Bringing a 740 back to life

[Laird Scooby]

Originally Posted by Challo

Tried the tap and slap a few times this morning but no luck on getting her started. I’ll order the ATF and give that a go and see if we have any luck.

Just a thought, but as I changed the pump and filter under the car, could I have done anything wrong here? You can hear the pump now, and all the pipes and screws put back together properly with no leaks.

As long as you replaced like for like and got the correct polarity on the electrical connections you should be ok on that. How much fuel is actually in the tank?

[Challo]

Originally Posted by Laird Scooby

As long as you replaced like for like and got the correct polarity on the electrical connections you should be ok on that. How much fuel is actually in the tank?

It’s low according to the needle, right at empty. I did put a 5l Jerry can in the car yesterday. But I’ll add another 5l in the week

[Laird Scooby]

If the in-tank pump isn't working that might not be helping. Really needs to be above ~1/4 so the main pump has a chance of pulling some fuel through, often with a dodgy in-tank pump, as long as the level is above 1/4 the main pump will manage to pump fuel.

[Challo]

Originally Posted by Laird Scooby

If the in-tank pump isn't working that might not be helping. Really needs to be above ~1/4 so the main pump has a chance of pulling some fuel through, often with a dodgy in-tank pump, as long as the level is above 1/4 the main pump will manage to pump fuel.

Put enough petrol in the car to get the tank over 1/2, tried cranking again but again no start. I'll have a bit more time at the weekend to take off the fuel line at the rail and see if its coming through.

I'll also get underneath and check the pump and filter again to make sure they are all connected correctly. I think they only go one way due to the size of the bolts either side of the fuel filter but will confirm.

As a quick test, I might reconnect the old fuel pump and see if the new one is faulty? Changing the relay defiantly made the pump switch on so the new one might have a fault. Worth checking I suppose.

[Laird Scooby]

Has to be worth a go - out of curiosity, when you replaced the main pump was fuel flowing out of the inlet pipe while you were swapping them over?

[Challo]

Originally Posted by Laird Scooby

Has to be worth a go - out of curiosity, when you replaced the main pump was fuel flowing out of the inlet pipe while you were swapping them over?

Yes. When I first changed the fuel pump / filter there was some fuel in the pipe and filters that needed to be drained out. When I had to take it apart again due to missing the brass crusher washers again fuel was coming out the pipe and I had to drain both the filter and pump due to them having fuel in them.

[Challo]

Finally got time today and got the car started. Changed the fuel pump back to the original one and it fired up. Need to contact PFS on the faulty pump.

Once started it’s really lump, and when rev the you can hear a belt screeching. The timing belt has been changed, but unclear on any of the others.

With no revs it barely ticks over, checked the fresh plugs and they are black. I have added a photo. Also there appears to be some oil deposits out of the exhaust. Attached photos

I did check the spark plugs I bought and the gapping is all wrong. They are about .4 rather than .7

[Laird Scooby]

Originally Posted by Challo

Finally got time today and got the car started. Changed the fuel pump back to the original one and it fired up. Need to contact PFS on the faulty pump.

Once started it’s really lump, and when rev the you can hear a belt screeching. The timing belt has been changed, but unclear on any of the others.

With no revs it barely ticks over, checked the fresh plugs and they are black. I have added a photo. Also there appears to be some oil deposits out of the exhaust. Attached photos

I did check the spark plugs I bought and the gapping is all wrong. They are about .4 rather than .7

First question - are you reading your feeler guages correctly? If you've got imperial feelrs, 0.04" is in fact 1mm so way too large, double check your feelers as most plugs (NGK i know are set at 0.9mm = 0.036") are set to ~1mm give or take at the factory.

That screeching belt is likely to be the alternator drive belt(s), probably slipping because it's too loose or the pulleys have gained some surface rust which is preventing good friction.

Wait until it's completely cold again and try restarting, the AAV (Auxiliary Air valve) should open by then but it closes with ignition on. Chances are if the "new" pump wasn't delivering enough pressure the mixture would have been too weak to fire so any fuel it did inject would remain unburned. Your PCV system may also be blocked which would make it richer and slower.

No photos on your post, given the fact it has had unburned fuel through the exhaust i'd expect the tailpipe to look oily.

Suggest you clean the plugs, regap them to 0.65mm or 0.025", depending on your feeler guages (post a photo of them if unsure), check your PCV breather system for any and all blockages and clean it if necessary (almost certainly will be and no harm in doing it even if you're not sure), check your air filter for cleanliness and maybe even disconnect the concertina'd aluminium heat tube from the exhaust manifold to air box at the air box end.

Then try it, run it up to temperature and see what it's doing then.

[Challo]

Originally Posted by Laird Scooby

First question - are you reading your feeler guages correctly? If you've got imperial feelrs, 0.04" is in fact 1mm so way too large, double check your feelers as most plugs (NGK i know are set at 0.9mm = 0.036") are set to ~1mm give or take at the factory.

That screeching belt is likely to be the alternator drive belt(s), probably slipping because it's too loose or the pulleys have gained some surface rust which is preventing good friction.

Wait until it's completely cold again and try restarting, the AAV (Auxiliary Air valve) should open by then but it closes with ignition on. Chances are if the "new" pump wasn't delivering enough pressure the mixture would have been too weak to fire so any fuel it did inject would remain unburned. Your PCV system may also be blocked which would make it richer and slower.

No photos on your post, given the fact it has had unburned fuel through the exhaust i'd expect the tailpipe to look oily.

Suggest you clean the plugs, regap them to 0.65mm or 0.025", depending on your feeler guages (post a photo of them if unsure), check your PCV breather system for any and all blockages and clean it if necessary (almost certainly will be and no harm in doing it even if you're not sure), check your air filter for cleanliness and maybe even disconnect the concertina'd aluminium heat tube from the exhaust manifold to air box at the air box end.

Then try it, run it up to temperature and see what it's doing then.

Feel a bit of a tit this morning. Checked and adjusted all the spark plugs to the correct gap and gave them a clean. Tightened up the alternator belt and started her up and still lumpy. Couldnt really understand why and then realised I had cleaned the MAF previously and forgot to plug the sensor back in. Reconnected and it started ticking over nicely. No longer lumpy, and even managed a trip to the end of our close and back and ran well.

I did take a look at the PCV box, and it looks pretty grim. The pipe look past their best, and also it appears there has been some bodges to fix holes on the connections to other pipes. Lots of sticky black stuff. Best bet is to order a new box and the replacement pipes.

I do need to degrease the engine as well though. Lots of old oil all around the block from previous leaks, and no doubt from a blocked PCV. Will clean it up and see what other leaks I can find.

I have a attached a photo from underneather the car of what looks like the sump? Its covered in oil so I suspect the pipe or connector has failed? Does anyone know what this is called?

Plan is to book it in for an MOT and and see how it performs. Will give me an idea on whats next to fix.

[Laird Scooby]

Originally Posted by Challo

Feel a bit of a tit this morning. Checked and adjusted all the spark plugs to the correct gap and gave them a clean. Tightened up the alternator belt and started her up and still lumpy. Couldnt really understand why and then realised I had cleaned the MAF previously and forgot to plug the sensor back in. Reconnected and it started ticking over nicely. No longer lumpy, and even managed a trip to the end of our close and back and ran well.

I did take a look at the PCV box, and it looks pretty grim. The pipe look past their best, and also it appears there has been some bodges to fix holes on the connections to other pipes. Lots of sticky black stuff. Best bet is to order a new box and the replacement pipes.

I do need to degrease the engine as well though. Lots of old oil all around the block from previous leaks, and no doubt from a blocked PCV. Will clean it up and see what other leaks I can find.

I have a attached a photo from underneather the car of what looks like the sump? Its covered in oil so I suspect the pipe or connector has failed? Does anyone know what this is called?

Plan is to book it in for an MOT and and see how it performs. Will give me an idea on whats next to fix.

No pics there of the PCV system as far as i can see. I did notice a split on one of the T's on the MAF to throttle body, that will cause rough running. I also thought yours was the K-Jetronic GLE being a 1990 and not the B230F but just reread and see it is an LH2.4 Jetronic.

Pull fuse #1 for 30 seconds or so then refit before you next start it - that will clear any historic faults that might have put it into Limp Mode.

***EDIT*** Have a read of this, gives you more of an idea on the PCV system on yours :

https://blog.fcpeuro.com/the-rwd-vol...plete-overview