Your Thoughts Welcome ..... Engine Revs Playing-up

[Laird Scooby]

Originally Posted by bob12

Quick additional question to the experts (searched the internet but not much luck so far) ....

...... what's the size (internal diameter) of the small length of flexi hose between the end of the Bosch LH2.4 fuel rail between the FPR and the length of metal pipe on the return fuel line as highlighted in the attached pic?

It will be the same size as that on the other end which disappears back to the fuel tank.

I have a spare FPR (somewhere) and I am thinking of trialing/replacing the original FPR if I suspect a 'petrol' problem with it but, I will have to destroy the existing 'flexi' which over 33 years has set hard like concrete!

It is larger than the hose betwen the FPR and the manifold. Rubber or Silicone?

Cheers, Bob

That's 8mm bore fuel hose Bob, you'll need SAE 30R9 spec hose to cope with the moonshine aka ethanol :

https://www.ebay.co.uk/itm/265291462525

You should be able to get some locally in a motor factors and i'd suggest buying a fair bit more than you think you need.

[bob12]

That's an amazing link Dave!

RacingXS are literally 5 mins away from me on the road from Light_water (Oh, the Forum doesn't like the place name words Light and water joined!) to Windlesham!

I will give them a call tomorow to see if I can pop round and collect!

Cheers, Bob

[Laird Scooby]

Originally Posted by bob12

That's an amazing link Dave!

RacingXS are literally 5 mins away from me on the road from Light_water (Oh, the Forum doesn't like the place name words Light and water joined!) to Windlesham!

I will give them a call tomorow to see if I can pop round and collect!

Cheers, Bob

The forums profanity filter is back on hyperdrive again i see! I'd never thought about Light-water containg a 4-letter profanity although i did spot the one in Skunthorpe many moons ago having met someone who came from there. As he'd moved out of that place i thought it should be renamed Shorpe but nobody else agreed!

There used to be a series on ITV called Night-watch (all one word) and i told a friend when that presenter left thy'd have to rename it Nighch because the twit (oops, my typing is terrible! ) had left. That was 15-20 years ago now.

On a more serious note, glad the link proved useful Bob! Worth double-checking the hose clips too, especially those sprung ones (i forget the proper name for them now) as they go weak with age (just like the road springs on cars) and don't grip the hoses properly anymore.

It's a known thing in Honda circles as one of those is used on the radiator bottom hose connection of some models - you can imagine the results of a weak clip there!

[bob12]

Originally Posted by Laird Scooby

The forums profanity filter is back on hyperdrive again i see! I'd never thought about Light-water containg a 4-letter profanity although i did spot the one in Skunthorpe many moons ago having met someone who came from there. As he'd moved out of that place i thought it should be renamed Shorpe but nobody else agreed!

..........

On a more serious note, glad the link proved useful Bob! Worth double-checking the hose clips too, especially those sprung ones (i forget the proper name for them now) as they go weak with age (just like the road springs on cars) and don't grip the hoses properly anymore.

........

I am off now to bed now but will take a cooling 'shower' before!!

Bob

[bob12]

Good'ish immediate response today from RacingXS to my eBay message.

No local collection for small quantity (1m + 4 clips) unless special need when maybe could drop off. Not unsurprising looking at eBay dispatch location and that of supplier.

As next week fine for me I ordered today and await delivery mid-next week.

That will give me a little more time to clean up the TB fixing area of the manifold .... once its stopped raining. Then refit the TB etc.

For the time being I have given up trying to get the PCV oil separator out from the maze of pipework and wiring etc under the inlet manifold and cold start valve. Clearly, on original assembly it was fitted before the maze of associated 'stuff' underneath the intake manifold!

Everything was disconnected but you can't remove the top return pipe to the flame trap and intake manifold from the oil separator to get enough room to lift the separator up far enough to exctract it from the lower engine block and clear the intake manifold!

Depending on results on starting (hopefully!) when leads/dissy/plugs etc on other side of the engine also replace both under bonnet flexi-sections of the return fuel line will be renewed if I decide to swap out the existing fpv for a spare.

Bob

[bob12]

That's looking a little bit better over that side!!

Still not convinced about the FPR as the old hose sniffed a little of high octane when replaced, especially as there was a small puddle of same in the immediate TB intake manifold low section when the TB originally stripped out but, time will tell. Before that await delivery of new injection return flexi hose.

Trouble is now got to move on to the other side removing and replacing that stupidly short on space camshaft dissy cap/rotor and then replacing the plug leads not forgetting the correct cap sequence 2.1.3.4 (cap right to left view from engine front No1).

Me also thinks the coil which is looking a bit 'oily weepy leaky' could do with an in-stock used replacement. Not to mention replacing the servo vacuum hose which could really do with a refresh after all these years!

It's never ending at the moment ... hey,ho!!
.
Bob

[Laird Scooby]

Originally Posted by bob12

That's looking a little bit better over that side!!

Still not convinced about the FPR as the old hose sniffed a little of high octane when replaced, especially as there was a small puddle of same in the immediate TB intake manifold low section when the TB originally stripped out but, time will tell. Before that await delivery of new injection return flexi hose.

Trouble is now got to move on to the other side removing and replacing that stupidly short on space camshaft dissy cap/rotor and then replacing the plug leads not forgetting the correct cap sequence 2.1.3.4 (cap right to left view from engine front No1).

Me also thinks the coil which is looking a bit 'oily weepy leaky' could do with an in-stock used replacement. Not to mention replacing the servo vacuum hose which could really do with a refresh after all these years!

It's never ending at the moment ... hey,ho!!
.
Bob

I'd give the coil a spray with brake cleaner or similar, wipe it clean/dry and keep an eye on it Bob - it's very unusual for the OE Bosch coils to fail or even leak so i'd guess it's accumulated dirt, dust, moisture etc over the past (nearly) 4 decades.

The acid test of the FPR is to unplug the vac hose from it while idling and plug the vac hose with your thumb (or an M5 bolt) and observe the vac stub on the FPR - if fuel comes out, it's dead.

[bob12]

Thanks Dave. Dissy cap now finally off. It took longer bent double over the back of the engine to work out which tool/s to use and angle of attack than to get the bugger off!! It has lasted 20 years since I last replaced it and the rotor. I won't put a photo up for fear of ridicule!

Bob

[bob12]

Seem to be getting there ..... slowly.

As said TB completely cleaned and now new dissy cap/rotor fitted (a pain in the backside!) together with plug leads fitted this pm. Coil terminals cleaned up.

Test drive much much better but revs now idleing about 1,100 rpm rather than 8/900 rpm. Suspect car running a bit rich.

Immediately after return with engine stopped pulled the pipe off the FPR (didn't want to do it with engine running for fear of petrol spray if faulty) dry and then, ooooh .... a small amount to petrol appeared at the connector on the regulator.

Not good!! Clearly the diaphram has gone and that's propbably why there was a small puddle of petrol at the lowest point on the manifold at TB connection when I took that off as the petrol was immediately below the FPR vacuum connection on the manifold.

Have now received a metre of new injection pipe and clips for the return line per Dave's recommendation so the next job is to swap out the FCR from the breaker and see if that's OK. If not it's a new FPR. Hopefully the FPR connection arrangement on the fuel rail will be OK after all these years .... time will tell!!!!

Bob

[Laird Scooby]

Originally Posted by bob12

Seem to be getting there ..... slowly.

As said TB completely cleaned and now new dissy cap/rotor fitted (a pain in the backside!) together with plug leads fitted this pm. Coil terminals cleaned up.

Test drive much much better but revs now idleing about 1,100 rpm rather than 8/900 rpm. Suspect car running a bit rich.

Immediately after return with engine stopped pulled the pipe off the FPR (didn't want to do it with engine running for fear of petrol spray if faulty) dry and then, ooooh .... a small amount to petrol appeared at the connector on the regulator.

Not good!! Clearly the diaphram has gone and that's propbably why there was a small puddle of petrol at the lowest point on the manifold at TB connection when I took that off as the petrol was immediately below the FPR vacuum connection on the manifold.

Have now received a metre of new injection pipe and clips for the return line per Dave's recommendation so the next job is to swap out the FCR from the breaker and see if that's OK. If not it's a new FPR. Hopefully the FPR connection arrangement on the fuel rail will be OK after all these years .... time will tell!!!!

Bob

Just smear a bit of silicone grease on the "O" ring on the replcement FPR Bob and clean the entry point on the fuel rail. That should sort it out for you.

Keep an eye on the replacement if you use the used one, the diaphragm may have gone brittle and dry while in "storage". While it might seem fine at first, it will take a while before it becomes fully flexible again and may crack during that period.