60mph limited

[sega]

i've got a phase one stock gt turbo with a strange problem. It doesn't pull over 4500 revs and doesn't go faster then 60mph ever. It pulls good but when you reach 60 is hasitates and the turbo drops off. Allready changed: carb, fpr, pump, fuelfilter, plug wires, dizzy+cap, renix. Don't think it's the tdc sensor because it stays at its revs on the clock.

[youngscottie]

Are you getting full throttle?
Its normally the little things that catch us out

[michael tierney]

could be a blocked filter in the fuel tank or the pressure switch on the boost pipe has been adjusted wrong

[NRG]

Unplug boost switch on intercooler hose and try it.

[Sparkie]

i think that your dizzy is out.
as the spark advances it misses the end of the electrical contact on the inside of dizzy cap.
check the contact inside the cap - if the oxidation is all off to one side, then that will be your problem.
you need to rotate your dizzy body slightly.

[sega]

Hey the boost switch was allready unplugged.
Today i put in a new feul sender, checked output on fuel and that should be enough, inside the dizzy i see nothing abnormal, checked vacuum hoses but no difference, hose to the top of the fpr is also fine and airfilter also...
Any other ideas? It drives great till you reach 60mph

[Markey Mark (BD)]

Did you measure fuel pressure going to the carb?

I'm only thinking its possible fuel issue as I've just fixed a very similar fault on mates car and it was his pump that packed up.

[sega]

Would this stil be possible with a new pump?

[sega]

Drove it without a fuel filter today still no luck. Also put the live and earth from the battery direct to the pump also no difference.

[Miller]

I agree with Sparkie the dizzy is out a tooth. You need to check it per the Haynes manual.

I had the same problem with bass J Car a few years ago.

Chris

[sega]

Ok will check timing but the didnt have it before so dont know how it could go wrong.
Have also ordered a feul pressure tester so i can test what Mark said also.
Thanks for the help.

[sega]

Went for a drive with the fuel pressure gauge and at 60mph the pump lost pressure from +10psi to 5psi while on full boost. Removed the new pump and fitted a older pump i had laying around. All is good now. Thanks chaps