked a little blue to me; kind of reminds me of a race car deal that's running real fat on start up (would explain the extended cranking as well). I'm not up to speed on the CFI so if it's rich upon start up and then clears out I don't have any ideas on how to fix it. Just my .02

s carter

As many others have pointed out there are a lot of unknowns here
first off you are new to the car, so you may be limited to its past life . how many miles on the car?

so start off with getting a good tune up, before just throwing the parts in inspect what comes out fouled out wet plugs, look into the fuel system or weak wires or ignition.

clogged with carbon, oily plugs valve seals, pushing blue on start up early C4s had a bit of a problem with valve seals. lets face it is a 30 year old car so seals if not already done is a good possibility

pushing white sweet smelling, white crud on plugs, eats coolant, coolant leak inside.

one nice thing about cross fires you can see how the injectors are doing. if they have a fairly nice spray pattern ok but if dribbling like a leaky faucet, injectors need cleaning or even replacing.

rolltide0323

155000 miles currently on the car. The guy who sold it to me didn't know much about the car.

DanZ51

Looks like a classic case of (early C4) valve seals to me. I've done mine a couple of times over the years. Not a deal breaker. If you're handy you can DIY or any locate garage can handle it for a couple hours of shop time.

s carter

definitely not a deal breaker, but with the mileage and age a top end rebuild at least would not be out of the question if funds and time would allow. I have seen cars in the same age and mileage bracket not need but?

or if really motivated a complete and some performance improvements could be done.

or live with the smoke change plugs as needed.

but Fueling, and coolant problems they cant be totally ignored they need looking into

ccrazor

The problem with the delay starting could be a problem with the fuel pump relay not working, and when the motor builds up oil pressure the oil pressure switch contacts operate the fuel pump starting the motor.. Have the wife turn the key to on but don't try to start, you should hear the relay operate for a couple of seconds.. The relay is located just to the left of the brake booster (looking at the booster)..

Tom400CFI

I think that you should check your base timing too; it sounds too retarded, to me.

Cliff Harris

I suggest a throttle body recalibration. It's a fairly complex process, but you can have a lot of problems if the throttle bodies are not set up correctly.

It's relatively common to have leaks at the injectors too, so rebuilding the throttle bodies will probably help.

rolltide0323

Car sat overnight. Started up with no problems this morning.

rolltide0323

Car just left my wife stranded. It wouldn't start at all. It was about 20 mins from her last attempt to crank until i got there. It started on the
2nd try when i got there. Any ideas?

Thanks

Tom400CFI

I have an idea; start a diagnostic process...other wise you'll get a bunch of WAG's.

If it were my car, I'd drive it until the symptom occurs again, then see what is missing; spark or fuel. Nice thing about a Crossfire is you can see the injector spray, so when it won't start, pull the air filter and a plug wire...see which is missing.

I'd also put a timing light on it and check or advance the timing. It sounded really retarded in the video.

Out of synched TB's won't cause it to not start.

rolltide0323

So my wife took her vette to the mechanic to get an inspection and for them to diagnose her issue. They seem to think its the MAP sensor causing the hard start and possibly the smoke as well as the car was running full rich on startup. I will be replacing the sensor tonight and hopefully this will fix her issue.

Thanks to everyone for your suggestions. I would have researched and diagnosed it myself but after misdiagnosing a starting issue with my truck, she wanted to leave it up to the pros

Tom400CFI

You're welcome...but I don't think that you followed a single piece of advice that was given. Seems like a waste of everyone's time, to me. Did you ask the mechanic to check the timing while he has it there?

rolltide0323

I was hoping that this was a simple problem to fix and coming to the forum that lots of people would have had this issue. I will say that if I wasted anyone's time i'm sorry. If I was more confident in diagnosing it I would have jumped right in there and implemented everyone's suggestions. I was hoping it was something fairly simple that I could handle. I was just trying to save my wife some money by coming on here and hopefully resolving her issue.

rolltide0323

I forgot to mentioned to my wife because she is the one who dropped the car off and talked to them.