New to DMC with sudden & multiple problems

[Shark Pilot]

Hey Folks,

I'l try NOT to be verbose, but I'm a SAAB guy entering into the long awaited DMC realm after 5 years of ownership, but not actually driving the darn car due to combat tours and renovation time.

History: Car purchased from AZ owner while in Iraq 2009. Shipped to Bauerle Automotive and refurbished over the next 4 years and two combat tours. Stage II upgrade, custom (annoyingly loud and catless) exhaust, remote doors and a host of other minor electrical and aesthetic upgrades as well as transmission rebuild. Car had 11,300 and now has 13,000 since I've been driving the crap out of it thanks to my SAAB Viggen being down for maintenance (repairs/upgrades).

1./ The car was driving like the bomb diggity and ALWAYS fired up within 2-3 seconds then one day within a week of taking it out of winter storage I turned it over, hot starting after a Home Depot run, and its run like CRAP ever since. Two weeks now. Starts hard ALWAYS now regardless of hot or cold, but reliably and reluctantly grumbles to life within 10 secs every time (though it sounds like arse). Likes to pause under load in each gear until I've revved it past 2800. Does it less when warm.

- Replaced ignition coil and wires with Pertronix 40kva coil, 8mm blue silicone wires, new K&N filter and "shielded" core wire from core to cap. I thought maybe my coil went and wasn't burning off fuel. This did nothing but allow for the car to start badly quicker. Not sure if that's good or bad as the problem is obviously NOT the ignition system.

- Brand new Bosch fuel injectors on the way and a new accumulator (both on my car are original) because of stuff I've read in these forums in terms of common failures and I pulled injectors 2&3 and they look like poo covered with rust/corrosion. I think the issue is fuel related, but whatever it is, it happened quickly. The car was working brilliantly, then 20 mins later the car just wouldn't run well at ALL and has been that way since.

2./ On the way to work this morning I experienced a sudden and violent uncommanded throttle accelleration shifting between 3rd and 4th gears. I saw 8000 rpm before I tapped the pedal and it decided to go back to idle. It scared the HELL out of me. What was that?? I've read the "sticky" and "sticking" throttle threads because I have idle issues too, but nobody has mentioned this weirdness. Ideas?

3./ Brakes violently vibrate when applied causing steering wheel shake and the car does NOT brake well. I'm assuming this is a warped rotor fault as the rotors are the original 32 year old ones. Ideas? Thinking of new rotors and pads all around.

I have more, but that's enough for now. I have scoured this forum (and the UK one) for days doing research, but I need some ideas on the engine and throttle faults that I have at least. Based on what I've read it could be one thing or another. Argh! I had a 1984 BMW 633, but this DMC-12 is like, arcane compared to that car so I'm a little out of my league here starting out with DIY. I will get it, but I hope you guys can help bend my learning curve a bit. I'm a UH-60 Blackhawk Test Pilot so I have the mechanical know-how and tools, but not the KNOWLEDGE as it relates to this model. Please help as it's been a little embarrassing for me to drive the car the way it performs/sounds: mallet:.

Patrick

[David T]

1) Could be a lot of things starting with the CPR to vacuum leaks to knocking a hose off of the vacuum advance solenoid.
2) I have to assume you have an automatic. There is no 4th gear. You have a sticking throttle and a problem withe the shift governor.
3) It can be only 1 bad/warped rotor and you may have some stuck pistons. How bad does the brake fluid look?

[Shark Pilot]

Actually I have a 5-speed hence the whole shifting thing, but I agree I was a bit nebulous there. The brake fluid I haven't checked because, well, I have no idea where it is. This seems silly I know since I was able to replace the entire ignition system with upgraded components and adjust the idle control myself, but like my post said, this car is new to me. The rotors are all original so I will start replacing the front rotors and pads.

An update on this post, as of yesterday, twice, my car fired right up on cold start. It hasn't done that since I picked it up from restoration and hasn't done it for the last week and a half, but I've done nothing yet other than the ignition stuff. I still have to get my injectors and fuel accumulator so I have to say WTF? Still doesn't run great, but it sounds and runs better, magically. I'm assuming this is just the beginning of this DMC adventure....

[Bitsyncmaster]

I had intermittent start (running). It turned out to be the connector on the distributor pickup wire was very corroded. I just cut the connector off and soldered the wires.

[dn010]

Years ago I bought the same coil, 8mm wires and +4 plugs. Then I started to have similar issues with not wanting to start and running bad. I put my original coil back in and my issues were resolved.

Secondly, with all the storage - did you have the fuel tank empty?

[NightFlyer]

Years ago I bought the same coil, 8mm wires and +4 plugs. Then I started to have similar issues with not wanting to start and running bad. I put my original coil back in and my issues were resolved.

Secondly, with all the storage - did you have the fuel tank empty?

+1 on swapping the OEM coil back in.

Did the OP happen to re-wire the resister grid at all when he installed the Petronix coil? If not, then a swap back would be simple and may prove revealing...

[DeLorean]

Interesting that you are a "saab guy" - I am one too. I have owned probably 15 over the years... You know of saabrally.com? I'd highly recommend it.

I'm not sure what your issues are, however it does seem pretty odd that the engine would rev up that high, as I thought the fuel pump relay has a cut off if it detects anything over 6800?

[Dangermouse]

I assume that the 8000 rpm came when you had the clutch depressed and you were changing to 4th. What sort of revs were you doing in 3rd just before you pushed in the clutch?

I wonder, if your throttle spool was stuck, would a sudden release if engine load allow the revs to jump up? Normally when you change gear, you let off on the gas as you put in the clutch.

I assume the pedal you tapped was the accelerator ? Did it move the cable enough to free the spool.

Far fetched suggestion I know, but that is an odd thing to happen. I assume it sounded like it was high revving so we can rule out a weird tachometer/gauge occurence

[Shark Pilot]

I find the whole "go back to original coil" thing unnerving since I spent $44 to get the darn thing here, install it and I'm "supposed" to see something happen. At this point the DMC geeks are rolling their eyes because yah, I'm THAT guy who believes what he reads. Alas, I'm new to this vehicle and so I am learning. Yes I kept the original resistor grid. Most of the previous owner's work to the car was performed by DMCH. In fact, ALL of it was and I have the records to prove it, but that grid is original. I could upgrade the resistor box, I just don't know what to buy or how to wire it. As far as the fuel cutoff, yeah I thought there was such a thing as well which is why it scared the heck out of me. Might not have reached 8 but 7.5 at least. Interestingly, ever since that nutty rev, the car has started well and doesn't run as crappy even after two starts with a 4 hour gap in between starts. Still waiting on the new injectors and fuel accumulator from Hervey as those are 32 years old and may be contributing to my fuel issues.

15 SAABS? Wow I thought I had a lot at 9 with 3 Viggens (on my 3rd Vig now a 1999 with 66k). Well thanks for the help. I'll post an update when I install those parts. We'll see...

[Shark Pilot]

I assume that the 8000 rpm came when you had the clutch depressed and you were changing to 4th. What sort of revs were you doing in 3rd just before you pushed in the clutch?

I wonder, if your throttle spool was stuck, would a sudden release if engine load allow the revs to jump up? Normally when you change gear, you let off on the gas as you put in the clutch.

I assume the pedal you tapped was the accelerator ? Did it move the cable enough to free the spool.

Far fetched suggestion I know, but that is an odd thing to happen. I assume it sounded like it was high revving so we can rule out a weird tachometer/gauge occurence

No dude it's not far fetched. In fact pretty much everything you described was right on. I was winding it out pretty hard in all previous gears and was at 5000 rpm, shifted to 4th and ZOOOOOOOOOMMM!!!! almost 8000 rpm. I instinctively went to neutral and tapped the accelerator because of my idle problems and after I adjusted the idle with my super corroded adjustment bolts I have to tap the gas to get rpm to go from 1500 to 1100 where I've set it. Pretty annoying actually, but the guy who upgraded/renovated the engine set it to 2000rpm which was just a no-go for me so I had to do something. Didn't need that despite the race cams. Anyway, it hasn't happened since, though now I operate with a fear that if I'm winding it hard again this might happen again. Indeed the throttle spool might have been stuck. I put WD-40 on it BEFORE I read the whole "Don't do that you idiot it's water displacement" thread. Now I think I just need to take it off, clean it, lube it and put it back on. Of course, I have NO IDEA how to do this and I don't want to F anything up. It's all right there and fairly intuitive me thinks, but I just haven't done it yet. Thanks for the response Dangermouse.

[Dangermouse]

So you were already in gear when the engine revved to 8k?

[Shark Pilot]

Years ago I bought the same coil, 8mm wires and +4 plugs. Then I started to have similar issues with not wanting to start and running bad. I put my original coil back in and my issues were resolved.

Secondly, with all the storage - did you have the fuel tank empty?

Dan,

Remember these issues started happening BEFORE I installed the Pertronix coil and things actually seemed to get BETTER after I installed the new coil and wires, just not running well like it was. The failure was sudden and continuous, almost like a vacuum line fell off, but all are snug. Also, I stored it with a full tank that had Fuel Stabil in it. The car actually ran really well every time I fired it up for a run around the neighborhood every 6 weeks or so. The problems only started happening when I started using it as a daily driver while my Viggen was down for maintenance and upgrades. Thus I am flummoxed...

[Shark Pilot]

So you were already in gear when the engine revved to 8k?

Negative. Switching BETWEEN gears. When I depressed the clutch she just let loose instead of winding down like it should.

[NightFlyer]

I find the whole "go back to original coil" thing unnerving since I spent $44 to get the darn thing here, install it and I'm "supposed" to see something happen. At this point the DMC geeks are rolling their eyes because yah, I'm THAT guy who believes what he reads. Alas, I'm new to this vehicle and so I am learning. Yes I kept the original resistor grid. Most of the previous owner's work to the car was performed by DMCH. In fact, ALL of it was and I have the records to prove it, but that grid is original. I could upgrade the resistor box, I just don't know what to buy or how to wire it. As far as the fuel cutoff, yeah I thought there was such a thing as well which is why it scared the heck out of me. Might not have reached 8 but 7.5 at least. Interestingly, ever since that nutty rev, the car has started well and doesn't run as crappy even after two starts with a 4 hour gap in between starts. Still waiting on the new injectors and fuel accumulator from Hervey as those are 32 years old and may be contributing to my fuel issues.

15 SAABS? Wow I thought I had a lot at 9 with 3 Viggens (on my 3rd Vig now a 1999 with 66k). Well thanks for the help. I'll post an update when I install those parts. We'll see...

I think I explained in the other thread that you started as to how you can test the accumulator for complete failure if you really wanted to. Unless the accumulator suffered a complete failure (rare), then there's no way that it would be causing what you're describing.

An unexplainable surge of power not caused by the throttle cable could potentially be caused by a malfunctioning CPR/WUR - more so the mechanical regulator side of it as opposed to the electrical warm-up side of it. I'm personally unaware as to a method of checking the CPR/WUR for proper operation, so perhaps someone else will chime in on this.

Other than that, check for vacuum leaks - while the car is idling, spray carb cleaner in spots around the engine and see if it causes an increase in idle RPM. If it does, then you know you have a leak and roughly where to look for it. Pay particular attention to where the idle air motor (CIS) runs into the lower mixture unit housing (aka 'the pipe of agony') and around the throttle body. If you do experience any leaks, then of course you'll want to identify and rectify them.

Best luck!

[Shark Pilot]

I think I explained in the other thread that you started as to how you can test the accumulator for complete failure if you really wanted to. Unless the accumulator suffered a complete failure (rare), then there's no way that it would be causing what you're describing.

An unexplainable surge of power not caused by the throttle cable could potentially be caused by a malfunctioning CPR/WUR - more so the mechanical regulator side of it as opposed to the electrical warm-up side of it. I'm personally unaware as to a method of checking the CPR/WUR for proper operation, so perhaps someone else will chime in on this.

Other than that, check for vacuum leaks - while the car is idling, spray carb cleaner in spots around the engine and see if it causes an increase in idle RPM. If it does, then you know you have a leak and roughly where to look for it. Pay particular attention to where the idle air motor (CIS) runs into the lower mixture unit housing (aka 'the pipe of agony') and around the throttle body. If you do experience any leaks, then of course you'll want to identify and rectify them.

Best luck!

I cancelled my order for the fuel accumulator. I haven't ever had any surges in power. The throttle stuck that one time between shifts probably due to a dirty spool. I've read your exact verbiage regading the carb cleaner in another post on this forum. I guess it can't hurt to try. While changing out my ignition system I got real intimate with the engine since at one point I was literally laying on it and I didn't see any vacuum leaks at all, but I will delve harder into this next week (wife will be gone so I can finally toy with it). Thanks for the help.

[Starglider]

DeLorean ignition systems are a minefield, lots of snake oil around, like the Nology HotWires that were snake oil and made the engine run worse. Even Ed Uding (who is an expert on the DMC-12 PRV) went through three different coil manufacturers building a reliable coil pack for my engine.

[Jonathan]

I know you mentioned your car having multiple problems suddenly and all at once, but perhaps trying to tackle them one at a time would make the troubleshooting easier? I'm having a hard time following what steps you have or haven't taken in trying to figure it all out or what the answers were to a number of questions about the car or recent history to fill in the blanks. It doesn't make it any easier for you, I know, when you have many different suggestions coming in from a number of different angles. The duplicate threads doesn't help either.

The car running poorly or not idling well and perhaps the sudden spike in RPMs could very well all be related, but not as likely for the braking system to be also part of it. I'd suggest focusing on one main issue at a time and getting it sorted out as opposed to trying to tackle many things at once. It'll potentially make it easier to figure out as you'll have less moving parts or things that got replaced and you left wondering what it was that made the problem go away.

[David T]

I know you mentioned your car having multiple problems suddenly and all at once, but perhaps trying to tackle them one at a time would make the troubleshooting easier? I'm having a hard time following what steps you have or haven't taken in trying to figure it all out or what the answers were to a number of questions about the car or recent history to fill in the blanks. It doesn't make it any easier for you, I know, when you have many different suggestions coming in from a number of different angles. The duplicate threads doesn't help either.

The car running poorly or not idling well and perhaps the sudden spike in RPMs could very well all be related, but not as likely for the braking system to be also part of it. I'd suggest focusing on one main issue at a time and getting it sorted out as opposed to trying to tackle many things at once. It'll potentially make it easier to figure out as you'll have less moving parts or things that got replaced and you left wondering what it was that made the problem go away.

Ok, now we know it is a 5-speed and the motor reved while you were changing gears. Sounds like you missed a shift and reved the motor. If the motor actually reved by itself (you said uncomanded) that is weird and I have no explanation. I would go over the throttle cable/linkage system and clean and lubricate it all as per the recall. Not having full control of the engine can be dangerous. I would also go over the shift linkage to make sure it is all properly lubricated and adjusted and replace any worn bushings.

[NightFlyer]

I've read your exact verbiage regading the carb cleaner in another post on this forum. I guess it can't hurt to try. While changing out my ignition system I got real intimate with the engine since at one point I was literally laying on it and I didn't see any vacuum leaks at all, but I will delve harder into this next week (wife will be gone so I can finally toy with it). Thanks for the help.

You're not looking for vacuum line leaks, but rather other vacuum leaks - such as the pipe of agony, an improperly sealed air induction / throttle body, improperly mated intake manifold, etc. Although the carb cleaner spray test can also assist in identifying routed line leaks as well.

[Shark Pilot]

You're not looking for vacuum line leaks, but rather other vacuum leaks - such as the pipe of agony, an improperly sealed air induction / throttle body, improperly mated intake manifold, etc. Although the carb cleaner spray test can also assist in identifying routed line leaks as well.

Interesting that you should mention the intake manifold being mated properly. I noticed the gasket that keeps the top half to the bottom half sort of crumbled when I had to take it apart to gain access to the distributor cap. Perhaps I need a new gasket there? Seems like that would be NOT the problem, but I suppose it couldn't hurt. I tried to put it all back and it seems to seat properly, but its such a crappy gasket seal and it looked dried out. I'll have to get some carb cleaner and deal with the test for leaks this week.

[DMCMW Dave]

Interesting that you should mention the intake manifold being mated properly. I noticed the gasket that keeps the top half to the bottom half sort of crumbled when I had to take it apart to gain access to the distributor cap. Perhaps I need a new gasket there? Seems like that would be NOT the problem, but I suppose it couldn't hurt. I tried to put it all back and it seems to seat properly, but its such a crappy gasket seal and it looked dried out. I'll have to get some carb cleaner and deal with the test for leaks this week.

You should never really have to take that apart. If you want to lift that unit up to get to the cap, take the W-pipe loose instead. A lot less trouble, fewer parts to drop, and cheaper gaskets.

[Trstno1]

I know this is a bit of an old thread, but did you ever conduct the carb cleaner test and what did you find?