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I think it?s Time for a Wagon 1988 740 Turbo

I had a few hours this evening so I took the wagon for a little run through a nearby curvy road even though it was like 95 degrees outside. Oh man what an improvement! Absolutely no clunks and everything felt so tight. It corners better than it has any right to. Here is a photo coming back towards our house:



I got back and wanted to give it a bath since it was really dusty from sitting in the garage with a bunch of dirty suspension work going on. After the wash, I went to pull it back in the garage but it wouldn’t event crank. After like 30 more min of sitting it fired right up like normal. As I was poking around under the hood the starter wires look a little oil soaked from when the PCV was clogged. I also noticed that the harness for the powerstage wasn’t fully clipped on. I’ve started it a handful of times since the no-crank (albeit with low under hood temps) and it seems fine. Any ideas? It picked a great spot to do this but I want to make sure the car is sorted before taking my daughter on the SLORolling drive in October.
 
Nice to hear that the IPD stuff is as rad as advertised- still loving this thread!

As far as the no-crank, I'm sure that someone who knows better than I will chime in, but I think your idea about the ignition power stage connector not being fully seated would make sense. Also, when was the last time you re-did the heatsink paste on that thing? I re-do mine periodically with Artic Silver paste as preventative maintenance and haven't had an issue since.
 
Car's looking great, sounds like it's a blast to drive too. 7/9s with some minor suspension mods handle surprisingly well. Enjoy!
 
Nice to hear that the IPD stuff is as rad as advertised- still loving this thread!

As far as the no-crank, I'm sure that someone who knows better than I will chime in, but I think your idea about the ignition power stage connector not being fully seated would make sense. Also, when was the last time you re-did the heatsink paste on that thing? I re-do mine periodically with Artic Silver paste as preventative maintenance and haven't had an issue since.

Yeah, that has probably never been done. I ordered a new one and some Arctic Silver last night. It's supposed to be hot again today so I will test it again this afternoon and see if fully connecting this power stage did the trick. If it did, great. I'll just slap some paste on it and keep the new one as a spare.

Car's looking great, sounds like it's a blast to drive too. 7/9s with some minor suspension mods handle surprisingly well. Enjoy!

Thank you! This is the first 700 I have had with the suspension fully sorted instead of just modified, amazing what a difference it makes. I'm growing up lol.
 
The car wouldn’t crank this morning after running a bunch of errands in the heat. After a few tries and shifting the car through the gears a few times it begrudgingly sprang to life. I’m thinking it must be the Neutral Safety Switch or Ignition switch. Since all the accessories seem to work well I was leaning towards NSS. It’s also a lot easier to get to the NSS than the ignition switch. This afternoon I pulled the console apart and sprayed some deoxit in the NSS. That seemed to flush a lot of crap out so I decided to pull the switch and then dissemble and fully clean it. Similar to the heated seat switches it looked like someone spilled a coffee in it as some point. I cleaned a bunch of tar-like substance off the contacts.

The new power stage arrived today so I installed that with some fresh thermal paste. Hopefully between these two fixes the car cranks and starts consistently in the heat so I can trust it to go on the SLORolling drive next weekend.
 
My daughter and I drove up to the Slorolling Rally this morning. The car did awesome over the 100 or so miles. We got to see a P1900, a bunch of Amazons and some clean 240s. Great day:


I think that performance earned it a new brass heater core... ugh
 
Been a while since the last update. The car was doing awesome since it’s trip to Los Alamos then this morning after running errands all morning it wouldn’t start for like 30 minutes until it cooled off. I parked it for the rest of the day and took my wife’s car to meet up with PCH and get the strut tower bar. He has a super clean looking wagon so it would have been great to see the cars together. I did a little painting and slapped the bar on this evening:


Yay!

Since I replaced the power stage and cleaned the NSS I am thinking the issue must be the starter or the ignition switch. Since it is a hot start issue that would lead me to believe the starter since it is subjected to under hood temps. Will do a little more poking around and then order a Bosch starter from FCP. Hopefully that clears it up so I don’t have to wonder every time I turn the key...
 
Been a while since the last update. The car was doing awesome since it?s trip to Los Alamos then this morning after running errands all morning it wouldn?t start for like 30 minutes until it cooled off. I parked it for the rest of the day and took my wife?s car to meet up with PCH and get the strut tower bar. He has a super clean looking wagon so it would have been great to see the cars together. I did a little painting and slapped the bar on this evening:


Yay!

Looks great!
 
New (rebuilt) Bosch starter arrived from FCP. I pulled the old one last night. It was annoying to get it out but clearly not the original unit so not sooo bad. I just finished installing the new starter. It sounds really good upon cold start but will have to drive it a bunch this weekend to see if the no-crank when heat-soaked condition persists. Fingers crossed. That old starter looked pretty oil soaked and unhappy. I should check the records to see how long ago it was done.


 
Forgot to add that during the install I must have knocked the DS front wheel speed sensor loose since the Antilock light is random on now... ugh
 
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It is a good feeling to bring a neglected brick back to a level where you can feel safe in it and trust it. I just got my 300k 1991 744 running today that I just bought. It felt great to get rid of the blown out junk and get a fresh cylinder head on there and get it running on all 4.


Try a voltage drop test. Here is a post I just made in another thread:


You could do voltage drop tests on the battery positive and negative cables:

1.Put a meter lead between the positive battery terminal POST. and the starter positive cable connection. Crank. You don't wanna see much more than 250 millivolts. (0.25V).

2. Repeat the test for the ground side. Meter lead between battery negative POST and a good ground on the block. Like the studs on the head.


If your readings are high, especially super high (3,4,10v+) you have bunk cables/connections.


CRANK and once the reading is stabilized and steady, THAT is your measurement.
 
Congrats on getting yours going! For sure it is a good feeling.

I’ll give the voltage drop test a shot in the next few days and see what it shows. Could the heat of the engine be enough to push a marginal cable over the failure point?
It is a good feeling to bring a neglected brick back to a level where you can feel safe in it and trust it. I just got my 300k 1991 744 running today that I just bought. It felt great to get rid of the blown out junk and get a fresh cylinder head on there and get it running on all 4.


Try a voltage drop test. Here is a post I just made in another thread:





CRANK and once the reading is stabilized and steady, THAT is your measurement.
 
Just found your thread. I also have a soft spot for the 7/9 Wagons. I owned a 92 745T which was one of the hardest vehicles to let go of ever..... it had stock wagon springs matched with BILS HD, and was a blast to drive. Those dampers are OE matched with full ride height and wagon springs. Ironically, the same wagon when our family got it, had the red progressive "lowering springs" and it drove horribly. It was a real eye opener for me that when the wagon went back to stock ride height, EVERYTHING got better!

You might not realize it, but when you lower these cars 1" or more you effectively destroy the front roll center. Likely yours is "hiding" behind those 25mm bars. What your wagon really needs (if you insist on keeping it lowered) is to restore the front roll center by installing the Kaplhenke QSRC kit. This change will restore the roll center to OEM..... and you won't believe the difference.

Folks want the "lowered look" for stance, Euro swag, etc...... I get that, but I would never accept the performance deterioration without correcting the front roll center. Actually all you need up front is the 24mm OE bar, stock rear bar (or no bar) and the QSRC with your lowering springs.

In my old age, I now appreciate the stock ride height and ability to take these wagons onto some gravel roads. If and when I buy another, I'll put it back to stock height and match up the factory springs with BILS HD.... it makes beautiful music together!

I'll keep an eye on your progress. Nice wagon!
 
Thanks for the kind words. I was looking at the QSRC kit when I was still thinking about going the coilover/really low route. After reading through Ben?s description it sounded like they weren?t really needed with the modest amount of lowering provided by the IPD springs.

Buttercup, my 72 142 was lowered to the point where you had to constantly think about how low the car was when driving. It also had very wide wheels squeezed onto it so fender rubbing was a concern over bumps and while turning. I decided that I didn?t want to lower the wagon to a height that would render it completely useless for actual driving so the springs seemed like a good choice.

Assuming the new starter fixed my intermittent no cranking issue and the voltage drop test doesn?t show any issues, the next item to repair will be the heater core. I just need to bite the bullet and get that over with. After that fun is over, I will order (and actually maybe I?ll order now since they are back-ordered) the QSRC kit since your post makes me very curious. Even if I could get away with not correcting the RC since the car is only lowered a little, if it will improve the handling I?ll give it a shot.

Just found your thread. I also have a soft spot for the 7/9 Wagons. I owned a 92 745T which was one of the hardest vehicles to let go of ever..... it had stock wagon springs matched with BILS HD, and was a blast to drive. Those dampers are OE matched with full ride height and wagon springs. Ironically, the same wagon when our family got it, had the red progressive "lowering springs" and it drove horribly. It was a real eye opener for me that when the wagon went back to stock ride height, EVERYTHING got better!

You might not realize it, but when you lower these cars 1" or more you effectively destroy the front roll center. Likely yours is "hiding" behind those 25mm bars. What your wagon really needs (if you insist on keeping it lowered) is to restore the front roll center by installing the Kaplhenke QSRC kit. This change will restore the roll center to OEM..... and you won't believe the difference.

Folks want the "lowered look" for stance, Euro swag, etc...... I get that, but I would never accept the performance deterioration without correcting the front roll center. Actually all you need up front is the 24mm OE bar, stock rear bar (or no bar) and the QSRC with your lowering springs.

In my old age, I now appreciate the stock ride height and ability to take these wagons onto some gravel roads. If and when I buy another, I'll put it back to stock height and match up the factory springs with BILS HD.... it makes beautiful music together!

I'll keep an eye on your progress. Nice wagon!
 
A couple months ago, I had an intermittent no crank issue that progressively got worse. Since I have the full wiring schematics for my 92 940, I root caused it at the shifter PRNDL safety lockout. Found NOS on eBay, installed (a bit of a PITA job to be honest) and have not had an issue since. Years back I put a factory BOSCH reman. starter on my 94 squirter engine, so I was fairly certain it wasn't that. I believe your year might use the same part safety switch. Insist on the OEM German made.... I wouldn't risk third world parts on such a critical component.

From what I remember in discussions with Ben, he said if the vehicle had been lowered more than 1.25 inches then the RC would be moved unfavorably. I have pics in my build thread that will show you what all is involved to fit the QSRC.

FWIW, the first set of lowering springs I ran in my sedan were the IPD blue sport springs. Over the years I ran both BILS HD and now KONI SPORT dampers. I'll say I have not missed the IPD springs one bit since selling them! The current progressives ride much better IMO than those "sport springs" did, which I had coupled with the BILS HD. By comparison, the 745T at wagon spring ride height rode brilliantly with them!

Good luck in sorting out your no start issue. Hopefully the set of contacts in the ignition switch in these cars is bulletproof.... I was dreading that was my high resistance / intermittent contact point, but it turned out to be the shifter safety switch.
 
I pulled that NSS switch out and pulled the switch apart to clean the heck out of the contacts so I?m thinking that isn?t the issue. I suppose it still could be faulty.

I found your QSRc thread. Thanks, that is super helpful. I?m sold!

A couple months ago, I had an intermittent no crank issue that progressively got worse. Since I have the full wiring schematics for my 92 940, I root caused it at the shifter PRNDL safety lockout. Found NOS on eBay, installed (a bit of a PITA job to be honest) and have not had an issue since. Years back I put a factory BOSCH reman. starter on my 94 squirter engine, so I was fairly certain it wasn't that. I believe your year might use the same part safety switch. Insist on the OEM German made.... I wouldn't risk third world parts on such a critical component.

From what I remember in discussions with Ben, he said if the vehicle had been lowered more than 1.25 inches then the RC would be moved unfavorably. I have pics in my build thread that will show you what all is involved to fit the QSRC.

FWIW, the first set of lowering springs I ran in my sedan were the IPD blue sport springs. Over the years I ran both BILS HD and now KONI SPORT dampers. I'll say I have not missed the IPD springs one bit since selling them! The current progressives ride much better IMO than those "sport springs" did, which I had coupled with the BILS HD. By comparison, the 745T at wagon spring ride height rode brilliantly with them!

Good luck in sorting out your no start issue. Hopefully the set of contacts in the ignition switch in these cars is bulletproof.... I was dreading that was my high resistance / intermittent contact point, but it turned out to be the shifter safety switch.
 
After much deliberation and stalling I finally ordered a new metal heater core from IPD this week. I figured pulling the dash apart would be the perfect opportunity to also pull the interior and finally do the deep cleaning the car really needs.

Here are the yucky rear carpets:

And the yucky front carpet:


Rogued is sending me driver’s side carpet since mine was completely thrashed.

I’ve seen worse looking foam but the underside was totally disgusting and black:




Starting to get better:


imghost

I shampooed and pressure washed the carpet today. It should be dry enough to put back in the car tomorrow. I pulled the foam and whatever that disgusting fiber was under the foam. Unless someone on here feels really strongly that I replace it with someone, I wont. It seems like nice weight and smell reduction to have it gone.

The new DS carpet and the IPD order should be here early next week!!! I’m getting excited for that heater core.
 
Please document the heater core job. I gotta pull the dash on my 1991 740 Turbo and fix a few things- noisy blower motor, leaking heater core, clogged evaporator drain, AND losing the dash vents on acceleration.

Did the starter fix the intermittent no-crank?
 
Please document the heater core job. I gotta pull the dash on my 1991 740 Turbo and fix a few things- noisy blower motor, leaking heater core, clogged evaporator drain, AND losing the dash vents on acceleration.

Did the starter fix the intermittent no-crank?

Okay I will!

I don?t want to jinx it but the starter seems to have done the trick. I drove it around all morning doing errands the other day and it was solid. Not as hot as it had been but I?ll take it.
 
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