C4 Injector Removal

Hi All,

I've been tracking this problem down for YEARS and I think I'm finally on to something. PROBLEM: 1988 - starts fine cold and within 5 - 8 mins after shutdown. After that, cars cranks long, starts and idles rough and smells very rich. After she 'clears her throat' she runs fine and strong. No other issues! Changed splugs, wires, rotor, button cleaned MAF wires. Upgraded relays that link to MAF as per production bulletin. Disconnect Cold Start Valve. No resolution and seemed to get worse!

I'm now down to the possibility that my injectors are leaking. I would like to at least pull a couple out to check the o-rings. O-ring kit from dealer is $28. I don't have a service manual (YET!). The task looks daunting. Any advise on the best way to get at these? Any other parts I might need like gaskets, etc.. when doing this job?

TIA!

Save the Wave!

Reply to
88C4RagTop
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BTW, 117,000 kms original kilometers (72, 500 miles) and garaged.

Thanx!

Reply to
88C4RagTop

I had a very similar problem in my 1985. It turned out to be a carbon build up in the combustion chamber. The carbon absorbed gas. When the car cooled a little after being driven, it would release the gas, and flood the engine. The dealership had to work with Chevy to diagnose it. They used some solvent to clean out the engine, and it ran great after that.

Hope this helps...

Reply to
JimH

Interesting, which make one wonder how many more deposits are left in our engines with today's fuels. My C6 has the sootiest looking exhaust pipes I ever seen; looks like they did when the choke stuck in the older cars but gets twice the MPG.

Reply to
Dad

run some Lucas Upper Cylinder Lubricant and Fuel Injector Cleaner

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a couple tanks of gas,be sure and change your gas filter afterwards. g'luck

Reply to
'Key

Hmmm, tend to think you're on to something. I've noticed more combustion roughness when we go through our annual winter-to-summer gasoline changeover -- and it's been worse out West since we had to give up MTBE. Maybe we're getting some Chinese wheat gluten in the gas.

*Hey Dad.* We used to clean out cylinder deposits by 'drizzling' diesel down the carburetor -- do you have a way to 'administer' diesel juice into a 'vette -- or would the internal tamps make this a dumb maneuver?

-- PJ

Reply to
PJ

I'm pretty POd about this gluten business. I haven't lost a pet, but it's driving me nuts trying to keep up with the continual expansions of the recalls.

I'm assuming changing brands of gas for a while to change the detergents in it isn't sufficient.. That these deposits are just to tough/extensive?

AJM '93 Ruby coupe, 6 sp (both tops)

Reply to
CardsFan

Actual we used a product from Ce-Pen-Co that we metered into the carb to burn out the deposits and kill all mosquitoes in a 5 mile radius. There are cleaners in a pressurized cans that screw onto the fitting on the fuel rail to do it now. Of course there is a GM approved version that is 4X the price that they recommend.

Reply to
Dad

Reply to
Greg Vincent

Hmmm.. just spoke to GM and they don't have anything that comes in a can via the schrader valve, just stuff to dump in our tank. Someone else suggested that the O2 sensors can go open loop mode and cause rich buring without flaging a code (ODB1). Could the O2 sensors be causing this as well?

Reply to
C4RagTop

have you even tried to run a good injector cleaner through your tank first ? (suggest the gm cleaner or Lucas Injector cleaner) I would at lease try that before you start replacing the O2 sensors.

Reply to
'Key

Try this out for size (scroll down the page to the paragraph on using an R-12 hose -- you're on your own)

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Here's a product. 3M UNIVERSAL FUEL INJECTOR CLEANER, 10 OZ. AEROSOL (08956)

Note that the can has 100 psi of pressure.

-- PJ

Reply to
PJ

WOW, that's wedding night pressure; just what MacGyver needed back in the late '80's. GM says to boost the pressure up to 70/ 90 PSI to clean/flush the injection system.

Dad

Reply to
Dad

your sig reminds me of this joke I seen on another group.

g'day

Reply to
'Key

Have you any idea how many men would work on that bridge??????

Dad

My greatest fear is there is no such thing as PMS and it is really her personality!

Reply to
Dad

Reply to
Brad

I had exactly the same problem for years with my 1986 convertible. The problem turned out to be the fuel pump. Apparently there was a small crack or something that caused the problem. Once it was replaced entire issue went away.

Reply to
Mike Cenni

On the output of the fuel pump there's what appears to be a snubber -- Chevy calls this a 'pulsator.' Last fuel pump replacement I did, I just replaced the pump and left the old snubber in place. (IIRC the price of a new one seemed high.)

Wonder what the life of a snubber is and what the symptoms are when it quits 'snubbing?'

Reply to
PJ

Wow, remember the days when you could just pour water slowly down the carb and clean all the carbon out?

Too bad you can't do that today.

(lot of stuff snipped)

Reply to
Tom in Missouri

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