Took my 89 240 DL to a 'reputable' mechanic that works on Volvos (no Volvo dealership would even touch my car, which is why I would never buy a new Volvo).


Here's the problem:

Mechanic says the Jetronic module is bad. No signal to injectors, no error messages at any diagnostic level.

Went through three computers and every computer (which has been bench and road tested, and after the mechanic says it 'failed', it was re-bench tested and re-road tested and all three computers are fine).

The mechanic claims that he checked all wiring, fuses, fuel pumps, fuel pressure, fuel pump relay, the injectors themselves, the mechanical aspects of the engine, you name it, he claims it is all good. Yet, every time we install a new, perfectly working Jetronic unit, no error codes are produce, nothing is wrong, yet every time we change out a computer, the mechanic claims that the Jetronic unit has a failed 'injector section', which is utter BS because when we plug it into another vehicle of the same year and identical model, the Jetronic unit works just fine, and does so across three specimens of the same year, model and specs. We even sent all three Jetronic units off, at great expense, to be checked and all checked out 100% within specs, nothing wrong with the Jetronic unit(s).

Yet, the mechanic claims that all three units have a failed "injector section".

Yet, when I send off the Jetronic units to have it checked out, they say the units are in 100% working order.

Oh, and yes, the ignition module is just fine as is all electrical and mechanical components.

We have literally everything, including the injectors replaced, the wiring harnesses, the Jetronic unit, checked the fuses, you name it, we did it, and with extreme expense.

Yet, we have the same problem. I am beginning to think min mekaniker ä en skitstövel (pardon my Swedish).


Anyone ever run into this problem?

 

Find a different mechanic.

So, engine doesn't start?


You'd want to post your problem here. You'd also want to post a location so people can recommend you a shop.

http://forums.turbobricks.com/

 

Will give them a try. Thanks!

But, I've gone through every mechanic within 100 miles with this car, and everyone one of them gives me the same line. The Volvo dealers won't look at anything older than 4 or 5 years. If the windshield wipers are bad, they blame it on the computer and want $1000.

I junked a 5 year old Volvo last year because Volvo couldn't get parts for their own vehicle after 5 years.

Thanks.

 

Tried to register on that site and cannot get a confirmation email to complete the registration.

At this point, the car is going off to the crusher as soon as I can haul it off. I will never buy a Volvo, new or used ever again. I have been burnt twice, and I will not get burnt a third time.

 

Note: Tried registering on the forum you referenced. Cannot register. I never get a 'confirmation email'.

 

Obviously the jetronic is Fine! Find another shop, where are you? Too bad you wasted 3k but that's the way some shops are!

 

Swapping ECUs is a very expensive method of diagnosing no-start conditions. Really some diagnosis is in order here. First, where are you located. Your last statement regarding junking a 5 year old Volvo cause you couldn't get parts leads me to believe you do not live in the United States. If not, my assumptions about the type of fuel injection your car has may not be correct.

The '89 240 in the US should have the LH 2.4 fuel injection system. Assuming you have this version, you should be able to hear the fuel pump run for a second or two when you turn the key from the off to the II position. If you don't hear the pump run, then there is no way the engine will run. The pump is under the car under the rear seat of the driver side (left-hand drive cars). If you can't hear it from the passenger compartment, have a buddy turn the key while you listen for it outside the car. If you hear the pump run, then you should have fuel.

The next is to verify that the you have spark. Any good or even backyard mechanic should know how to do this. Without fuel and spark the engine won't run.

 

OK, so here's were I am at with the 89 240 DL (which was used in Sweden and imported to the US). The problem is that this model in 5 speed manual was not sold in the US until 1990, the 89 being strictly a European issue (at least from what Volvo tells me), but you can get the Jetronic ECUs for them all day long if you know where to look for them (I've just turned up several that cost me about $50 each, and all of them test out just fine).

So......

I obtained yet another Jetronic ECU and had it bench tested, tested in an identical 89 240 DL and it worked just fine. I bring it to the mechanic and he plugs it in. The car started just fine.

The mechanic proceeds to test drive it all over creation and had absolutely no problem whatsoever. That is, until he returned to shop, hit a bump in the parking lot and the engine just quits.

What makes it strange, the mechanic then pulls a code that says nothing is wrong at all, but once again, the fuel injectors will not activate via the diagnostic mode. And hence the same problem once again.

I contacted an engineer at Volvo in Sweden who was gracious enough to take the time to send me the schematics for the whole Jetronic system for that year and model.

He was also able to tell me that if the section of the ECU that controls the injectors failed, you would either get every known error code or a totally unresponsive ECU and nothing in between. And, you would most certainly never get a 111 code at any level on the diagnostic interface if the ECU totally failed or the injector section totally failed (which would, in turn, result in a completely toasted ECU that would not throw any codes whatsoever).

This problem (the engine cutting out) initially started when my wife hit a bump in the road going up-hill (if that matters), but the occurrence of the problem increased in frequency until one day the car just wouldn't start.

If you physically move the car after such a failure by jostling the body just right, the injectors begin to operate again. If you hit a bump in the road, it quits again.

As an additional bit of information, there are obviously four injectors on this engine, and, according to the design specs of the Jetronic ECU for this model, all four injectors inject fuel simultaneously in relationship to the demand for fuel and not in relation to which cylinder is taking in at any given time. The physical wiring indicates that the injectors are wired in parallel so as to prevent the entire system from failing should just one injector fail.

That said, there are several items that interface with ECU that would affect the behaviour of the Injector section of the ECU:

1. Throttle position sensor

2. The O2 sensor

3. MAP sensor

just to name three usual suspects.

But since any failure of components of their related circuits would throw an error code, of course, with the exception of the injector circuit (which is tested by activating it via the diagnostic interface).

Since each time the same problem occurs with a good ECU which tests good even when this problem occurs, the only thing that would be possible is an electrical fault between the ECU and the injectors (and Volvo is notorious for using electromotively disparate connectors on their wiring, resulting in a corrosion problem).

Any thoughts or insight on this?

 

(Yes, it is the LH 2.4 fuel injection system as per the specs for that car.)

All that was done. We've got spark, the fuel pumps are going, the pump relay is good. The mechanic got the car running (see previous post immediately above), ran if for an hour in the shop, took it for a test drive, worked fine until he hit a bump in the driveway of the shop and the same problem occurred again - no signal to the injectors. This is what happened intermittently when the problem began and finally became so bad that the vehicle would not restart at all.

Talked to a Volvo engineer in Sweden (see my previous post) and he said the only thing it could really be is a bad connection in the wiring harness. There are no error codes occurring other than the normal codes for nothing being wrong. It's the same problem each time - no signal to the injectors.

If you pull the ECU and bench test it, it tests 100% OK. You put it back in the car, car starts, hit a bump, then no signal to the injectors.

It's really frustrating. The mechanic said he 'visually' inspected the related wiring harness for damage and he concluded there was nothing wrong with the wiring harness nor the injectors. So, essentially for all intents and purposes, the ECU is just fine (and that goes for the other 5 or so ECUs that went into the car, including the original one).

The engineer from Volvo said that it is absolutely impossible for the same exact ECU failure to repeatedly and gave the reasons for it (see my previous post) and no electrical overload sufficient to damage an ECU would occur without it resulting in a totally unresponsive ECU.

'Tis a mystery. But I still think it is a corroded connection or a broken wire in the injector wiring part of the harness.

 

"I still think it is a corroded connection or a broken wire in the injector wiring part of the harness."

That's it! Now someone has to find it and fix it!

 

buy a whole new wire harness for this car, they aren't that hard to replace and the old ones a infamously shotty.

The problem is more likely a short or damaged cable shielding. Possibly field mice thought they would have a go at the cables.

 

That would seem the logical solution at this point. I got a hold of the actual Volvo Jetronic LH 2.4 manual and to actually diagnose the entire problem would take me about an hour, if get the car back from the mechanic who now has had the car for a couple of months or more and he still can't suss out the problem.

Considering the only code any of the Jetronic units throws is a 1-1-1 which indicates that there are no stored error codes and hence, nothing wrong in terms of the Jetronic unit.

Had the Jetronic ECU failed either partially or wholesale, or has become totally unresponsive, then there would be a 1-1-2 code indicating a failed Jetronic ECU (the 112 failure code is actually generated by the diagnostic interface itself in the event that the ECU becomes unresponsive in part, and no codes would throw if the ECU took a dirt nap.

There's only a handful of things that can cause this problem and it's not rocket science, especially if you have the proper diagnostic manual.

All that has to be done is to go at it with a multi-tester and possibly a noid light, and that's it. Just pull the connector from the ECU and measure the resistance on the circuit for the injectors (pins 9 and 18, if I recall correctly). It should be about 4 ohms, if the resistance is higher, one or more of the unjectors is toast or there's a bad ground or bad connection, and then just check each injector individually. Not a big problem. If it's 0 ohms, then it's a dead short, if there's no continuity, it's a broken wire.

It isn't rocket science. But apparently, most mechanics don't look at the actual troubleshooting manuals at all, or they cannot find or get access to the manuals.

Volvo, at lest the corporate entity in Sweden, will usually supply you with any manual you want in PDF format, free for the asking.

Heck, if you have a multitester, an old fashioned oscilloscope and a logic probe, you can get the manuals to test and repair a Jetronic module. Or you can just pay someone $250 to rebuild it. Usually, in this vintage of Bosch equipment, it's a $1 diode that fails (intentionally, as a sacrificial part).

I understand that mechanics tend to be somewhat busy, but when they have your car for a couple of months and it takes them upwards of a week just to plug in a new Jetronic unit, it begins to get a bit much.




Yeah, you can pick up an entirely new set of wiring harnesses for everything in the 240 DL for about $150. Not a big deal. A royal PITA (pain in the ****) due to the tedious nature and the physical contortions one must do to get the job done, but it's not a very complicated process.

The Jetronic fuel injection system (LH 2.4) is not a sophisticated system. I don't even know why they went to the extent of specific application microprocessor based system when they could have gone pure analogue, or better yet, stayed with vacuum controls.

For instance, you can download the entire manual here: https://www.scribd.com/doc/126885359...anual-Complete

 

vacuum controls as in CIS-E ? because its a lot less efficient than EFI, LH or otherwise, AND more polluting. and aging CIS-E systems suffer from lots of problems, like failing modulators. CIS also requires much higher fuel pressures (on the order of 60 PSI instead of the 40 PSI used by LH systems).

pure analog EFI? problem with pure analog is its very sensitive to component value drift, both over temperature ranges, and with age degradation of components. anyways, electronic injectors are an on/off thing, the width of the pulse determines how much fuel. LH 2.2 and LH 2.4 are both digital, 2.4 just has a little more smarts (primarily the crank position sensor, faster CPU doing more calculations).

 

At any rate, this story about my Volvo gets even better. Hold onto your hats for this one...

So, the mechanic is now pulling, "oh, I found the problem. It's a broken wire under the dashboard......I should have it ready by Friday (today) if I didn't burn out the new Jetronic module when I test drove the car last week..." and so forth.


Here's where it gets interesting - I happened to meet up with someone who has the same exact model and year Volvo as mine. He apparently had just had his car fixed at the same shop. He then proceeds to tell me that they just happened to have a Volvo 'in their yard' they could get the parts from. See where this is going?

So, being the suspicious type, I went to the shop and examined my car and have discovered that it appears to have been slightly canibalised to fix someone else's car, which, of course, explains why they keep offering us 'salvage' price for our Volvo. I was also put wise to this scam by two other people who were victimised in exactly the same way by the same shop.

The shop isn't wise to the fact that we know what they did, but they soon will be.

So, we told them if they could not fix the car by today, as they promises, we are going to come and pick it up and do the work ourselves. I figure they will try to give us another line of garbage to try to hold onto the car until we give up and sell them the car for salvage. Of course, they know that if we haul the car off today, we will discover and have absolute proof of what they pulled.

If they won't give us the car back, I will show up with a retinue of State Police and Sheriffs Deputies and simply take the car.

This is getting riduculous.

 

Mystery solved. It was a short in the leads to the crankshaft position sensor. Apparently, the grommet in the firewall pass-though was either not installed at the factory when the car was new, or it disintegrate. Both leads shorted out against the firewall intermittently.

However, new issue has arose (and a new thread).

 

I am no mechanic, but the CPS is the first thing I look at when faced with a starting/dying b230...

And, yes, shop shenanigans are pretty much the norm, that's why I avoid them at all costs. I don't need them, my 6 or so Volvos are much better off not ever going to "professionals"!