skullandbones

This is a new issue I have after the car has been sitting for 24 to 48 hours. When I first start it, it runs extremely rough like it is missing on a couple of cylinders. It also has a smell like it is flooded. I am not depressing the accelerator during startup. I have always heard some weird sounds from the fuel pump but this condition is new with the fuel pump still making the sounds after shutting down.

I'm thinking this has to be a fuel issue like a stuck injector (gummed up). If not that could it be a fuel regulator or fuel pump? I haven't tuned the car up since I got it. I suppose the injectors could be in need of some TLC or replacement. My first thought is to try some injector cleaner. Is there a favorite you use?

Thanks,

WEK.

aklim

Could be the fuel draining back to the tank or inagination, hard to say. A gauge will tell you for sure what is going on. After shutdown, it should hold pressure for a while. Without power, pump doesn't run so that rules that out.

You might have Multecs which should be replaced with reman Bosch 3 from FIC since it is cheaper. Not worth it to send them to him since it is almost as much to clean as it is to get a reman set and less down time ASSUMING it isn't Multecs. Pick any injector cleaner. You will feel a difference because you spent money, aka Placebo effect. Look at your injectors. I have never used that snake oil. It's purpose is to drag in a sucker since it is cheap and hope he convinces himself that it is doing wonders for cheap.



Also, next thing I would do while the intake is off for injector change is to clean the TB. Take it off and do the coolant bypass for easier access. Remove the top plate, take IAC off and take the IAC housing off. Clean housing and TB with brake cleaner and all passages. Gently spray cleaner on the pintle of the IAC and wipe down. Reassemble with new gaskets.

JrRifleCoach

You may also want to check for a ruptured FPR diaphragm.
Pull the vacuum line from the FPR and smell it for fuel.
If yes, replace the diaphragm.

aklim

Good point if I am there, I'd prefer to replace it because it is so old.

skullandbones

I will take those recommendations in order of difficulty. Definitely the regulator first. That's an easy one.

Do you think a bench test to observe spray pattern would be worth the trouble? I've seen it done on u tube and on Wheeler Dealer. That mechanic is either a real master or a damn good actor playing a mechanic. BTW: I have had mixed results with cleaning the TB and the IAC but I chased the problem on my Cobra for a while until I finally cleaned the IAC and it ran perfectly after that. I guess it's just one of those things where you have to do the work 'til you hit the right one.

Thanks for your advice,

WEK.

aklim

I don't have and haven't had stock for a while so IDK. AFAIK, to get to the regulator you have to take the TB and upper intake manifold off. If I am there, I'd do the bypass, clean the TB and injectors

Again, depending on what you have. Multecs don't play nice with ethanol and most fuel has ethanol unless it is in a marina or one of the few and expensive places, at least around here. So sooner or later, the Multec will fail. For what FIC charges for a reman, it is about the same as cleaning a set of Bosch 3 injectors. In my case, I have 42pph so it might be easier to clean them. Homemade injector benches are cute. But what I want to see is the volume and spray pattern. With a proper bench, you can see all 8 at the same time and check comparative pattern under calibrated pressure and volume. The homemade ones are nowhere as precise.

skullandbones

Oh well. That sucks!! I will have to wait til this weather moderates a little before taking it apart. I also had some rodent damage to an injector wire so I will have to change that pig tail and resolder while I have it apart. Unfortunately, I got used to working on Chevy hot rods which are lots simpler to work on than modern cars. Time to get my hands dirty!

WEK.

skullandbones

Just to see how much this little project is going to cost I checked with Ecklers for prices. I couldn't believe a diaphragm kit of 8 o rings and a spring with rubber boot cost $188 on sale. The intake gasket kit sounded, at least, in the ball park but not the repair kit. I asked the guy if that was a misprint. He gave me a rather smug answer, "no sir, that's the correct price". I will be shopping elsewhere for that item. Honestly, I think I could buy a billet after market regulator cheaper than repairing the OEM one.

WEK.

aklim

Have you given FIC a call?

mark970

you guys are using a lot of words i dont know (i'm not a mechanic)

but did somebody mention a fuel pressure regulator? because the symptoms sound EXACTLY like both GM vehicles (99 tahoe and 96 sunfire) i had that needed that replaced. they were fairly easy to replace (on those 2 vehicles anyways) and problem was solved. rough start after sitting overnight, but would start just fine with the engine warmed up

JrRifleCoach

^^ You're right!

There are lots of cross over part numbers for Camaros as well.

Noobs need to know that Ecklers HAS THE HIGHEST prices, and are the last resort for parts.
Goto the local parts stores or RockAuto before considering some of the specialty houses.

59 bucks......http://www.rockauto.com/en/catalog/c...regulator,6124





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skullandbones

I must apologize for ranting about the price. It just seems so obscene to as 4 times what it is worth and then have the nerve to call it on sale. I'm done. I checked on Amazon which is not always the lowest price but we have Prime so I can get stuff in 2 days or less if in a hurry. I found a new billet regulator and intake gaskets (kit) for $80 shipped.

Curiously, I went out to the Corvette garage and the thing started perfectly after sitting for 5 days. It ran well while I was out driving in our summer heat (today 114). The only thing I can guess is that this happens after it's been sitting for a few hours to 24 hrs. After that the excess gas must be evaporating so there isn't a problem. I will continue monitoring this. Can't really tackle the problem now as the weather is just no cooperating. It will be the end of August before I can do it comfortably. But it is running well right now. Last night I went to the FSM and could not find a reference to the regulator but I did see what looked like the image of it on the fuel rail in the rear and between the two fuel rails. I may have missed it in one of the diagrams but I looked quite a while. Aklim is right, that sucker is buried under the intake. I don't even know if I can check the vacuum line. I will see about that in a little while. Thanks for the heads up on the right injectors to replace.

WEK.

JrRifleCoach

Sure you can check the vacuum line. Just trace it from the FPR forward to the other end.

Duhhhh.

aklim

Unless you know the vendor and what spec they manufacture it to, don't be so sure that a cheap part is just lower priced. I've been bit by that one before. There is ALWAYS a reason it is sold for less.

Yes you can. There is a line that leads to the manifold. That is what you need to check. It is a rubber line so....

skullandbones

Our hot spell has begun to moderate. It was 119, 121, 118, 118, 116, 115 last week. So 110 doesn't seem so bad.

I mentioned that this has been intermittent. Well, now I'm wondering if it is not the engine at all. I've driven it three times and it has run normally all three times. I was down to about a quarter of a tank or less so I got some gas not long ago. If this turns out to be bad gas, I will feel stupid for bringing this up. I have let it sit for a while now so I will try driving it again Friday to see if I get the same symptoms, again. I'm still researching the different sites for the suspect parts. If nothing else it will give me a little more knowledge on parts for this model. I'll report back after my Friday drive.

WEK.