I have a 1998 Chevy 1500 p/u with the 5.0 litre engine. It became very hard to start, especially when cold(sitting for long periods of time). I took it to a mechanic and was told it was the timing chain. Spent $1200 letting them replace the timing chain and it still wont start after sitting overnight. Replaced the spider injection system myself and thought I had the issue solved, but it still ran rough once cranked. I broke the pcv valve hose while installing the injection system. Replace the assembly with a new one and now it runs great once you get it cranked. However, getting it cranked is next to impossible. Turns over and fires like it wants to start, but just won’t quite start. The mechanic that replaced the timing chain says there is a “wetting” issue, whatever that means. Once the truck has been cranked it runs great! No misses, no hesitations and fires back up with just a bump of the key. I am at a loss for what could be wrong!
I think your mechanic is telling you the head gasket is bad. AFAIK that’s what “wetting” generally means. Coolant is getting into the cylinders and fouling the plugs.
He specifically mentioned the “wetting” issue being fuel related. They were able to start the truck by removing the spark plugs and putting a small amount of transmission fluid into each cylinder. It really doesn’t make sense to me.
Okay, that actually does make sense. The plugs are being fouled with fuel. The dab of transmission fluid is an old trick for cleaning carbon deposits. You need to figure out what’s causing the problem and fix the root cause. My guess is a faulty oxygen sensor but it could be something else.
Believe me…definitely trying to get to the root cause. Very frustrating! So, a faulty O2 sensor could cause fuel to leak down into the cylinders?
No, I don’t think there’s a leak at all. I think a faulty oxygen sensor is tricking the fuel injection pump into supplying too much fuel and the extra is fouling the plugs.
I gotcha. That is a logical explanation. Certainly worth exploring.
Best of luck. Happy motoring.