Been havin trouble with a mates car it holds back at 4k and its doing my head in.

Checked all loom fitted new connectors on 90% of it bleeped out all wires and ohms check.

New sensors
correctly gapped tps
as above with all phase and crank
tried changing ign amp. leads plugs ecu.fuel pump,pressure reg

BUT its intermittant
if you drive steady its fine all the way any ideas to try

People who know me no im not stupid but this issue is pi**ing me off

cheers

Paul

 

fuel filter ?

 

New

 

Spark plugs

 

New 071'S gapped to 0.6 even tried PP8'S

 

Is there a fuel pick up pipe in the tank?
I've head of the bottom half of the pipe coming loose but unsure of it was a sapph or esc etc, have u tried it when the tank is full to eliminate that side of the fueling

 

its a mk2 escort so no issues there 15mm outlet bottom of tank into inj pump then to filter.

 

when it gets to 4k
does it just go flat and not pull?
or is it like a missfire/rev limiter?
does it still do it if you let the revs build up on part throttle?

 

hits a brick wall feels like fuel starvation. drive it off boost all the way

 

yeah could be fuel starvation,
check the pipes for any damage or anything that could restrict the flow,
pump could be on the road out,
are the lines big enough to flow enough fuel at high revs(assuming its a new build)

 

any other suggestions

 

Have you Plugged the knock sensor wire on the loom onto the crank sensor or knock onto the crank.

 

does it have a dump valve?
could be the dump valve opening when the boost is up?

 

no knock sensor its on 2wd loom

good idea tho

 

Good idea was going to try that but then forgot
will give it a go it must be something really silly....

 

This problem is heat related mate took car out when cold and it was fine untill it warms up..

Ideas please btw its not running coolant through turbo.

Also has no cold start so im looking at cts wiring asap

 

What's the fuelling like under load when it's hot? Don't forget it will be far richer when the temp related correction is being used.

 

Happens quick James the afr still reads ok but really would'nt wanna keep my foot in just in case don't want to cause myself more issues.

will check cts wiring and prob by pass it for testing but will still need to link pin11 for other sensor earths.

whats your thoughts?

 

Dizzy cap, Fuel pressure reg, fuel pump not flowing enough


Has the car ever run ok?

 

Yes and all changed for ones off my own car.

its intermittant so a real ball ache to sort.

 

Does it have a heat shield fitted to the turbo?
Totally clutching at straws, but I just remember a post from ages ago that msd stu made, about 2wd looms breaking down with heat from the turbo especially if they don't have a shield..
(seem to remember a picture of a totally melted loom actually )

Although I'm sure you've checked all that actually.

 

good point but he loom on this is all intake side even the amal valve is located lower down.

 

Have you done wiggle test on the loom to see if you can get it to stutter standing still?

My old Saff wore the loom insulation the bend where it comes over the back of the plenum and that gave high rev boost probs, also I've stripped looms to find the injector wires burned together where they bend over to the injectors. Ill dig the graph out to see if it starts at 4k because I had it on the rollers while it was doing it.

 

I had this exact problem. I wouldn't have said until you said only when warm...

The fuel filter suggestion above was what I needed along with a new tank! We dropped the tank and the hose on the top just snapped off its mount. It was rotten. We poured out the petrol and it was BROWN.

Changed tank and filter and all was well!

I couldn't understand why it was only when warm though

 

Looms been out and i've checked every connection and wire even changed all plugs to be sure.

 

Tank is a mk 2 escort std tank with a 15mm outlet at bottom feeding the pump. we used a swirl pot set up but the feed pump was'nt man enough to cope hence why i done the above which is a proven mod.
Now after i done this is was fine so we thought ok its sorted only to find its now back.

As said its does it when warm cold its fine so the answer lies there.
could be as simple as charge air temp. or fautly wiring to either cts. or again a faulty 02 sensor

 

That the problem with looms when your testing them they are fine but if the engine rocks tugs on the nicely cable tied loom caused the prob.

real arsehole one I had was when the fans came on the car died whilst driving but fine stationary.... Was the CPS wire being blown by the fans which caused a break and car dies!! But it all tested out fine.

 

your correct a wiring fault can be a pain to rectify might bleep out ok and give a good ohm reading but under load is a different story

Hence why ive made a lead to test sensors will try as soon as poss

 

Cool

you know what makes a nice handy tester an abs ecu plug made in to a breakout box.

 

So after a chat with mate it turns out to be not heat related.
So back to square one

He say it drives fine if you fettle the throttle but if you boot it holds back i'm still under the impression its fuel related.

So its a case of back out with the afr and check fueling again but this time keeping throttle on while it happens.

Bloody cars eh

 

Map sensor

 

Its new but i've changed for a spare will put mine on it to be sure.
I know from experience you can't trust new parts.

Will change fuel reg for a 4x4 one i have inc rail. so will have to find the adaptor bracket i made.