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im listening intently to all these good suggestions.
I spent the weekend actually working on my 740 not the 240 just because I thought maybe I can fix it's issues up faster and then tend to the 240 with the problem of it failing to acellerate..
the 240 runs smooth as silk when it runs properly so some gremlin crept in , es I can try a different FPR or AMM. maybe the capacitors start to fail in the ECU I tried to recap the one in my 88 Van, almost the same thign really it had 3 or 4 little electrolytic caps. I failed because I clipped a transistor in a slip up so I set it aside and bought a rebuilt one.. I could try to recap one of the volvo ones.
withthe 740 its runnign funny but in a slightly different way, same engine but a year or two newer so it doesn't' have any memory, the check engine light is on and I keep wondering why. the older 240's had a thing on the back of the speedo that I'd reset, so the warning was just a reminder to change the timing belt but I could find no such switch on the back of my 740 speedo.
I thouhgt I might go back to square one and try to adjust the timing on the 240, and check the throttle switch. I noticed that when working on the starter issues that I had recently that if I left the ignition on and reached in there the idle air control valve was sort of vibrating. I pulled another and stuck it in there, changed the little vacuum line for the manifold down to the screen above the flame trap and the one from the FPR to throttle body, not much difference. I sprayed most of a can of throttle body cleaner and sea foam in past the AMM hoing it would perhaps claar some gunk if it was dirty in the throttle body area.
It runs pretty well on power, but idles and shakes in a weird way. I wondered if maybe the balancer shaft slipped or is mis-timed, maybe I should do the belts or at least pull the timing cover and check the marks are right. it doesnt vibrate that bad once it's going down the road under power.
the 240 is 1990 and has a TDC sensor, Ive had issues with that. in the 740 it has the hall sensor int he distributor and it's had issues too causing a no start, obviously both are working now as they do run.
in my ford van, the way the timing is set , there is what ford calls a "spud connector" its a little jumper you can unplug and it disables how the timing is over-ridden by the ICU which then allows you to adjust the timing with a light and turning the distributor. ,Then you plug it back in. Volvo doesnt' do it quite that way but I'd like to make sure the timing is right. if my timing isn't set right maybe that could make it shake like this?
im not finding any leaks, but I could look further. yes Ive seen how any leak especially between the intake and mass meter can make it run really bad.
new motor mounts might not be a bad idea. I've seen cars where I could take a 2x4 and sort of pry up upon the engine to see them broken. Ill check compression to see if any cylinders might have weak compression. maybe I should buy a new mass meter. I noticed that rock auto, at least for a while had just the element so it can evidently be changed,maybe cheaper?
It was all I could do to get the 740 on the road, the signal lights had an issue but it was just a bad bulb socket. I put all the dash back together. although it's shaky at idle , it runs better than the 240 with the stalling out issues.
I still have basically two issues, the 740 runs strong but shakes at idle, its not quite right. the 240 runs but goes very weak on power intermittently.
I think the issues are quite similar in that they seem to relate to them just not running smoothly. both seem to have engine lights on but neither is letting me extract any codes. the 88 740 wagon has no code reader and the 1990 240 doesn't return any blinking.
do the engine check engine lights mean that it has a code stored? or is this something to do with the timing belt and just need resetting? they aren't overheating.
although not related , my 88 ford van also has similar issues, it is missing and running very rough , but running.
I'm ok changing any part but diagnosing these issues seems to be making my hair fall out..
I have a spare 740 standing by, it has a busted windshield and I have a spare windshield but haven't driven it. but Ive been trying to leave it alone and keep it intact, if I need to pull a part for testing I can. its a 1990 and has the code reader.
I have a spare line from the fuel rail to the filter and pump and a spare fuel rail, I was thinking of using those fittings and just connecting it to a pressure gauge so I could install a gauge temporarily where the fuel is fed into the fuel rail. If I can rig that up maybe i can at least make comparisons from one vehicle to another.
can I just use a gauge for air or water pressure? maybe if I can quantify what the fuel pressure actually is it could be a clue or at least prove its not the FPR ? likewise I do have an old vacuum gauge so maybe there are some ways to measure what the manifold vacuum should be, and see if its ok.
I tried spraying carb cleaners and things around the manifold gaskets and couldn't detect any vacuum leak that way. I'm thinking that making a smoke tester to feed smoke in might help decide if I have a leak anywhere that's gone un-nnoticed.
thanks for the great help with this, I'll keep thinking and trying to figure out the basis of all these issues. I'm having quite a time isolating any of them.
sometimes it's a matter of using a process of elimination and used parts going to a drive after swapping out this part or that.. I might hit upon the right thing that way..
just looking for something that make enough of a difference to feel like I'm on to something substantial is a help. right now I'm just confused.
I figured that I found the rough running issue because I did find an injector that wasn't injecting. last year the 240 had one that was stuck on and flooding a cylinder.. but i got through that and it ran fine since. It blew a head gasket and I fixed that. its been ok over winter. for some weird reason the 240 can run smooth has silk on idle once all is working right, but the 740 seems to shake a lot more at idle and has done for a while.
It seems that although that was an issue and I fixed it, it still shakes a lot.. i do have an oscilloscope maybe I could try looking the trace to the coil, or before the powerstage, or to the injectors and see if the profile looks right. maybe I'd see differences in the oscilloscope trace from one car to the next. The cars are all obviously seeing a pulse because they run but maybe something gets goofed up due to bad capacitors in the ECU.. I can swap around ECU"s or ignition modules, not usually the first place I'd start. If I could switch ECU's and see some improvement it might mean something..
Ive primarily run all my cars on higher octane fuel , thinking it may avoid such issues.. I dont really know if that makes a difference but Ive heard it is better for when a car is parked. I haven't noticed any fuel starvation issues like weak acceleration when they get going, any of my cars seem to run ok if it's at full throttle but I think that just masks a lot of more subtle issues like vacuum leaks or timing slightly off, or idle control valve issues.
I thin I have a lot to check but maybe sould first verify if the timing is correct and that the throttle body switch is working correctly. maybe I can probe the idle air valve and see it reacting by way of the throttle body switch being open slightly or closed. i noted it has 3 pins and wondered what the third is for. is it on or off or would it have mid positions? maybe I can blow through it and apply power to check it. or similar. I think some volvo ones have three hoses, these ones just have 2 hose connections. I think my Porsche 944 has the same bosche valve. I sprayed brake parts cleaner and then some some throttle body cleaner in it yesterday, switched it out for another one in the process, I did not see any big changes.
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