Won't Start- Fueling Issue?

[steve@cornwall 100]

Check ecu temperature sensor connection and any inlet pipes you may have disturbed for leaks. If you take a plug out after cranking does it smell strongly of petrol or is it soaked in fuel?

[toolie72 67 1 Cars]

Revving at 3000 rpm then dying is classic air leak-check bolts on side of inlet manifold-if it sucks your finger in you've found it

[mowflow 67]

Just had a look there. Starts up and instantly jumps up to around 4k revs. If I put my foot on the throttle the revs will drop down before climbing back up and I get misfires when doing that. No misfires if just left to idle (hardly an idle at 4k)

 

Bolts to the throttle are tight. Does this need a gasket?

 

Bolts holding the inlet to the head are all tight. Gasket was replaced.

 

Both bolts for the oil filler are in the intake. If I remove the back one so its drawing air it acts exactly the same. I may try PTFE on them to form a better seal.

[Anthony 1,003]

Is the hose from the SAD on the bottom of the inlet? I know from bitter experience if you forget that one (on a Motronic version at least) it'll behave like yours and jump straight to 4k starting from cold.

 

Certainly it does sound like a major airleak somewhere engine side of the throttle body. That the revs briefly drop after blipping the throttle suggests that the throttle itself is closing and cutting fuel on overrun as it's meant to.

 

There's an O-ring sealing the throttle body to the inlet manifold.

[mowflow 67]

I've got no O-ring. Anyone know what size is needed? I can start there and work on checking everywhere else that air could be getting drawn in.

[mowflow 67]

Found it on service box. For anyone searching in future it's 72mm.

[mowflow 67]

Bumping this back up as I'm still having it rev straight up to 4k from cold, run for a bit then die. If you open the throttle while its revving like that the revs die. That's just to summarise the issue from above.

 

So far I've checked all the hoses, jubilee clips are tight, sad hose is definitely fitted. I have also PTFE'd the bolt in the side of the inlet and made sure it's sealed up. In addition I've had the throttle off, added an o-ring and applied some of that stag wellseal stuff when refitted so I'm pretty sure that's sealed.

 

As an experiment I disconnected the MAF. Still revs to 4k but when you open the throttle it revs higher instead of dying.

 

As another experiment I clamped the vacuum hose that runs to the brake thingy and the car wouldn't start at all. I released the pressure on the clamp and the engine idled perfectly. Does it look like this is the source of the issue? I replaced that hose with some new vacuum hose. I have it fitted to the brake thing and have the T branch off to the sunroof fitted but don't have the other hoses on.

 

Sorry for the long post just trying to give as much info as possible.

[welshpug 1,657]

what do you mean by "other hoses" ? you mean there's still a leak?

[mowflow 67]

I mean the other hoses that run off that whole white plug thing that goes into the big olive green brake servo thing. To be more precise the hoses to the sunroof vacuum box (not fitted) and the one that runs into the cabin.

 

A leak seems to be the most plausible explanation for how the engine is acting. I believe I've checked everything apart from the hose above. If it's not that then the only other places I can think to try to solve this are whipping the inlet off and getting some sealer round that gasket and secondly trying the other exhaust manifold gasket I have.

[welshpug 1,657]

fit those hoses, no leak!

[steve@cornwall 100]

Fit or blank off all hoses/ hose connections and also pull back the rubber shield on the afm plug and check all connections are pushed fully home on the individual wires as these sometimes push out of the block when connecting.

Sounds like it's getting all its air from the servo leakage?

[mowflow 67]

I've done something very, very wrong.

 

No joy with sealing the servo pipes off, afm plugs were all fully home in their sockets. Clamped the sad pipe and the vacuum on the side and still the same behaviour. Revving like mad then dying so I decided to whip the inlet manifold off to reseal the gasket...

 

Full of water. The chamber filled right to the bloody top. New engine time?

[welshpug 1,657]

nope, normal with an 8v as it has coolant ports between the intake ports, they are blanked by the gasket on an injection car, so if you didn't drain the coolant then it will leak when you lift the manifold off.

spin it over with the plugs out, spray some wd40 in for good measure, re-assemble with a new gasket.

[mowflow 67]

The valve chambers (probably not the correct term) on the engine, where the injectors fire into were full of coolant. Surely that's not right?

 

If I'm reading your post correct then I think I've maybe been sold the wrong gasket and those holes haven't been blanked.

 

Edit. I have a photo but struggling to upload right now

Edited December 20, 2016 by mowflow

[trogboy 17]

No - if your ports were that full of water before you loosened the manifold the engine probably wouldn't even have turned over and certainly wouldn't have run at all. If you've not drained the coolant before you loosened the manifold, you've broken the seal on the waterway between the manifold and the head and the coolant had drained into the inlets as you've undone the retaining nuts.

 

One of the sets of valves will be open, so you'll probably have some coolant in one of the pistons. As Mei says to avoid damage you need to dry the ports then take out the plugs and spin the engine on the starter. This should blow the coolant out of the exhaust and plug holes - taking out the plugs prevents the engine hydro-locking on the compression stroke.

[mowflow 67]

I'll have hydro locked it then because before I even posted here I cranked it over with a big bar on the bottom pulley with the plugs still in. Arse!

[welshpug 1,657]

I doubt you will have damaged it by hand.

[mowflow 67]

I've now turned it over on the starter with the plugs out. Made a nice fountain. I can't see any puddles when I look down into the chamber's now.

 

The valves are all down and look the same. They weren't originally but my hand cranking put them like this. Is it ok? All 4 look the same as in this pic.

 

 

Edited December 20, 2016 by mowflow

[mowflow 67]

Not sure why I feel the need to keep this going but I do.

 

Finally glued it all back together and have dropped the oil, which had coolant in it due to my error. Put some cheap oil in to catch any remaining water then I'll drop that.

 

I'm now back at square 1 with it not starting again so need to check fueling. Got spark and ignition timing still on and compression is all as it was.

 

I've also bought a new/used throttle body. I found ATKs thread on his car idling at 3k. The screw for my throttle stop is fully wound in, jammed and rounded and the bolts for the TPS are also rounded and seized. I'm hoping this was the issue all along.