View Single Post
flightlead404 flightlead404 is offline
Registered User
Join Date: May 2015
Location: Secret lair deep underground
Posts: 1,333
Originally Posted by Alan L View Post
I agree - it seems like a bit of a random approach. You can tell/check whether the fuel relays are working etc. We are missing a lot of useful information to make a considered attempt at identifying the issue. The WUR would be one suspect and he seems to have checked that? But it would be useful to have the numbers that he must have checked, rather than 'OK'. Did he do a boost dump WP test? I am wondering if that is what he is referring to with 'loss of fuel pressure on boost'. This can be rectified if the issue - but we need to know what the data is. Has he hooked an AFR gauge in - that would tell us/him a lot. You say it is leak free. Maybe, maybe not.
The number of people who have posted here saying they don't think they have any leaks, then.........
It may even be an IC seal lifting on boost, and 'sealing' when not on boost. The way I check these for sure, is to pressurise the whole system, from the intake elbow by the airplate. To 5 psi. You will be surprised where the air finds its way out.
We really need some solid info to follow a solid track to isolate the issue. There are a multitude of places to throw darts at. It has all been done before. Just need a systematic approach where we can confidently eliminate possibilities.
I concur. Based on what I see here I don't think the "mechanic" knows anything about these cars. Were the basic CIS fuel pressure checks done? Fuel delivery rate tested?

When boost comes on with a US 1986 turbo WUR the control pressure is supposed to drop ~0.85bar, idk if the WUR in the 85 Euro does the same but I expect so. A drop in control pressure richens mixture, I wonder if that is what the mechanic is seeing that makes him think there is a loss of fuel pressure on boost.
Old 02-24-2018, 08:02 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)