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Just Some Dude in Jersey
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Discussion Starter · #1 ·
@#$%&! Don't Opel troubles ever stop?

A few weeks ago the car broke down coming back from a car show and I had to take The Ride of Shame home on a tow truck. I spent 5 hours waiting for a tow truck that never came and was hanging out in a furniture store and borrowing their phone to make calls until they closed and kicked me out whereupon I sat in the darkness on the side of the road for 2 hours, had a visit from a police officer, until a concerned young fella pulled over and gave me a ride home. More phone calls, 10 different towing companies, none answered their phones. Eventually the police officer got their township towing company, who normally only tow cars to the impound lot, to pick up my car and drop it off at my house at 10 o'clock at night. Argh.

The car was running pretty good, but I had noticed that the voltmeter only seemed to show 11 volts starting a few weeks earlier. Normally it would read a little over 13. But not all the time. That reading is my only clue to the problem. Okay, so, the car was running okay during the one hour ride to the show and 45 minutes of the ride home on the highway, but when I started having to stop at red lights during the last leg of the ride it started running crappy and I thought I heard rattley sounds coming from the engine. It got worse and worse at each red light, but at higher rpms between lights seemingly okay. Eventually it wouldn't start and run at all. Oh schitt. Studs unscrewing? Rocker nut unscrewed? Collapsed lifter?

The next day I pulled the valve cover and all was well. No loose rockers, lifters fine, oil getting to everything. Nope, it's not a valve issue. I think the tapping was just the irregular running of the engine.

I've done a LOT of cranking tests. Irregular sputtering with gaps of nothing. I've been focused on power because of the info my dash cluster is telling me. Run power on and it reads 11volts. Check everywhere else in the car and it reads 12.5-12.75. When I turn the key to crank the starter the needle dives to zero and the digital display screen says "6 VOLTS!", "10 VOLTS!", "9 VOLTS!", etc. I'll usually get a sputter at first crank, then nothing for 3-5 seconds, maybe a sputter, then nothing for another 5 seconds, then some sputtering that sounds like it will almost start, then nothing. Voltage everywhere in the engine compartment says 12.5 volts. The dash says 11 volts. I called RallyBob, he said change the battery. I have a spare! First I jumper cabled it to the car's battery. No improvement. Then I swapped out the battery and cranked. No improvement. I noticed only 12 volts at the coil while cranking, so I ran a jumper from the battery to the coil and cranked. No improvement. I removed the plugs, all are wet with gas, no oil. I put on a new dizzy cap. No luck.

RallyBob said it could be my alternator. I've got a one-wire one that works by magic. I'll need one for the new car, so I could buy another one and give it a try, but I don't think we're at that point yet. The sputtering seems like bad timing on a carbed car. But I've got Motronic FI.

And here's where this problem ends up getting dumped almost entirely in my lap. My car has 35 year old Motronic FI. It controls spark. Few of you have this system. I have an aftermarket fuse box and custom wiring throughout with no disconnects or harness connectors, everything is hard wired. I have an electronic dash cluster with a module that all your gauges and turn signals and stuff are hard wired to. I've got electric power steering with capacitors inside. And door poppers. And lots of other electric gizmos. 12 switches. Most of you guys don't have any of this stuff, so the usual Opel fixes and trouble shooting won't work. My wiring is VERY good, never a problem over the past 5 years.

About 5 weeks ago a support brace I installed on the alternator to stop it from vibrating broke. It was acting as my ground. That possibly caused an ensuing battery issue. I bought a fancy new charger that seemed to fix that problem. I put the 12 switches in back in Feb/Mar. Could a wire have come loose? Timing is locked down good and tight

Could the fuel injection computer be wonky?
Could I have some clogged fuel injectors? I had that problem due to sealer about a year ago, but I REALLY cleaned that sucker out and replaced all sorts of stuff.
Bad coil?
Bad crank position sensor?
Bad Idle air valve?

All sorts of stuff is on the table. Many things could be the cause of the problem. I'm trying to go for the most likely suspects, but I'm running out of them. Almost anything could be a cause. I'm on the verge of a wild goose chase.
 

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where is the dash system reading voltage from?
And 2 From what you have described, if your sure no more goob in the system It definitely is an electrical issue
And with the fuel being delivered and no fire I'm thinking it's in the ignition/firing system and not a fuel issue.
I remember you mentioning in another thread about wiring woes and bad connections through the plugs ( where the male or female gets loose, breaks or wolos out)?
Have you check for spark and is the cap good or pertronix or what ever you are using.
Hope I don't sound stupid but I don't know anything about motronic fi's
But it really sounds like a lost voltage or signal problem
 

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Simplify. I’d pull all the fuses except those that are necessary for the engine to run and then crank it.
 

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Detritus Maximus
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Gordon,
What US market cars used the same (or nearly) Motronic system?
The owners of those may have some insight.
 

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1970 Opel Gt - Purchased July 1972 - Chartreuse - restored - 3000 miles as of 02-16, 2021 -
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First Sounds like you are having a run of what I call - " its going to turn out to be something simple". So I will just repeat something someone told me when I recently had what kind of sounds like, a similar issue . The advice that I received was to is start with the basics/at the beginning, which is exactly what I did - I started at the battery, cleaned the terminals, took the terminals off the cables and discovered that the positive connection from the wire cable to the battery connector was in really badly corroded shape - I cut off about 1/2 inch of corroded copper wire and reconnected the connector to the wire and put it back on the positive terminal and bingo my problems went away. I like you was getting good voltage reading everywhere but when push came to shove the connection described above was not good enough to carry a strong 12 volts but would read 12 volts at the the battery, at the starter, at the fuse box, and every where else I checked. I was so happy with the advice and so happy that I started at the source and bingo, a problem quickly fixed. Good luck Gordon, you just never know...... If I had not have gotten lucky and checked that first, I may very well still be looking.........Best,
Carl
PS - regarding your question,"@#$%&! Don't Opel troubles ever stop? " , we all already know the answer to that question, don't we....
 

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Just Some Dude in Jersey
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Discussion Starter · #9 ·
System voltage everywhere in the engine compartment and one or two places on the fusebox that I checked is 12.5-12.75 volts. I DID read only 12.1 volts at the coil positive near the end of my testing while cranking. That's why I jumped power from the new battery to it. No change.
The car sputters and will sometimes sustain running for a few seconds as though only 2 cylinders are working. Or maybe 3, it's hard to tell. An unplugged or poorly connected injector plug. creates the same sort of miss symptom as a bad spark plug. I have not individually optically observed spark. My new plug wires have long boots and I don't think a spark would jump from them if I held the end of the boot near the block. I guess I could pull the plug boots and plug in a used spark plug and touch that to the block.
I wish it was easier to test the injectors' plug wires. The injectors are a strong candidate, because I previously had trouble with them staying plugged in. I have them heat resistant wire tied to keep them from working loose. It's a giant PIA, but my next experiment is to remove the whole fuel rail and injectors and rig a way to have them squirt at some paper to verify that they are all actually squirting.
I like Ken's idea of unplugging all the fuses except for the fuel pump and the coil fuse. The coil fuse wire turns on the FI through a relay. With only those 2 circuits intact it should run. Interesting bit: When I jumped power to the positive of the coil, with the key off, I could hear the FI relay engage and the fuel pump turn on. They are both on the ignition switched batch of circuits, so I guess I was backfeeding and supplying voltage to all the switched devices. Because I have a modern fuse box, I have a lot individual fuses for things that oem GT's don't have. If it works and the car runs, I can then plug the fuses back in one at a time until I plug in one that causes the problem.

In the next go-round, I'll try to do spark tests. Then I'll do the pull all the fuses idea. If no luck there I will do the fuel rail removal to inspect the injectors for clogs and test verify that they are all squirting.
 

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Just Some Dude in Jersey
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Discussion Starter · #10 ·
Do you have a ground wire from the alternator's body to the block? Metal to metal with no rubber absorbers in the path.
Yes, I added that back the other day. I had been using an F-bracket as an alternator stabilizer and ground and it worked just fine until it broke about 6 weeks ago. So I made a new one out of aluminum. Just to rule out grounding of the alt, I added the original ground strap back to it. I could take it a step further and remove the bracket and only leave the ground strap, as it was months ago before this trouble started.

I've been trying to follow the mantra: "What was the last thing you messed with?". I messed with a few things this year:

1) I bought 12 new switches and installed them.
2) New steering wheel and horn button.
3) Added some wiring for the other LED steering wheel.
4) My radiator fan shroud broke loose and tore up my THREE thermostats' wiring.
5) The alternator bracket thing
6) New stereo and wiring scenario

Most of those things were done months ago with no issues.
 

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Über Genius
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Bad coil.
 

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You did draw a diagram to help you troubleshoot the gremlins that were going to arise didn't you? Everything seems pretty straight forward following what you posted. It's going to be something simple. It seems like it's a ground.
 

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Über Genius
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You did draw a diagram to help you troubleshoot the gremlins that were going to arise didn't you? Everything seems pretty straight forward following what you posted. It's going to be something simple. It seems like it's a ground.
There's a voltage drop at the coil. Assuming he's using the same ground point for all his tests, the coil voltage drop indicates a short.

If you look up a voltage dividing circuit, you'd see how a coil acts as a resistor, dividing the voltage it's supplied.
 

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Hi, Just got off the phone from my psychic who helps me find my remote when it gets under the seat cushions and she says bad earths battery - body - block , body - alternator and fuse box and dash, maybe block gear box.
Seriously just because there is a cable doesn't it's a good earth.
Good earths are a must., I had a VW always good for me, always left my wife stuck and after much hair pulling turned out I was starting it with my foot on the clutch, and she started in neutral with no clutch, the clutch cable was a better earth than the earth strap new earth cable fixed after months and it was then sold the damage was done.
A friend of mine had a Rx3 Mazda which would start back out of the drive way then nothing , An earth problem which came good only when reverse switch was connected and switched on.
Also maybe coil or combo of earth issue and coil My GT needed a additional earth to the alternator.
This is my gut feeling.
 

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Buy or rent from an auto parts store a "Noid light". It plugs into the injector plug and lights up when it fires.
When you eliminated the excess wires from the harness, did you go all the way back to the ECU plug? The "Check Engine" setup I have with my Motronic is a huge help with troubleshooting. It's just an LED and a rocker switch. Light comes on, flip the rocker, and the code flashes. It took 2 minutes to id a bad TPS.
 

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This is similar to the 2 year search for a serious miss in my car that turned out to be the edis ignition module. I also agree with the "ground the alternator with a good ground strap" but it sounds like you did that. So it could be the motronic ecu that is the culprit. Do you have a spare that you can plug in?
 
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Just Some Dude in Jersey
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Discussion Starter · #17 ·
Okay I just made a video. Apparently, I must've drained the battery in the car, 'cuz my start test didn't last long before cranking crapped out. I had had my spare battery sitting on the radiator with the car's cables attached to it and the battery in the car still in place and disconnected. I was charging the spare battery overnight, but not the one in the car. I started out today reconnecting the battery in the car because the spare didn't change anything yesterday. Then I made the video........with a poor battery.

I noticed 2 additional lights came on on the dash while cranking that I never saw before. Probably indicators that my battery was weak. Well, that was enough for me, Bob suggested a new battery and I have a freakishly long history of my Opels eating batteries, so I went out to the store and bought a new one.

While I was out I thought I would have a very slow leak on one of the tires of the used Ford Escape I bought earlier this year. They told me that, yeah, they could fix it but that tire was from 2001 and another was from 2002 and all 4 were showing signs of rot. Holy Cow! My 2008 car had tires that were 7 years older than the car! All 4 tires were a different brand when I got it. The car was all scratched up on the right side and I figured the car must have gone off the road, had cheap new tires put on, and then offered up for sale. So, I ended up having to drop $700 for 4 new tires and an alignment.

I'll put the new battery in tomorrow. Here's the video. Watch the digital display say that I'm at 8v.....7v.......6v...while cranking:

 

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Not enough juice to run pretty much anything. The voltage drops off the instant you begin to crank. Swap out the battery for sure.
 

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ended up having to drop $700 for 4 new tires and an alignment.
I think we all will feel better knowing your on new tires.
If it makes you feel any better ( probably not) I just replaced 4, 20" cooper discoveries on the ole Dakota I'm giving my youngest son $1200.00
The maddening part of it is I replaced the same tires in 2013 that only had 500 miles on them :mad: But were dry enough that know way was I putting him behind the wheel with those tires on it.
The first hint of rain and you are slipping
 
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