Thread: Discovery 1 V8 3.9 1999

The only moving part is the gauge so even if the reading is wrong I would assume that the relationship between the readings should be constant
You are seeing one reading which is 25% less than the others
IMO that is a problem

Originally Posted by Phil B

The only moving part is the gauge so even if the reading is wrong I would assume that the relationship between the readings should be constant
You are seeing one reading which is 25% less than the others
IMO that is a problem

Yes agreed , even if gauge is not as accurate as a higher priced one the results should have been within 5%


I now hoping its just the head gaskets, any opinion/experience on the best gasket set to be using ?

Look , the most likely cause of non start is simply that it is flooded.

Take the plugs out and either fit new ones or get a torch and heat up the tips of the old ones if they are serviceable.

When you are trying to start hold your accelerator flat to the floor. Do not pump it. The ECU has a flood clearing mode if your foot is held flat.

Try this for a while, do not do it for just a few seconds.
Good luck.
Regards PhilipA

Yes, the compression is low, but at least not zero. I would expect it to start ok.

I've seen similar readings on a V8 that ran ok, a bit rough but it was drivable.

I would try to solve the non starting before taking heads off.

Get the battery fully charged, can get low with lots of cranking.
Test each plug and lead to see if in fact you have spark on all cylinders. work back from there to distributor and module (if no spark).
New plugs are not expensive.

check the vacuum hose from fuel pressure regulator to rear of plenum, they often split or come off at the plenum end. with the hose connected to fpr. suck on hose try to hold vacuum with your tongue.

It's a painful step by step process.

probably fried module lucas modules dont like heat also check magnetic pickup wire inside dizzy they tend to get a small crack in wire causing the same problem just pray the block has not cracked or the liners have slipped

Originally Posted by Ronski

Yes, the compression is low, but at least not zero. I would expect it to start ok.

I've seen similar readings on a V8 that ran ok, a bit rough but it was drivable.

I would try to solve the non starting before taking heads off.

Get the battery fully charged, can get low with lots of cranking.
Test each plug and lead to see if in fact you have spark on all cylinders. work back from there to distributor and module (if no spark).
New plugs are not expensive.

check the vacuum hose from fuel pressure regulator to rear of plenum, they often split or come off at the plenum end. with the hose connected to fpr. suck on hose try to hold vacuum with your tongue.

It's a painful step by step process.

Ok, well recharged battery, checked all leads and plugs for spark and all good. Checked FPR and put her back together. I also cleaned the MAF and insulated a few bare wires and cleaned all connections on the oem coil pack that was fitted by previous owner as these were very loose. Turned her over with "foot to the floor " as suggested earlier in the post and wooosh she started and purred like a kitten....ok not a kitten growled like a nice old V8 !!!

BUT ! Theres always a BUT she started to slowly heat up, kept an eye on it, Dash temp gauge stayed in the normal range and lower radiator hose is warm..... However the after market temp gauge in the top hose crept up quick to 180 and climbing !! so I shut her down.

I think maybe the thermostat is stuck closed ?? absolutely no leaks anywhere , radiator fans comes on , I will need to do the Head Gaskets due to the compression test but she at least starts and i've cleaned up a few parts.

Thank you

Next step:
Buy a lotto ticket
Sounds like you avoided a larger issue
Amazing what AULRO members can do!

Good to hear, It's beer time.

Strange how a ride on the back of a tilt/tow truck can shake things up

let us know if the thermostat was the cause of overheating.