mickyb5191

Hey thanks for looking at my thread I'm rather desperate for help.

I have a Sierra 2.8v6 turbo technics. Basically It had a temperamental starting problem that came back to the pink fuel pump relay changed that and it started and ran fine then when I turned it off today and tried to start it, and nothing then came back to it a few hours later this evening it started and ran fine for less than 5 minutes then as I backed it off the drive it cut out. And wouldn't start I have checked the spark and it's fine I checked the fuel it's got fuel up the spark plugs are ok the dizzy is fairly new and the leads are new I've checked all the obvious and can't seem too find the problem. I had the car running for over two hours after sorting the fuel pump relay out this morning and took it for a short drive out now it's jus doesn't want to go. If anyone has any knowledge they would like to share it would be most appreciated many thanks.

155lee

iTrader: (10)

Cold start injector flooding it?
Had that prob on an old 2.8 I had.sure it's on the top of the plenum,try disconnecting it.

mickyb5191

Thanks I'll give it a shot.

XR2

Fuel filter is new?

Won't start when it's warm?

Check the spark plugs when it refuses to start, I bet they're dry.

mickyb5191

Hi xr2 after cranking it over last night and it running for less than 5mins, I took a plug out and checked for spark but the plug was soaked in fuel. Actually feel like getting the hammer out now haha

XR2

Hot start problems are usually caused by two problems:

1. worn injectors. The mechanical K-Jetronic injectors suffer from wear, when they're older than 100.000 miles then it's time to replace them. They start dripping after the engine is turned off, this resulting in reducing fuel pressure between injector and metering head. The fuel inside the lines will get warmer because of the warm engine and because of the lower pressure the fuel will begin to vaporize. These "steam bubbles" inside the lines will be compressed when you start to turn the engine. Then the pressure-operated injectors won't get enough pressure and won't open.
2. Broken pressure valve on top of the fuel pump. This prevents fuel from being pushed back into the tank through the pump when the fuel is getting warmer and starts to expand when you turn off the engine. Especially combined with problem 1 this will cause hot start issues.

And your plugs might be wet because of the dripping valves, but the engine won't get enough fuel to fire up so the sparks will stay wet...

XR2

Oh one more thing I forgot:

I had problems with the loom connector on the distributor on my (CVH MFI) engine. One of the pins inside the connector was loose, this resulting in not bringing a signal to the rpm relais, resulting in a not running fuel pump and not working ignition when cranking.