Help please, 4x4 sapphire cosworth,
Idles rough but disconnect vacuum pipe (and plug it) from fuel pressure regulator and Idles sweet, what's causing this?
Have replaced fuel pump and fuel pressure regulator,is used untampered regulator I put on,
CheeRs Colin

 

Could it be an inlet manifold or TB gasket leak?

 

Cannot find any leaks, sprayed carb cleaner over everything to find nothing,
Is new inlet gaskets,
Will try make pressure tester to check inlet

 

Injector seals?

 

Just gave injectors a good wiggle no change in idle or leaks,
Dodgy fuel pressure regulator?
Seems loads of vacuum, maybe to much? But why?
CheeRs Colin

 

Dodgy reg imo. Vac could be drawing fuel into manifold.

 

What is the idle CO? If shes very lean, then removing the reg reference hose will increase the fuel pressure causing it to richen up which will stabilize the idle.

 

Co was I'm sure about 1% at mot, is msd chip,closed loop,wasted spark, 55lb siemens, will try get it checked again tho

 

Lambda could have died also,

 

Recently new lambda sensor and even tried narrow band off AFR and still no better

 

So more on the history, and problem.

So the car has run fine previously ? Any work carried out before this problem appeared ?

Plugs, ignition system etc all in good order ?

Compression test ?

if CO is 1%, do you have any other mixture data ? or how long ago was that, and how was it running then ?

 

Car ran fine, then on cold starts it would near cut out,when hot was OK but not quite right,
Replaced cts and lambda,
But it gradually got to be running rough when hot to,
afr at idle goes way lean then back to about 14.1 ish,
New inlet gaskets made no change, either,
Compression test was about 155 to 160 on all cylinders,
Tried going richer but it still rough,so put screw back where it was

 

Have tried 3 different sets of plugs to,
Coil etc seem ok

 

You need some way to interrogate either the ecu, or verify sensor readings, as well as checking you are getting fuel injected on all 4 cylinders ok.

otherwise you're just guessing and swapping bits at random which is rarely a good way to cure a fault.

You need to know with certainty they are working as they should.

 

Checked resistances and voltages for sensors at ecu and all seemed within tolerance,
Had injectors out,all spraying the same,
Could ecu cause the problem? No obvious burnt bits or damage inside,
Will pressure test inlet,
Cars my daily but getting tempted to break it now

 

The ecu is possible, but ecu faults are fairly rare.

And if you say removing the vac pipe makes it run normally...would suggest there isnt an ecu problem.

Without some actual live data or being there, very hard to diagnose from afar.

If you say all sensor readings are fine, have you checked fuel pressure ?

From the description of the problem, it just sounds like it wants more fuel.

 

pressure tested intake,loosing about 2psi every 4 seconds,
not sure whether hear faint hissing,cant pin point it anyway,
inlet gasket leak or just leaking through engine?

 

pressure tested intake,loosing about 2psi every 4 seconds,
not sure whether hear faint hissing,cant pin point it anyway,
inlet gasket leak or just leaking through engine?

 

Exactly how are you conducting the test ?

 

made tyre valve plug,pluggedit in end of boost hose into throttle body and used air line to pressurize to 30 psi ish,
was going to book it in to msd but they booked up till end of October,
might give sitech a phone,
thanks again

 

made tyre valve plug,pluggedit in end of boost hose into throttle body and used air line to pressurize to 30 psi ish,
was going to book it in to msd but they booked up till end of October,
might give sitech a phone,
thanks again

 

So the intake is still bolted to the engine ?

With intake/exhaust valves that can leak as some will be open etc, a throttle blade that can leak, an idle valve that can let air pass etc etc

Not really a suitable test.

 

What make plugs and what gaps.

Mark

 

Denso ik27 with a gap of 0.65mm
Ngk iridium iex 9 I think. Gapped at 0.65 and 0.7 mm
Now on ngk bcr8es I think gapped at 0.7mm
What gap would you recommend?

So best pressure testing inlet of the engine?
CheeRs

 

I'm not quite sure what you're trying to achieve with the pressure test ?

Usually a quick visual, or test with spraying easy start around the intake will find any leaks.

Or if you have one of those fancy smoke machines.

But to pressure test properly, you'd need to remove an inlet cam so all inlet valves remain shut, seal off the turbo at the air inlet and that would allow you to pressure test the entirety of the inlet system.

 

Just wanted to rule out an air leak really,
Will try changing plug gaps,

Noticed tonight that the fuse and wire from fuse to fuel pump relay were very hot, wire from battery to fuse cold,so was feed to fuel pump, all new 30 amp wire,
what would cause this?
Wondering if it's related to idle issue,

 

Coolant temp sensor? My saph cos used to run and idle like crap and found to be the coolant temp sensor. I just got a sensor kit from msd I think it was and changed one at a time untill it sorted it but carried on changing the sensors anyway as they were old and gonna fail one day

 

As above it seems to want or like more fuel so it could be the wiring affecting the fuel pump. check fuel lines/filter or it maybe the pump itself?

Also as James said what is the CO reading?

 

Has new cts, new pump,fuel line's look ok no kinks or no crushed bits, still original fuel lines, is it possible they corroded inside and fuel has smaller hole to go through,
Tried to get co checked but was an old guy who was an arsehole so told him I'd get it done at some place that knew what they were doing, lol,but looking like I'll break it by then,
CheeRs again

 

Might be best getting It into one of the tuners? Even though I'm a mechanic myself I'm gonna have to take mine to msd at some point to have the chip etc set up properly as it's started to have a few issues and run a bit rough. I haven't got a rolling road at work and wouldn't have a clue how to use one so got no choice :-(

 

Yeah , msd booked up till end of October, needing it right before that,
Nobody about here worth going to,
It's my daily and has been for Last 12 year, so like it running right,
So tempted in breaking it and getting mk1 or mk2 escort

 

Blimey you've used a saph cos everyday for 12 years? That's awesome mate , you'll get her sorted in the end, wish I lived closer I'd pop round and make 2 heads better than one buddy

 

Thanks, Yeah, as good as every day, done more miles in it than some have done in all their cossies added together, lol,

 

Shame your so far fella. A quick plug into a laptop woud give you lots of answers.

 

Nice mate good man, that's what there made for using I've got to the point with mine before where I've wanted to burn the cxxt but persevered and got fresh heads to look at it with me and got there in the end.

 

Just looked at your pics of it, looks seriously mint! Is it standard or tuned right up?

 

Thanks,
ye it's not standard anymore, 6 degree rear beam,msd wasted spark and msd closed loop 380bhp chip on siemens etc, normally about 32 psi boost,
cheeRs

 

Nice mate I bet that's awesome! Pretty good round town I bet too with the closed loop. What turbo u running?

 

Thanks,yeah it normally goes well, turbo a t34.48 so no lag really,amal valve jetted so boosts from just about 2000rpm,
Yours standard or tuned?

 

Sounds like what I want mine to end up like. What do u do with Amal valve then mate? Not heard of anything done to that before. Mines a 4x4 too, was totally standard when I bought it, got it stage 3 on greens and t3, bloody quick for what it is, must have done it right as everyone I know owns escos and saphs In the club and when I take them out there well suprised lol. Stage 1 was defo more reliable though. I try and do everything myself being a mechanic but it's gonna have to go to msd to sort idle issues out :-(