1990 940 GLE 16V Automatic ~93,000 Miles Various issues

[billofdurham]

No injector pulse could be the radio suppression relay mounted on the left side of the engine bay near the shock tower.

In 1986 Volvo decided to isolate the fuel injector circuit because of some radio interference created by the pulsing circuit. The solution was to energize a relay (the radio suppression relay) with the pump/system relay feed instead of using it to power the injectors directly. The radio suppression relay supplies the + power to the injectors. When it's faulty or missing, the radio will work fine, but the engine won't run.

If the radio suppression relay is suspect it can be checked by switching the leads with the electric cooling fan relay which is identical and in many car lines is located right next to the radio suppression FI relay. If the fan stops and the engine starts, that was the problem.

Bill.

[girlbunny]

Thanks Bill

I passed that info on to the mechanic and he said he'd check it. He and another of the mechanics have spent the entire day today (along with half of yesterday) trying to figure out the problem. Initially they thought the ECU. The last time I spoke with them, they weren't too sure the ECU was the issue. In fact, from the wording of the woman who answers the phones there (she's been acting as a go between for most of my harassment LOL) it sounds like they almost can't find the issue.

I don't know exactly what they've checked. Getting information from them on that score is sketchy at best, since I'm mostly going through the receptionist (aka main mechanics wife). When I have spoken to the main mechanic, he's been baffled... and obviously somewhat frustrated since they can't actually do any work on other cars while they're trying to get mine diagnosed.

Basically, I had to explain to them exactly WHY I need her running as quickly as possible (I'm out on my ear in two weeks if I don't find a place to live... and I can't get a place to live if I don't have a car to look at houses in order to fill in relevant applications. Vicious cycle, I dunno how people without cars actually GET houses!) I suspect that's why he's dropped everything to find the problem, but she really isn't helping on that score.

So... I know that until I can give a full list of what they've already checked, you're kind of clueless as to what actually may be causing the problem... but are there any potential ideas? Basically, all I've been told is that they've checked "all the usual things", I know from random comments that they've checked the wiring. I told them initially to check the fuel pumps and intake manifold... as well as looking for vacuum leaks. I told the guy this morning about that one particular relay. They apparently checked relays yesterday, I'm not too sure which ones they checked though.

Apparently the poor guy has even been online to try to find her issues. Not sure he's been to helpful forums like here though

Any other potential ideas will be most appreciated. I won't find out until tomorrow what tests they've already done, that is, if they tell me. After all, women don't generally get quite the same professional courtesy about cars and their innards

[billofdurham]

The radio suppression relay isn't in the main relay board and they may not have checked it. It is peculiar to the Volvo range of cars using that particular fuel system. Most non-Volvo mechanics don't know about it and quite a few Volvo mechanics forget it is there.

My excuse is I am not a mechanic and I did forget about it until you said there was no injector pulse.

women don't generally get quite the same professional courtesy about cars and their innards

You do if you convince them that you know as much as them!

Bill.

[girlbunny]

I did tell the guy exactly where to look for that relay... but that doesn't mean he actually listened.

I'll ask when I call him this morning (they won't open for another four hours) and see if he has checked it.

Of course, if he hasn't checked it yet, and he finds that IS the problem, I would hope that he wouldn't be charging for the extra full day of time that it took to check, since first thing yesterday morning is when I told him to check it.

Unfortunately, right now I'm the mechanics worst nightmare. A woman with pretty much no money, who constantly rings, and urgently needs the car back LOL

Just so that I know... you mentioned that the leads for the electric cooling fan relay were near the radio suppression relay... Well, you said radio suppression FI relay - is that the same one (in the engine bay left side near the shock tower) or are there two radio suppression relays one of which is labelled FI (which I'm presuming means Fuel Injection?) How hard is it for them to find the leads to the cooling fan relay? These people specialise in fuel injection systems, so they SHOULD be able to easily, but if I need to explain, all I know is that you've said it's right next to it.

If it IS this relay, hopefully they're easy to find replacements... one would presume that all Volvos have this relay, so I should be able to contact the Volvo specialist wrecker and it will be identical for every Volvo. Always a good idea to check, just in case

Thanks again!

[billofdurham]

I'm doing a good job of confusing you, for which I apologize.

FI = fuel injection and found its way into my post because I was copying from my not so little cheat book and that was how my friendly Volvo tech had written it down.

Now that you have queried the exact locations of the relays I have dug a little deeper looking specifically for the 16 valve engine and come up with a diagram:

Photo0001.jpg (23.85 KiB) Viewed 1406 times

Relay 1 is the radio suppression and relay 7 is the cooling fan. If I was checking this I would take the cooling fan relay to the radio suppression relay wiring, connect it up and see if we had a starting engine. The two relays are exactly the same - Volvo part number 1323592.

Why did Volvo put relays in different places on different models? Answer: to make it more difficult for DIY and non-Volvo techs to work on the cars.

Hopefully this will help.

Bill.

[girlbunny]

Again, I'm delayed with myresponses. Sorry about hat. I've been in the middle of moving house and getting online hasn't been a priority!

Firstly, I gave up on the morons who were looking at the car and had it towed an hour away to the Volvo specialist.

Naturally, it WAS a relay. I went to pick up the car after it was fixed, drove it around for a couple of hours, had to stop back at the mechanics briefly... and the car wouldn't start again. The mechanic took a look, and one relay literally exploded in his hands.

So, a few days later, after new relays arrived, she was working again. I'm still a little leery, mainly because she now randomly dies when I stop at an intersection, and the idle is a bit low for my tastes, but she's going.

I still don't have a reliable speedometer. It's so random it's stupid. I also now don't have a reliable petrol guage. For a while there I thought she was spewing petrol because I could see the level going down in a five minute trip! However, when restarting the car later, the levels were up again, and seem to randomly either go up, or down depending on some weird feeling it has at the time. I can only presume that it's an electrical issue and that may be what's causing the problem with the speedometer. Oh, and when the headlights are on, if I indicate left, the wipers turn on. The wipers go on and stay on when I'm using high beam.

So... she loves to throw me weird curve balls, at least. Let's hope these are cheap to fix. The latest fixes have cost way too much, what with massive towing fees and incompetent mechanics who don't bother listening to what a female suggests!

Thanks again guys

[billofdurham]

I was wondering if we had upset you!!

Some progress but still not quite right. The instrument panel problems sound like either bad earths (grounds) or the board in the speedo head is flexing and cutting the power. The earth points are in the right front footwell behind the side trim panel. You will also find that the relays for the wipers and headlights are earthed to the same point so there may be a connection.

The idle is not adjustable but a low idle can be caused by fuel injectors; intake manifold leak; coolant temperature sensor; throttle switch and connector; distributor. You can check the majority of these yourself so just shout if you need any help on the checks.

Bill.

[girlbunny]

Thanks Bill I'll have to find my book in amongst all the boxes I still have and figure out what I'll need to do to check the earth first. It sonds like a real possibility for these isses! Could the speedo issue poentially be caused by the same thing? It would be nice to have a reliable speedo again LOL

[billofdurham]

Yes, they all earth at the same point.

Bill.

[girlbunny]

Cool! Is it sad that I almost find the thought of having a working speedo exciting? LOL