Difficulty cold starting V8
#1
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Location: Scotland, Ayrshire coast
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Year: 1999
Model: Grand Cherokee
Engine: 4.7 V8
Difficulty cold starting V8
My 99 V8 takes a bit of winding before it will start on the recent cold mornings. I fitted a brand new Bosch battery a couple of weeks ago, and had new spark plugs fitted last week.
It seems to be an engine dampness problem as it fires up after I spray the visible electrical terminals with damp start / WD40 type spray
Is this a common problem, is there a fix ?.
It seems to be an engine dampness problem as it fires up after I spray the visible electrical terminals with damp start / WD40 type spray
Is this a common problem, is there a fix ?.
#2
This is usually caused by a leaking fuel pump check valve or fuel injectors.
The fuel pump contains a check valve so the fuel doesn't drain back after you shut the engine off. When this valve leaks, you will have a long crank time before it starts. Usually if it's the fuel pump check valve it will have a long crank time after sitting overnight.
If it isn't that, then it may be your coolant temp sensor going bad..
http://autorepair.about.com/library/faqs/bl226i.htm
The fuel pump contains a check valve so the fuel doesn't drain back after you shut the engine off. When this valve leaks, you will have a long crank time before it starts. Usually if it's the fuel pump check valve it will have a long crank time after sitting overnight.
If it isn't that, then it may be your coolant temp sensor going bad..
http://autorepair.about.com/library/faqs/bl226i.htm
#3
Old fart with a wrench
The dampness on the Scotish coast is legendary! It's like living in a swamp! I think you may have to pull and clean ALL your electrical plugs and connectors and apply dielectric grease. DO NOT grease the 02 sensor plug because the signal levels are so low, grease might interfere. I don't know if your overseas model still has spark plug wires or coil packs, but if it has wires, replace them.
You can install an in-line check valve for the fuel system before you drop the tank and replace the pump. If you have an external fuel filter with three hoses, the check valve is in the filter. Your 99 is the change-over year from the ZJ to the WJ and lots of things are different, as well as being an overseas model.
You can install an in-line check valve for the fuel system before you drop the tank and replace the pump. If you have an external fuel filter with three hoses, the check valve is in the filter. Your 99 is the change-over year from the ZJ to the WJ and lots of things are different, as well as being an overseas model.
#4
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Year: 1999
Model: Grand Cherokee
Engine: 4.7 V8
Cheers guys the problem seems to be the terrible dampness we have here as it starts okay on dry mornings, a spray of damp start or WD40 type spray helps. I've never heard of the grease but I will remove the contacts and spray them with electric contact cleaner at the weekend.
The coils over the plugs are another possible source, I've owned several Jaguars fitted with the dammed things and they always caused problems
The coils over the plugs are another possible source, I've owned several Jaguars fitted with the dammed things and they always caused problems
#5
Old fart with a wrench
The grease will help especialy where the coils fit over the plugs. Your high voltage may be shorting over.
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