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Engine Cuts Out -- help [from the archives][ALL/1998] posted by Dave Deford on
Monday, 31 March 1997, at 5:37 p.m.
My 1972 Volvo 145E has developed an intermittent problem where it will cut out for just a moment while driving. It's like hiccups - once it starts it doesn't go away. It usually begins after the engine is warm and will do it about every minute or two. It has never lasted more than a second, but it causes a jerk and is irritating. I'm assuming it's a fuel injection problem, because I changed to electronic ignition and the problem didn't change at all. I first noticed it about six years a go and it has been getting worse lately. Any ideas?
[Reposted requested by Gilbert Kirk]
The original thread.
Re: Engine Cuts Out -- help [from the archives][ALL/1998] posted by Gilbert Kirk on
Tuesday, 1 April 1997, at 2:55 p.m.
Dave - Have you checked the throttle position switch (part of the electronic fuel injection system)? A classic problem with these switches is that they develop 'blank spots' where the contactor arms have rubbed the sensing strips through and cause a break in continuity at that point. This typically happens in areas where the throttle sits for extended periods over the years. At 35 - 40 mph and at 55 - 60 mph. It WILL cause the engine to cut out as you've described. Gilbert
Re: Engine Cuts Out -- help [from the archives][ALL/1998] posted by dave deford on
Wednesday, 2 April 1997, at 1:58 a.m.
The throttle switch was actually the first thing that I thought of. The original was quite badly worn, and when I checked it I found several dead spots. Imagine my surprise when I put in a new one and the problem didn't go away. It also remained constant when I put in a new distributor and electronic ignition. (It needed the distributor anyway.) At this point, I am in need of another fuel injected Volvo in the Everett/Seattle area that runs well, so I can swap out the manifold presure sensor and/or the injection computer.
Is there a kind soul out there who wants to help diagnose this?
Re: Engine Cuts Out -- help [from the archives][ALL/1998] posted by Jarrod on
Wednesday, 2 April 1997, at 7:50 a.m.
I have been looking for the very same thing: a 142 with D-Jet that works so that I can put in a pressure sensor to see if the ensor is what is keeping my engine from working. However my problems are more than just the hiccups. I can tell you that it is probably not the ECU. I have heard that these things can re-enter the atmosphere and survive. Suspicion of the pressure sensor seems strange in your case. I do not pretend to know intermittency like a friend, but I would think that these units would either work or not work (as was the case with mine, I think).
Of course, you have taken your sensor of to test the resistance: 90 ohms between 7 and 15 (primary) 350 ohms between 8 and 10 (secondary) [these may be reversed]
Of course this does not convince me either if it comes up clean. The thing may have somehow uncalibrated itself. And, as you know the only way to be sure whether your unit is working or not is to put in a sensor from an engine where it is known to work just fine.
In my search to solve the problem with my engine, I had someone suggest to me that I should disable the vacuum advance which is not all that important in this particular engine and gets funky with time if left on. I suppose you could simply tie a knot in the hose to test this theory. Of course, you should plug the manifold side to avoid a vacuum leak if you take the hose off.
Also, the only time my car ever experienced the hiccups was when their was a short, and this was even a problem only when I was going certain speeds. I have seen myself that the wires leading from the ECU to the engine components are prone to shorts. The plastic has broken off on much of my wiring where it has been exposed to heat.
I have not done this myself, but you could take the connector off of the ECU and check each wire from end to end. I think this would be worth the time it would take.
I am not satisfied that I have answered your questions, but I just wanted to share my experiences in this arena. I really think you need not suspect the ECU. Also, the pressure sensor in your case seems to be unlikely. WHen mine went, it shot fire out the ass and black smoke (from the excess fuel symptomatic of horrible fuel mixture).
Take care, -jarrod
Re: Engine Cuts Out -- help [from the archives][ALL/1998] posted by Rob MacTurk on
Wednesday, 9 April 1997, at 8:55 a.m.
I'm having the same problem with '82 240 DL and the cause is a bad connector to ECU. It makes an intermittent connection especially after it gets warmed up. A temporary fix is to pull the connector off and if you look down the female side, you should see two little pieces of metal opposite one another. If you take a straight pin, you can bend them out a bit so they'll make better contact with the ECU pins. This seems to work for a while then you need to do it again. If anyone has a better solution (short of replacing the harness), I appreciate hearing from you.
Rob
Re: Engine Cuts Out -- help [from the archives][ALL/1998] posted by Stoney on
Wednesday, 9 April 1997, at 9:19 a.m.
Rob Mc, I believe you can order a new connector and new pins from Volvo and replace the old ones. My old 82-245DL had a constant problem w/ intermittent and this cured it. It is cheape than a new harness.
Re: Engine Cuts Out -- help [from the archives][ALL/1998] posted by John Ellis on
Wednesday, 2 April 1997, at 9:12 p.m.
Dave, I have experienced this same problem recently. I own a 1991 940SE and recently experienced intermittent cutouts. Fortunately, or unfortunately the problem corrected itself before I could find the problem. The only attempt at a solution was replacing my fuel filter. This didn't seem to work. The weather is now warming up in my area and I suspect possible moisture/condensation may have been a contributor-- but that is just a guess. It sounds like your problem may lie deeper than this. If anyone has a list of troubleshooting procedures I would be interested in seeing it.
John