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Title: VRIS and PCM removal Post by mike on Nov 28th, 2006, 12:40am Hello there! I just registered today, got a nice welcome message and already I am seeking advice... This is a tad long winded but please! bear with me. Ever since the demise of my trusty Granada/Scorpio III (autobox went south, slowly being rebuilt) I had been looking for a Scorpio II. After almost two years I finally found a nice Tourmallard green Cossie with 160kkm on the clock in Northern France. Driving it back home it soon became clear there was a problem: the engine doesn't miss a beat but the car is very sluggish. At 90-100 kph it makes a kind of hollow sound while it feels like towing a 3 ton trailer uphill with the handbrake on. Not my idea of a 200+hp motor! The only way to get any pick up is through kickdown and it doesn't start to push hard until 120-130 kph. And yes, I'd read about the infamous 24V flat spot but this is neither flat, nor a spot: it's a trough! So I did some reading on "The best auto and car web site in the world" until I came across the bit on VRIS (aka VIS, aka "variable resonance intake system") and that got me thinking. Off goes the cheesy cover, start the engine and watch the VIS throttle link : Ha! Ha! Nothing moving! I disconnect the hose and get the Mityvac: yes the actuator works. The hose is hooked up to what looks like a plain vanilla solenoid located just in front of the windscreen washer reservoir; pulling the other hose from the solenoid elicits a psht sound : the solenoid is connected to a small vacuum tank a few inches aft. Big smile :): the solenoid is not doing its job! By chance I have a similar solenoid salvaged from a Mercedes which I am able to hook up to the Ford connector: still no go! I then find out that the original solenoid is shorted! Checking the voltage on the connector I get 12V between the yellow/purple wire and earth, while the white one is neither live nor earthed. Enough to wipe off the big smile on my face :'( as I realize that: 1) The power connection to the solenoid is not fused (Thank you Ford!) 2) The solenoid is presumably energized by the engine ECU (aka PCM) by connecting the white lead to earth below 3200 rpm. The inescapable conclusion is that either the white wire between solenoid and ECU has melted somewhere (hopefully) or something has fried within the ECU itself (ballast transistor?). Either way, I need to get to the ECU. Unfortunately Ford is not very consistent with its own terminology (or shall we call it lingo?) and there is no mention of VRIS anywhere in the diagrams. It took me forever to figure out that what should logically be labeled as VRIS solenoid or such, is in fact called "Intake air control valve", item Y67 (not to be confused with the idle speed control valve, item Y13). So far so good: I now know that my white lead is connected to pin 44 of the PCM. Off with the glove box, I am able to remove the PATS module which sits on top of the PCM and now I am stuck: This thing is encased in a plastic/sheet metal contraption held together by a bunch of rivets. I cannot believe that you have to drill out these rivets in order to remove the ECU, or even the connector! There has to be some trick. So please! fellow scorpioites, and even though I am only a newbie, let me in on the secret of PCM removal! Mike |
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Title: Re: VRIS and PCM removal Post by Simmo on Nov 28th, 2006, 8:45am Yes you do have to drill out the top three rivets. This allows the security panel to come away so that you can access the PCM and its multiplug connector. There is an excellent write up HERE (http://www.fordscorpio.co.uk/pcmrepair.htm)by one of the members as to how he repaired a PCM and it may help you. |
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Title: Re: VRIS and PCM removal Post by mike on Nov 28th, 2006, 11:46am Thanks Simmo! So I will have to get the drill out after all. Makes me feel like a burglar :-[ Cheers, Mike |
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Title: Re: VRIS and PCM removal Post by mike on Dec 1st, 2006, 7:12pm Bad news: I ended up having to drill 6 rivets to get the PCM out, but that was easy. Checked continuity between pin 44 and the solenoid multiplug: wiring is not at fault. That PCM was a pig to crack open. The casing is not the same as Darren's (see the PCM repair page) and is held together by 6 bolts, two of which have "tamperproof" heads and require a special bit. Had to go to town to buy the bit but then the bolts where so tight, the heads rounded out. Had to resort to the grinder ::). Ugly! Finally I was able to trace the connexion to pin 8 of a 16 pin DIL chip labelled 71001FB/903T01. A bit of googling tells me it is a quadruple output buffer which sinks its outputs to ground when told by the logic upstream. The problem is that there is no provision for current limitation! :o So it is a foregone conclusion that the solenoid took the chip with it when it shorted. Replacing this chip is not going to be easy: first I have to find a replacement (and I have no idea where) and then it will take a steady hand to perform the surgery... At this point I am probably better off trying to find a replacement for the whole thing. So I am in the market for an EECV with part number 95GB 12A650 GF, or better 95GB 12A650 GH. Cheers, Mike |
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Title: Re: VRIS and PCM removal Post by harry.m1byt on Dec 1st, 2006, 7:42pm on 12/01/06 at 19:12:13, mike wrote:
For the IC you might try emailing - rfq@contact-electronics.net |
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Title: Re: VRIS and PCM removal Post by Snoopy on Dec 1st, 2006, 8:11pm Are you sure it is the EEC and not blocked cats... The cats if they break up and block the exhaust can some very strange effects....Just like you descibe .. I know from past experience. |
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Title: Re: VRIS and PCM removal Post by hellblue on Dec 1st, 2006, 9:48pm Did you try fixing the VIS valve in position to give full air to see if this is the only problem? A way round VIS control would be to use a shift light set to 3200 rpm to activate the soleniod valve. |
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Title: Re: VRIS and PCM removal Post by mike on Dec 1st, 2006, 11:05pm Harry, Thanks for the tip. I'll try to contact them. Dave, There is definitely a problem with EEC as it should try to close the VIS throttle below 3200rpm regardless of other conditions. The solenoid failed with a short and something had to give. The car just passed emissions so the cats are probably OK. Gary, I have thought about controlling VIS directly but I don't like the idea too much other than as a stopgap. What do you mean by a shift light? Mike |
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Title: Re: VRIS and PCM removal Post by howiedintheplace on Dec 1st, 2006, 11:11pm Well if your sure it's the VIS this is what it should do. It does not usally work when you simply rev the engine up as it depends on load too. Below 5000rpm & no load valve stays open. If engine is under load then the valve will shut below 3500rpm. Above 3500rpm valve will open. Above 5000rpm the valve will shut. & yeah I think your wasting your time messing with the ECU just get another. |
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Title: Re: VRIS and PCM removal Post by harry.m1byt on Dec 1st, 2006, 11:27pm As there does seem to be some confusion over whether there might or might not be a blown output from the ECU to the solenoid, might it not be a good idea - to drive it on the road with a small wattage test lamp or meter set on 12v range to watch and see what it does? |
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Title: Re: VRIS and PCM removal Post by mike on Dec 2nd, 2006, 12:37am on 12/01/06 at 23:11:40, howiedintheplace wrote:
Ha! This sheds a new light (and hope...) on the situation. I was working on the assumption that the VIS throttle should always be closed under 3200rpm. I will do a road test tomorrow with a known working solenoid and monitor the voltage as Harry suggests. Cheers, Mike |
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Title: Re: VRIS and PCM removal Post by mike on Dec 2nd, 2006, 7:28pm Huge improvement! :) After hooking up a standard solenoid I ran two wires from the multiplug to the top of the dashboard. This way I was able to monitor its behaviour with a LED (in series with a resistor). And it works! The solenoid opens and closes EXACTLY as howiedintheplace described, including the 5000rpm cutoff (not easy to find a suitable stretch of road to test that one ;D). And the car now drives so much better, the difference is amazing! So I was wrong in thinking EEC was at fault: the output buffers must be current limited after all since they survived the short. Thanks to all for the help, with special mention to howiedintheplace who put me on the right track (ironic as, using forced induction he should need VRIS the least ;)). May I suggest the VIS (http://www.fordscorpio.co.uk/vis.htm) page should be updated as it is a bit misleading now: the VIS throttle will NOT close unless the engine is under load, so there is no way you can perform a standing test of the system. I am not fully satisfied yet as there is still a flat spot in the 2500-3000rpm range with a kind of booming sound. It looks minor though, compared with VIS failure. I suspect EGR or maybe a small air leak. Cheers, Mike |
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Title: Re: VRIS and PCM removal Post by Octavian_P on Dec 2nd, 2006, 9:07pm Verry nice write-up, it will be nice to have a new article on the site ;D |
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Title: Re: VRIS and PCM removal Post by howiedintheplace on Dec 2nd, 2006, 11:04pm Well done Mike. I had to work it out myself too a long time ago. Then I came across some Ford tech stuff that said it closed up again at 5000rpm + which I didn't realise. |
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Title: Re: VRIS and PCM removal Post by scorpio_man on Dec 3rd, 2006, 11:54am hi there i saw the vis valve working on tintin's car when he had it on the rolling road. i was at the noisy end, that's why i didn't see the bit of cat flying out the exhaust! i did wonder why sam was waving his arms about! ;D |
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Title: Re: VRIS and PCM removal Post by tintin on Dec 3rd, 2006, 12:38pm }{ }{ something on my car works ;D i took a few steps to side and hid behind the wall after the first few clouds of black smoke, thank goodness, so i didnt cop the shrapnel reminds me, must get Call of Duty back on my machine..... |
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