adamdrives' 78 242

My 242 had a noisy main pump, and I swapped in a new one... still noisy.

The thing that fixed it was upgrading the intank pump to the 740 turbo spec unit. The stock new intank 240 kjet pump did not flow enough to keep the main pump happy.

That might explain why my 245 never had any pump noises...

I ended up having to have a new hose made with a low side fitting for the a/c, they wouldn't install one into a used hose. A/C has been working great until the used compressor seized the other day, my fault for rushing and not putting oil in. With cold a/c the car was almost dailyable! Just needs radio.

Finally caved and bought the correct windshield from VP. Had the guy who did my 245 glass install it, mostly because he's familiar with these cars and has the correct clips on hand. Waited a few days after install and took it through the car wash at work, leaking pretty bad. Called him and he re-did it on Thursday. Took it through the wash again today after a few warm days of baking in the sun, still has a small leak. Really hoping he can get his act together and make this right, starting to feel like a fool me twice, shame on me situation.

Finally stopped putting off dealing with the speedo worm gear and popped the OD today after work. Finally working right!!! Big thanks to everyone who posted on that, and to @hiperfoauto for supplying the part. Turned out I had the correct gear in my stash the whole time, but wouldn't have known until I compared with the one I bought. Been putting that off for ages. I'm big on having an accurate trip to calculate mpg. Nice to be making some progress with this car.

Something isn't right with the speedo cable tho, it seems like it's too short relative to the sheathing and won't engage fully into the driven gear shaft. Had to mess with it under the car for a bit, was working on the drive home, verified correct speed with GPS, then speedo died completely. I'll check it out again when I drop the trans to do the input shaft seal.

Fuel pump still groans, but car hasn't lost power like it was before. I think I have a spare 740 pump, so maybe I'll try that next.

messed with the speedo cable and got it to seat properly. I had to separate the OD unit and now it has a significant leak from the 79-80 gasket area. There is a plastic or rubber isolator between the gaskets that has a chunk missing, hoping new gaskets will fix the leak.

Finally fixed groaning main pump! Culprit was bad ground wire on sending unit I put in way back when I got the car. Crimped in a new wire and she's finally quiet

Replaced my locked up York today after work and took apart the old one to see what happened. Obviously the bearings have some damage, but the funny thing is that the bolts backed out, nothing broke. Interesting how this compressor is like a tiny engine with a crankshaft and pistons. I wish I had saved the compressor from my 245 when I deleted it, I might have been to use the parts to salvage this one. Oh well.





I only had about 6oz of oil when I installed the new used compressor. Alldata said system holds 10z, is that accurate?

Clutch has started to slip in 4th and OD. Trans is from an 85 wagon. Clutch engagement has always been very low, but it does fully disengage. Could that be because a 78 flywheel is thicker than 85?

adamdrives said:

Clutch has started to slip in 4th and OD. Trans is from an 85 wagon. Clutch engagement has always been very low, but it does fully disengage. Could that be because a 78 flywheel is thicker than 85?

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Pretty sure if the stack height were taller (because of flywheel thickness) the pedal travel would be less, since the T/O would need to travel less to depress the PP fingers....

Yes, the clutch engages early, almost like there is less distance to travel for the clutch.

A customer at the dealer recently brought in his 80 244 with 370k on it. Since I'm the unofficial "old car guy" (read: the foreman doesn't want the headache) it fell into my hands. I was pleasantly surprised when it started immediately and ran at 1500 rpm or so for the first few minutes. My car has never had a working cold idle, so I did some work on that this weekend. Firstly I had the warm up regulator rebuilt because it was untouched with debris in the screens and the car had sat for a long time before I got it. It ran about the same after install, but hey, peace of mind. I tried to move the aux valve adjuster to a higher position, but it was already maxed out. I took it out and found that the shutter was moveable and not frozen. I cleaned it out anyway and found that after it was in a slightly more open resting position, so maybe there an issue. After install, the car ran really high on cold start, 2500 rpm or so. I got it back down to 1000 with the idle screw and drove it around until hot, then reset to spec at 900. when I went to move it a few minutes later, warm idle was a very lumpy 500 or so. The idle screw was probably maxed out because it was the only way to get enough rpm with the aux valve not opening fully.

This car passed smog on the first try with a fuel tank and pump after I got it, so I never touched anything else. I put a dwell meter on it and found that the frequency valve reading was at 20 degrees, but not fluctuating with idle like my others cars have. Holding idle at about 2500 rpm to put some heat in the o2 I got a reading of about 30. After fighting the adjuster screw for way too long (hint: snap on sells a ball point, long Allen that's perfect for the job) I was able to get a reading of 40 degrees or so, but only with the car revved up. at idle, it fell back to 20 degrees or so static. After adjustment, it still has the same low rpm warm start problem, but feels a little punchier driving. I'm thinking maybe a weak o2 is not giving good enough feedback to control the lambda system, which is why it only works when heated, so that will be replaced next.

I need to look into how the car knows to switch from closed to open loop, and how the wur and aux valve handle cold starts. I know the aux valve is just a bi metallic spring, and I'm pretty sure the wur works the same. a weak o2 could explain my low idle when the cars warm enough for closed loop, but leaning out because there's not good signal to enrich. With the o2 disconnected, the idle won't fall below 1500 or so in a drive around the neighborhood.

dig some digging around in the greenbacks.

cold start injector runs for 7.5s at -4F, less as temperature increases. after 95F contacts are closed in thermal time switch and no current flows to csi.

the aux air valve closes at 158F.

during cold start, lambda system sets dwell to 54 degrees after 5-10 seconds of running. That might explain why my cold idle takes a few beats to rise.

Today I drove the car about 20 minutes. after sitting for one hour, the car wouldn't start without the throttle open halfway. about 50 ambient, so definitely cold o2 = frequency valve enrichment, but probably less than 158F, so aux valve probably should have still been open. How it immediately cleared up once I cranked with opened throttle makes me wonder if it could be a mechanical issue like an injector not atomizing properly. I know the fuel pumps are good, the aux valve is good, the wur is good. Haven't tested the cold start injector or thermal time switch.

Did you have the injectors flushed? There was a Volvo tool for this purpose - highly unlikely your dealership has any tools that old though.

No, I don't think I ever took them out of this car. We actually do have the pressure test tool upstairs collecting dust next to a monotester. if thats the one you mean. I replaced the injectors in the 244 with new so I can take swap those over to test.

I replaced the o2 today and watched the lambda system while the car warmed up. The old sensor was Bosch, but had a crimp in the wire and a small sending element on it, so probably a universal. I replaced with Bosch 11032 from rock auto. Started with a nice high idle and dwell around 58. After about a minute it dropped to 20 static, then right away started to bounce and rise up to around 30 or so. within 2 or so minutes, which was surprising without a heated sensor. with the bad o2 it wouldn't move from 20 and didn't have any bounce. once the car was hot I adjusted dwell to 44 and set the idle to 900. I took it for a drive to get it properly hot and re-check idle, and It felt noticeably puncher taking off.

The problem is that it does not want to warm start. After the test drive I let the car sit for 10 minutes and it would barely run on re-start. It sputtered and stalled on a few attempts until I opened the throttle, then it roared up and came down to a normal idle. I cleaned the distributor rotor for ****s and giggles, maybe should check plugs if its been running lean this whole time, but doesn't seem that likely. I have a set of Bosch silvers I can put in, the o2 was very light. I'd really like to get it to behave properly. I had a good aftermarket fault tracing guide for k jet I need to dig out, the greenbook isn't being very helpful.

edit: the sending element was properly sized, but the cover was missing

Non-turbo K-Jet dwell should be between 51 and 59 degrees instead of 42-48 degrees, as per the greenbooks. So, it may still be off a bit. At idle, there should be a constant buzzing from the frequency valve as soon as the computer starts sampling the signal from the sensor. Is the Lambda-Sond system relay in decent shape and the correct part number with the blue "K" on top of said relay? BTW: protip: if you want decent condition Bosch K relays that aren't corroded/rusted to heck underneath, look in the 700/940 series cars with the fuse block and relay tray behind the ashtray assembly. They do use the relay for a different purpose. That way you don't have to use the aftermarket Kaehler relays that are now pretty much the only option new.

Ok, good to know, I'll adjust it. Yes, the frequency valve sounds good now. I'm not sure about the k jet relay, I'll have to look into that. Where is it located?

adamdrives said:

Ok, good to know, I'll adjust it. Yes, the frequency valve sounds good now. I'm not sure about the k jet relay, I'll have to look into that. Where is it located?

Click to expand...

Most likely next to the h/l relay on the inner fender, driver's side. K relay is double throw, if I recall correctly. There are newer Bosch plastic case versions that could be used

checked and it has a newer style plastic case relay. Think I put that in when I got the car on the advice of my ex-boss.

today cleaned and set the throttle body, checked the airflow meter plate and set dwell to swing between 50-60 at 900 or so rpm. everything was clean. Still has a warm start problem, although it seemed improved initially.

Messed around today with a halfhearted warm start diag. The rest pressure does drop to 0 after 15 minutes which is no bueno, but if I run the pump to 75 psi and then start it, the symptoms are about the same. It's significantly worse after about 30 minutes of sitting. it sounds like its running on 2 cylinders, then 3, then smoothes out and idles climbs up and falls to where it should be. I've read a couple threads of people having the same problem but no solutions. Have to think about how to proceed on that one. It's weird how the fuel pump relay needs pulse from the coil to ground, makes installing a non-intrusive manual switch more complicated. You need the lambda relay that mimics the coil pulse to send power to pin 85.

Determined that I have no reverse lights due to a bad switch on the trans, so I'll replace that when I have the trans out to do clutch and input shaft seal.

Rear defrost has never worked. No voltage drop between fuse and glass, ground good, but only consumes 20 or so mA when on. Tried running my own ground just in case, same results. High resistance in the heater grid? Common on older cars? I don't know if I'll bother replacing that glass after the ordeal I'm still going through with the windshield.

Cold starts are consistently improved. Idle is still somewhat erratic. Maybe just a symptom of the aux valve not being as precise as an IAC? It fluctuates between 800 to 1200 or so depending on how hot the car is. My 83 turbo idled perfect all the time no matter what.

Finally fixed the wiring to the windshield washer pump. Only took 3 years!

Oh, the joys of owning a 240

Miss mine, but soon the 242's gonna be all done and ready, can't wait

ADam

Still fighting hard warm starting. After sitting 15 minutes to 1 hour or so, It sounds like the car starts on one cylinder, and if it doesn't stall after a few moments begins running on two, then three, then finally all four. None of this happens on cold starts, just 4-5 cranks and then nice high idle.

Made a few observations today:

1. Rest pressure dropped from 30 psi to 0 in about 4 minutes.
2. The injectors are not leaking rest pressure.
3. With the pumps running, the injectors dribble out a little fuel. #1 the most, almost a fine spray.
4. When the pump first turns on, they all shoot out a little fuel
5. The cold start injector isn't leaking (or firing, but it might not be cold enough)

Since I have no rest pressure during warm or cold starting, the only meaningful difference is control pressure. Maybe no fuel in the system + leaned mixture is the culprit. The CI greenbook says that fuel pressure should be held indefinitely by the line pressure regulator in the FD, the check valve in the main pump, and the accumulator. I'll try blocking off the soft hose that feeds the main pump and see if pressure holds. If it doesn't, based on the greenbook illustration the only path back to the tank is past the line regulator in the FD. That seems the most likely as the accumulator isn't leaking and I replaced the main pump late last year. It is maintaining correct 70 psi line pressure however.