1.7 TURBO ENGINE IN A R5

[daveb948576]

I COULD REALLY DO WITH YOUR HELP WITH THIS ONE.

I COULD BE GETTING A R5GTTURBO WITH A 1.7 VOLVO ENGINE AND SOMEBODY HAS SAID TO ME THAT THE ACTUATOR HAS BEEN FIDDLED WITH AND CAUSES THE ECU TO SHUTDOWN IE LIMPMODE. IS THIS TRUE?

IF SO WHAT IS THE BEST/CHEAPEST AND MOST EFFECTIVE WAY OF SETTING THIS UP. BEARING IN MIND THAT I WOULD WANT TO DO THIS MYSELF AT HOME.

CHEERS GUYS

[foggyjames]

Welcome FWD French friend!

Step one: Take off caps-lock

Step two: Determine exactly what is wrong, and fix.

Start with a calibrated boost gauge, and note the boost pressure immediately before it goes AWOL. I don't have the figures to hand, but it ought to be sub 10PSI for sure. It sounds like someone has gone a bit mental with it, and wound the actuator right in/out, and is triggering the overboost switch, which will do anything from retarding the crap out of the ignition timing, to cutting the fuel. I'd be surprised if it really is going into limp-home (I'm not even sure they're clever enough to have a limp-home mode). I suspect there's a chance that the same level of understanding of the 400 series turbo ECU has been applied to how to adjust the wastegate actuator rod.

If you want to up the boost, get an MBC, or even better an EBC, do it in stages...1psi at a time, and LISTEN *VERY* carefully for the onset of detonation...it sounds kinda like marbles in a tin, or peeing in a bucket! Detonation = extreme heat = melted pistons. Having said that, you'll probably find that this overboost switch will limit the potential for damage. Eventually you may want to remove it, but if you do so, you're removing a major safeguard from silly mistakes. For example, without it, the previous owner would probably have a dead engine right now.

If you want my advice, return the engine to stock boost levels, then start reading about the engine, it's potential, and what needs to be done to safely raise the boost level. You can destroy your engine in seconds if you get it wrong enough! If in doubt, enlist the services of a professional - £50 consultancy is a lot cheaper than the cost (and hassle) of even a scrapper's engine. Most people are too reluctant to recongise when they're out of their depth, and bring in someone who knows what they're doing. I've seen it a number of times, and it usually ends in a melted engine

cheers

James