Bringing a 740 back to life

[Challo]

Originally Posted by Laird Scooby

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.

Yep mine is the B230F, I had pulled the fuse previously but will do it again. Yes sorry no photos of the PCV, I defo need to replace it. It was more the pipes from the MAF to the throttle body. I’ll order those as well

Any idea on the last picture from underneath the car? Is that the sump? Been trying to find it in the Haynes manual and it’s not clear.

[Laird Scooby]

Originally Posted by Challo

Yep mine is the B230F, I had pulled the fuse previously but will do it again. Yes sorry no photos of the PCV, I defo need to replace it. It was more the pipes from the MAF to the throttle body. I’ll order those as well

Any idea on the last picture from underneath the car? Is that the sump? Been trying to find it in the Haynes manual and it’s not clear.

That's the gearbox sump but the oil is coming from the top rear of the engine from the look of things, chances are it's the seals in the distributor but could equally be from the rocker cover gasket, especially if the breathers are blocked.

[Challo]

Originally Posted by Laird Scooby

That's the gearbox sump but the oil is coming from the top rear of the engine from the look of things, chances are it's the seals in the distributor but could equally be from the rocker cover gasket, especially if the breathers are blocked.

Thanks. The rocker cover has been changed a few years apparently, but like you say the PVC is probably blocked and causing a right mess.

I’ll degrease everything and see where I stand when it comes to leaks .

[Challo]

New air intake hoses arrived yesterday from Ashley Classic, so got them changed this lunchtime. Still runs rich, so I do need to get that PCV box off and cleaned out. The top hose internals looked caked in oil, and there was oil sat in the air intake hose.

Got it booked in for an MOT on the weekend, not expecting it to pass but thought it would allow me to see what else needs, to get it through.

On checking all the lights I noticed the left rear indicator bulb wasn't working when indicating. Checked the bulb and it all looked good, reconnected it and while the hazards come on with the button pressed, when I use the indicator (left / right) nothing happens.

Ran out of time at lunch, so will check again after work and see if a fuse has gone.

The wonders of a 30year old car :-)

[Laird Scooby]

Originally Posted by Challo

New air intake hoses arrived yesterday from Ashley Classic, so got them changed this lunchtime. Still runs rich, so I do need to get that PCV box off and cleaned out. The top hose internals looked caked in air, and there was oil sat in the air intake hose.

Got it booked in for an MOT on the weekend, not expecting it to pass but thought it would allow me to see what else needs, to get it through.

On checking all the lights I noticed the left rear indicator bulb wasn't working when indicating. Checked the bulb and it all looked good, reconnected it and while the hazards come on with the button pressed, when I use the indicator (left / right) nothing happens.

Ran out of time at lunch, so will check again after work and see if a fuse has gone.

The wonders of a 30year old car :-)

Turn the hazards on/off several times in sharp jerky movements Chris - often if they're not used for a period of time and then used for testing (or sitting by the side of the road) the contacts don't find the indicator position again inside the switch.

[Challo]

Originally Posted by Challo

New air intake hoses arrived yesterday from Ashley Classic, so got them changed this lunchtime. Still runs rich, so I do need to get that PCV box off and cleaned out. The top hose internals looked caked in oil, and there was oil sat in the air intake hose.

Got it booked in for an MOT on the weekend, not expecting it to pass but thought it would allow me to see what else needs, to get it through.

On checking all the lights I noticed the left rear indicator bulb wasn't working when indicating. Checked the bulb and it all looked good, reconnected it and while the hazards come on with the button pressed, when I use the indicator (left / right) nothing happens.

Ran out of time at lunch, so will check again after work and see if a fuse has gone.

The wonders of a 30year old car :-)

PCV changed today, it was blocked, and all the other pipes where thick with sludge. Gave them a clean out and replaced what I could with new parts.

Also changed the oil which was a nightmare. No idea when it was last changed, but the oil was black and the filter was stuck on. Took me about 40mins to eventually get it replaced. Fresh oil in, spark plugs cleaned and fuse 1 removed to reset everything.

Started the car and it still seems to be running rich, and splatter of oil coming out of the tailpipe. I suspect there is still some crap in the system and will improve with a good run out. Got the mot next weekend so will take the long route there and get the car properly up to temperature.

I did notice a slight blow in the exhaust. Tightened up the bolts on the clamp, but I think it needs re-sealing again.

[Laird Scooby]

Sounds like you've had a productive day Chris - before taking it for the MoT give the breather system another good clean out with carb cleaner, also don't forget the small bore pipe stubs on the inlet manifold that provide vacuum to the PCV system, these have a habit of clogging easily.

Also if it's been neglected for some time experience has proved that they almost always need cleaning again at least once (sometimes 2 or 3 times) each a month apart.

The splatter of oil from the tailpipe was probably just soggy soot, oil shouldn't be getting near the exhaust!

Try tightening the exhaust after a run while the exhaust is still hot - firstly it's more flexible because it's warmer, second the gaps will have increased due to expansion of the clamps and/or bolts due to heat and thirdly, usually the nuts/bolts etc are easier to turn once hot so you can tighten them more tightly.

Once cool again they will "force themselves" into a gas-tight seal and stay there - usually!

[Challo]

MOT today and she failed :-( Looking at the list of things it could have been worse, but at least I know what I need to get her back on the road.

1. Battery insecure - It never came with a clamp to hold the battery, so will need to look at ways to get it secured.

2. Binding brakes - I need to take off the front wheels and look at the calipers to see how bad they are. Hopefully they just need a clean rather than full replacement? It also notes the disks are slight pitted so perhaps a full brake overhaul?

3. Steering Rack Gaiter damaged - I'll look at getting a new boot, and inner tie rods changed as there is some play.

4. Rust - There is a small hole into the engine bay on the left hand side. I took off the wheel arches to clean behind and didn't put back. Would have hidden the hole :-)

5. Exhaust readings - On start up the idle was fine, but after a drive when it goes into park the idle sits about 1500 rpm. I need to give the hoses another clean off the air intake and perhaps clean the throttle body?

I know its a big list, but all easily replaced. The bulbs I didn't check before but have spares.

The test did comment that underneath the car it was very clean, not area's of concern and looked in good nick for a 30year old car.

Going to start looking online for some part prices.

Forgot to add. The tester did mention there looked to be a slight leak from the rack, but wasn't clear. Suggested when I take the gaiter off to check.

Also on the drive to the test centre the speedo doesn't work :-( The rev counter and clock is fine, but the speedo failed to register.

[TonyS9]

On the 940 if you have no speed signal getting to the fuel ECU it will raise the idle rpm to over 1500 after you use full power. I have no idea if this applies to your car, but I'd definately look at the pickup wiring going into the rear axle to start with.

[Laird Scooby]

Fixed the rotation for you Chris.

What were the emissions? Being a 1990 car it can go up to 3.5%CO and 1200ppm HC so anything below that should have passed.

On the air filter, there's likely a convoluted aluminium hose running all the way to the exhaust manifold, if it's still there and intact, disconnect it from the air filter. THere's meant to be a thermostatic flap valve inside the air filter intake but the 'stat fails so it pulls hot air from the exhaust enriching the mixture as a result. Also get the engine idling, remove the vacuum hose from the FPR (Fuel Pressure Regulator) and put your thumb over the open hose. Observe the stub on the FPR to see if any fuel comes out, if it does you need a new FPR and that's the most likely cause of rich running, if it is indeed running rich - many of the 90-92 740s have emissions exemptions, worth asking the tester to check as it's more common than you might think!

It appears the 1992 740 with the B230F had higher limits than the usual for that year, nothing before that though so safe to assume that even with the cat on yours, it should be 3.5%CO and 1200ppm HC :



https://assets.publishing.service.go.../section-1.pdf

Link to the origin .gov document, you want Pg162 for yours.

Bulbs - remove then and check to make sure the filament is ok, if so rub the end contacts on your jeans to clean the, the side of the bulbs the same, clean the bulbholders and refit (note the staggered pins on the stop/tail bulbs, make sure you get it in the right way which should be easy, very hard if the wrong way!).

A small amount of welding and have a word with Luke aka 360beast about a battery clamp and bolt.

Front brakes, undo the bolts on the guide pins assuming you have the single piston sliding caliper and remove the guide pins, clean them with a wire brush and use silicone or copper grase to lube them. While they're out, remove each pad one at a time, clean the edges of the pads and where they sit in the caliper, again some copper grease on the edges where they contact the calipers (don't get any on the friction material! ) and that will probably fix them.

Clean the throttle body, AICV and PCV system again, make sure there are no air leaks into the inlet, a silly question, you haven't touched the hard to reach throttle stop screw have you?

Rack gaiter, good call, fit a new one and have done for now. Meanwhile investigate what other problems are present on the rack and maybe consider a reconditioned rack, probably cheaper and easier in the long run that faffing about renewing parts that might be redundant if the rest of the rack is unseviceable.