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760 '87 760T no power, low rpm

Does your cat have missing honeycomb?

Forget the OEM or universal cat. Use the CARB website and figure out which cats with EO numbers are certified for use on your car. Don't ever stray from this!
A cheaper, but EO numbered cat will probably last you a few years and get you past smog a few times. Don't expect the world of it, but remember, you can can practically buy 2-3 Magnaflows for the price of an OEM.

Might want to quickly summarize what's transpired with your ride and what's wrong. Kinda hard to follow... Sounds like you have a leaking CBV. Look for a flat area (~1.5"x0.75") near the intake of the turbo. Might be covered in thick icky black crap. Should be an ID plate underneath if it's a Mitsubishi type turbo.
 
Odyssey reviewed

Thanks for the input, and yes, tis been a few months of this then that, starting with a new engine harness, which was "all it needs". NOT! Sorry, perhaps not quick.

Dave Barton's Dutch-sourced harness and support is awesome and reasonably priced, but after it was in, the car wouldn't start. Fuel pumps ran, but I found no spark at plugs. With guidance mostly from the FAQs, I changed the ignition module on the L inner underhood wall. Nope.

No fire from coil, so after two other coils and a complete bypass of any car control of it, a new coil got spark to the cap, but nothing out to the wires, despite those new cap/rotor parts. Plug wires looked excellent but new cap/rotor did the trick to start the car, but I found the warmed-up power to be dismal, with all other driving aspects quite good, IF seemingly low on boost and low vacuum.

Cooled turbo showed easy spinning and no detectable play.

The pro who knows this 765T said the AAM was dying, 'cause the engine quit when it was unplugged, despite voltage variance with varied airflow as I revved the engine. The replacement changed the running characteristics, but did not solve any other issues. He got it to backfire, which blew the brake booster elbow apart. That part was changed.

Only very minor vacuum leaks fixed after a pricey smoke check. Also fan clutch was reported weak. After a very warm indication a few days later, a new tropical Aisen went in. The car stills runs just above 1/2 gauge, but there is no more coolant loss.

R&R of intercooler and thorough degrease and flush removed very little crud, similar to what I found in an earlier boost hoses look for oil. Still no detectable boost escaping from those hoses which appear intact and firmly clamped.

Adjusted the wastegate arm, both ways, with no betterment in boost. Reviewing the old school vacuum troubleshooting chart had me check ignition timing, which seemed close to spec. Rotation to max, improved acceleration and vacuum with no pinging or knock. That sensor tested high resistance, and was cleaned prior to reinstall.

A pretest for smog, indicated the Calif, sticker, and probably a bad cat. As earlier stated, it rattled when slapped and a flashlight revealed comb material had partially melted and was mostly lying in pieces inside the housing, all removed, but that explained the normal temperature rise between its in/out pipes. There was some catalyst operation, but not enough to pass muster. I was unwilling to drill test holes fore/aft of the cat for pressure differential check.

The car drives quite well, otherwise. The amateur/hack aftermarket radio install by the PO is now done properly and the replacement "proper" Chinese power antenna does NOT fit a wagon, despite all eBay listings' assertions. I repaired someone's erroneous wiring of that switch and circuit and plan a new flat antenna.

Many red plastic interior parts fixed or replaced; power seat operation fixed.

I think the center driveshaft support has too much play; on the to-do list./ Also on that list is a proper redo of some vacuum lines, particularly the HVAC feed, which is now tied into the 1/2" hose between IAC and vac pump, leaving a capped intake port (noticed by the smog tech). There is a small leak somewhere in that circuit, either cruise control or underdash pedal 'switch' or HVAC actuator.

Mulling the value of ipd's (on sale) F/R sway bars, recalling the driving joy of an earlier 245 brick, so fitted.

Have no cat; will shop!
 
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Thanks for the input, and yes, tis been a few months of this then that, starting with a new engine harness, which was "all it needs". NOT! Sorry, perhaps not quick.

Dave Barton's Dutch-sourced harness and support is awesome and reasonably priced, but after it was in, the car wouldn't start. Fuel pumps ran, but I found no spark at plugs. With guidance mostly from the FAQs, I changed the ignition module on the L inner underhood wall. Nope.

No fire from coil, so after two other coils and a complete bypass of any car control of it, a new coil got spark to the cap, but nothing out to the wires, despite those new cap/rotor parts. Plug wires looked excellent but new cap/rotor did the trick to start the car, but I found the warmed-up power to be dismal, with all other driving aspects quite good, IF seemingly low on boost and low vacuum.

Cooled turbo showed easy spinning and no detectable play.

The pro who knows this 765T said the AAM was dying, 'cause the engine quit when it was unplugged, despite voltage variance with varied airflow as I revved the engine. The replacement changed the running characteristics, but did not solve any other issues. He got it to backfire, which blew the brake booster elbow apart. That part was changed.

Only very minor vacuum leaks fixed after a pricey smoke check. Also fan clutch was reported weak. After a very warm indication a few days later, a new tropical Aisen went in. The car stills runs just above 1/2 gauge, but there is no more coolant loss.

R&R of intercooler and thorough degrease and flush removed very little crud, similar to what I found in an earlier boost hoses look for oil. Still no detectable boost escaping from those hoses which appear intact and firmly clamped.

Adjusted the wastegate arm, both ways, with no betterment in boost. Reviewing the old school vacuum troubleshooting chart had me check ignition timing, which seemed close to spec. Rotation to max, improved acceleration and vacuum with no pinging or knock. That sensor tested high resistance, and was cleaned prior to reinstall.

A pretest for smog, indicated the Calif, sticker, and probably a bad cat. As earlier stated, it rattled when slapped and a flashlight revealed comb material had partially melted and was mostly lying in pieces inside the housing, all removed, but that explained the normal temperature rise between its in/out pipes. There was some catalyst operation, but not enough to pass muster. I was unwilling to drill test holes fore/aft of the cat for pressure differential check.

The car drives quite well, otherwise. The amateur/hack aftermarket radio install by the PO is now done properly and the replacement "proper" Chinese power antenna does NOT fit a wagon, despite all eBay listings' assertions. I repaired someone's erroneous wiring of that switch and circuit and plan a new flat antenna.

Many red plastic interior parts fixed or replaced; power seat operation fixed.

I think the center driveshaft support has too much play; on the to-do list./ Also on that list is a proper redo of some vacuum lines, particularly the HVAC feed, which is now tied into the 1/2" hose between IAC and vac pump, leaving a capped intake port (noticed by the smog tech). There is a small leak somewhere in that circuit, either cruise control or underdash pedal 'switch' or HVAC actuator.

Mulling the value of ipd's (on sale) F/R sway bars, recalling the driving joy of an earlier 245 brick, so fitted.

Have no cat; will shop!

In regard to the sway bars your 87 760 should have 21 mm front and 19 mm rear sway bars if it's a sedan. Leave the rear as is and swap in a 24 mm front bar and mounts from a 92-94 960 sedan.
 
1987 760 Turbo has 19 mm rear sway bar. Other sedans have 16 mm rear sway bar. 19 mm rear with a 24 mm front is plenty for my 88 765 Turbo.
 
Seems like you're not getting quality advice from your locals.

Forget bars, braces, upgrades, etc. Did you get the coil thing fixed?

As for the cat, just FYI, the Magnaflow EO numbered cat is not a drop in fit. I think it had 2 straight ends when i bought it. As i remember, the factory cat uses a sealing ring, thus requiring a bevel on the ends of the cat.
 
this just in

Seems like you're not getting quality advice from your locals.
Agreed; not a happy lesson.
Forget bars, braces, upgrades, etc. Did you get the coil thing fixed?
Not only that, I feel I got ahead of myself by ordering the cat from FCP, which won't even leave the supplier until 4/12. Then, the car was running rather well.

FYI, the Magnaflow EO numbered cat is not a drop in fit. I think it had 2 straight ends when i bought it. As i remember, the factory cat uses a sealing ring, thus requiring a bevel on the ends of the cat.
That's what the illustrations show and part of why I ordered the other. What appears an identical cat to the EO MagnaFlow, is half its price. That's pricey for an EO tag!

As for the 'coil' or whatever demon is tormenting me: I worked through the ignition section (again) of the pdf, 740 No Start. I can smell fuel with no spark.

In the course of the above, the coil, Power Module and ballast resistors were unplugged as directed. I could find neither a failure of any test nor any 100% agreement, but when I had all reconnected, the engine started! Say what? Okay, it ran for about 20 seconds, then died; would not restart. The only components not replaced are the Hall sensor, which those tests say operates the fuel pump via the relay, and the ECU.

It seems a reboot of something got it running, then slowly killed it. I pulled the ECU and can smell no 'burnt' aroma, but didn't open it, as if a visual will tell me more than a smell, except in the case of a huge failure.
Short answer: no, the 'coil' issue remains. I've briefly searched for a replacement, with many on that auction site, but few have any warranty.
 
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A concern I have is the attempt to regen the battery, boosts, etc. over three days. I may have seen a little over 16vdc on the charger, which may have damaged some electronics, but after it started that fear abated.

The PO stated the car would run for 20 minutes, then die, so that may still be an unfound and unaddressed issue..
 
One thing I forgot to mention. Your car may have a boost pressure over pressure switch. I had issues with my 88 765 Turbo that ended up being caused by poor connection at this switch. I thought the issue was the fuel pump relay, tried 3 different relays with same result. On my 88 765 this switch is located on or near the coolant reservoir.
 
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I wondered about that device some time ago, then got lost in the rest.

I looked and looked for that device, and only found it on the schematic, with blue and yellow-red wires as clues; not near the reservoir or where the Haybes shows it L-R engine compartment,either.

The only wires near the reservoir are test points. Grrrr.

I did find a shabby vacuum line near the turbo, going from the controller somewhere else down there. Gotta do some disassembly to see and change it. Crappy line might be why the boost was degrading. I need to redo, properly, another VAC line or two, that someone altered.

Then again, with no start it matters little, just yet.
 
I finally found where they're supposed to be. I have the LH pulled and ready to ship to Electronik Repair, in Mesa, AZ, along with two AMMs, for full testing and/or repair along with the EZK.
 
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Nicely buried above the pedals, aren't they. The pressure switch has no vacuum line attached. How to test it is my next search.

I found the trick to remove it in another thread: the one phillips screw right behind the steering column, then the whole metal mount slips out of other bracketry.
 
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Turbo with slushbox always feels really limp off the line to me, not having driven your car I can't really say if what you're describing is normal. The next thing I'd check is ignition timing and the timing belt. I got the belt off by one tooth on a car once and it had almost no power at low RPM, could barely even get the car moving but then it would take off like a rocket when the turbo finally spooled up.
 
If it hasn't been mentioned already, closely inspect the harmonic balancer. When they fail, the outer portion which also has the timing marks tends to spin on the inner portion and the result is the timing is not where you think it is. Pull the #1 spark plug and verify the engine is at TDC, then check that the timing mark aligns precisely with 0 degrees.
 
If it hasn't been mentioned already, closely inspect the harmonic balancer. When they fail, the outer portion which also has the timing marks tends to spin on the inner portion and the result is the timing is not where you think it is. Pull the #1 spark plug and verify the engine is at TDC, then check that the timing mark aligns precisely with 0 degrees.
Thanks. It was but I waited 'cause the engine is rather new, from Sweden. Now, that doesn't mean one heckuva lot, but..

With the brains enroute to AZ, I'll try to check this.

Some Saabs and some Porsche 928s used a very similar system, and the AZ shop primarily works on the latter. His reply to my query was friendly, which is a good start.
 
Wow, you're still actively fighting this.... You need to go to a JY and pluck some stuff... For the amount of time and effort you've put in, a fairly easily found lh2.2 740 could have given you a coil, dist, some "free" sensors, etc.

And.... EZKs and ECU's don't often go bad with these models. Probably not fighting the overboost switch and hitting fuel cut.
 
EZKs and ECU's don't often go bad with these models. Probably not fighting the overboost switch and hitting fuel cut.
Yeah, thanks. I should have the rebuilt parts back in a few days. Putting unknown, used parts complicates the troubleshooting, unless absolutely certain that they are good, which is why I made this move.

The intermittent, but seemingly heat-related problems are so hard to find.

Both AMMs are similar and off calibration about 20mv, but the tech says usually won't cause problems until >30mv.

He said:1) the fuel box was fine, but soldered every connection, to be sure, and 2) the ICU is rarely a problem, being well built. He did replace a few aging capacitors in it.

I'm going to check the Hall sensor wire, but the tach has always read properly.
 
The no power and low boost problems sound like a clogged/restrictive exhaust to me. Try driving on an open downpipe.
 
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