Opel GT Forum banner

81 - 100 of 571 Posts

·
Bikini Inspector
Joined
·
5,769 Posts
what about if you just shift into neutral?

I wonder if vacuum line going to trans can cause this. Bad Vacuum Modulator?

I see setting the timing with a light and advance knobby. in your future
 

·
Member
Joined
·
1,502 Posts
Could you connect your timing light to your ignition coil wire and watch the light and give me details (does light dim etc.) and retest with car under load. Next connect to each spark plug wire one-at-a time to test and give me the results.
John
 

·
Registered
Joined
·
2,547 Posts
DAMMIT!

DAMMIT! DAMMIT! DAMMIT!

After work I needed to shift cars around to put the GT in a position to go to a car show in Philly as a first test of whether it will act up on a drive longer than 20 minutes. I didn't like the way it idled. Too fast with missing or hiccups or something. I took a quick 3 mile spin around the local river, then had to floor it to get on a highway at one end of it. I had predetonation. Okay, retard the timing a bit. The car ran like crapp as though only 2 cylinders were working. Idle sounded okay to the untrained ear, put it in gear and the idle dropped in half and the engine sounded like I was running on 2 cylinders.

One week till Carlisle.

How could my car go to heck in a hand basket one week after that great car show I won a month ago?

The only difference was that I topped my tank off at an unknown gas station. I'm now thinking that I must have gotten one heck of a bad batch of gas. The only fix I can think of is to pump out all 7.5 gallons of gas remaining in the tank and start over with all new gas from a known good gas station. Schitt, what the heck am I gonna do with 7.5 gallons of bad gas in buckets?

I am really, REALLY, pissed off now.

:cussing:
Hmmm! Clean parts?? ..................................................:eek:uttahere

Doug
 

·
Registered
Joined
·
1,671 Posts
A check on the 'net for "severe engine vibration when car is put into drive" comes up with broken engine and/or transmission mounts. And that is a pretty severe engine vibration. And quite a low idle speed when put into gear.

Do as Guyopel suggested, but then go and look at your mounts and verify they are intact. That means removing and inspecting carefully.

Broken throttle linkage...... is that due to the engine dancing about when it is in drive? Or inferior linkage parts?

Norbert raises a good point as well, but internally is the last place you want to be going for now. For this discussion, we can assume you torqued the flywheel and flex plate (or whatever Opel uses there) to factory torque specs, right? :thinking:

What's the quantity and Quality of the transmission oil look like on the stick? On a clean towel and wiping the oil on that stick, are there any metal fragments???

Really hate to suggest anything regarding the motor/transmission mounts when you first suspected you had a bad gas problem. For future reference, there is a little bottle that can be cheaply bought off ebay that can check to see if there is too much ethanol in your gasoline. It's an easy enough test. Cheaper yet is taking a clear glass jar and a sample of the original fuel, swirling it around and looking for any water droplets forming and settling on the bottom of the jar (water being heavier then gas). Just as well, you can probably see if any water has collected on the bottom of those buckets. These days, I don't think we have a problem with contaminated gas anymore, like we may have 40 years ago.

I remember having a question about the use of a harmonic balancer up front (or you not employing one); it's in that GTX thread which is too long for me to look (I did try); just as well as I don't want you going off on a wild goose chase right now.....and I can stand to be corrected on this matter, but if the motor requires a balancer, one needs to be on the front of that crankshaft. But that's a horse for another time as you do have some miles on this car since that issue popped up. Good luck; lotta words to digest here and I figure you'll just glance over this all a little bit.....

Lettuce know what you find.
 

·
Registered
Joined
·
1,671 Posts
Oh, the reason to check for ethanol? Sometimes the refiner puts too much ethanol (over 10%) into our gas. And unfortunately, the Opel is not a Flex-Fuel rated vehicle. So the car will run bad; if at all.
 

·
Registered
Joined
·
73 Posts
Norberts observation was very important. The sound and the way the engine is shaking are odd. As he said, check and make sure your flex plate is bolted on properly and not damaged.
I know a guy with an Ascona that also has an automatic transmission. He swapped engines and didn't realize one of the flex plate bolts is different and put it in the wrong place. Flex plate came loose and his engine started making noise/bucking like a wild horse.
There's a small inspection window at the bottom of the TH 180 housing, I'd take a peek.
 
Joined
·
4,231 Posts
To use the paper 1.9 flywheel behind a 2.4 is not the best solution.I have see a more then one of loose screws and cracks.
My GT have 950 rpm at idle and in drive postion 600 rpm with the stock 1.9 engine.
Check also all engine and transmission brackets as wrote above.
You also play with the timing from the ignition??
 

·
Senior Contributor
Joined
·
4,879 Posts
I agree with others that this appears to be a tranny problem. Adding a small amount of load to the engine when putting the car into drive would not cause the kind of behavior you are getting.
 

·
Just Some Dude in Jersey
Joined
·
13,779 Posts
Discussion Starter #91
Oh my, so many things to check. I'll look into everything you guys have mentioned, as well as, additional suggestions from Facebook.

One of the other ideas mentioned was from RallyBob who suggested a different type of diz cap and a resistorless rotor. He said that the Bosch ones failed under racing conditions. I'll try to get that type he mentioned today, but likely I will have to get a generic one, maybe even a Bosch(I have 2 Bosch rotor and cap combos ordered from OGTS as we speak), and I can see if that has any effect.

Let's look at recent things I have done to the car before and after the problem started happening:

New Carter fuel pump last Fall
LED engine compartment lights
3rd brake light
Installed a new Pertronix 3 and matching coil
Drove 100mph for a half an hour straight
Possibly got bad gas

I doubt that the lighting additions are the cause. The Pertronix was installed to fix the problem, so it's unlikely to be the cause of the problem. I flushed out all the gas and replaced with new gas from a known good gas station(Conoco).

That leaves the 100mph run and the fuel pump install.

I suppose that the sustained, high rpm, 100mph adventure could have fried something or caused something to vibrate loose.

Interesting thing: When I was pumping out the gas into the buckets I saw a sustained flow of bubbles coming out of the rubber hose as it was submerged in the fuel. I had removed the fuel line from my carb and slid a 2 foot long piece of metal tubing into the hose and clamped it to extend the hose past the fender, then I just slid another length of hose onto the other end of the tubing and into the bucket. I did not clamp it. When I noticed the bubbles I fiddled with that slid on connection, which was pretty tight, while my neighbor observed the bubbles and he didn't notice any change in the bubbles. I don't recall seeing the bubbles when I first stated the process, they seemed to start happening later. I wrote it off as air getting into the hose where I slid the hose onto the tubing. But now I'm thinking that maybe my connections at the new fuel pump may have settled in and loosened and that air might be getting sucked in at one of them. Then there is the see-through plastic fuel filter back there. What if a rock hit it and fractured it a bit and air was getting sucked in there. I tried jacking up the car back there to observe it while it was running yesterday but I couldn't get a good view of it.

So I need to put the car up on the lift to check that and the tranny bolts and other things mentioned. Oy. I've got cars all over my backyard and in the driveway and they're all in the wrong place and I need to move and shuffle all of them around........
 

·
Just Some Dude in Jersey
Joined
·
13,779 Posts
Discussion Starter #93
Regarding linkage ball joints: Replace both ends with 6 mm heim joints, they will last forever. Available from McMAster Carr P/N 2988K32, overnight delivery.
The lock nut had vibrated loose on the removable ball stud and the stud was spinning and the stud was probably cocking at an angle until it finally snapped off. I can't see that as the cause of the running problem, I would have lost all throttle control. Rather, it was a victim of the rough running engine and chose my driveway as the place to snap off. I have replacements and I may have one tack welded to the lever arm to prevent the unscrewing from happening again. I had considered heim joints when I made it, but I couldn't find a combo short enough.
 

·
Bikini Inspector
Joined
·
5,769 Posts
too far advanced. adjust timing and manually raise idle. something else is causing massive rpm drop. cap, plugs,rotor is a good place to start but something is goofy.

Dizzy came loose during trip?
 

·
Vendor
Joined
·
2,406 Posts
I just re-watched the video. The cars runs normally when in park (and presumably N?) but all hell breaks loose when you put it
into drive. Seems like it almost has to be transmission related (as stated by others) That's where I would start for sure. I can't understand how it
could be fuel or spark, when it revs so strongly in park.
Good luck, Gordon!
 

·
Registered
Joined
·
503 Posts
Have you checked the mechanical advance ? If the plate gets stuck, the car will lose power and die when you let go off the gas. It happened to me when I was driving to work with our Chevette, I was driving 130km/h on the motorway when the car suddenly started to run bad and lose speed and died every time I let go off the gas.
 

·
Über Genius
Joined
·
8,748 Posts
Something I learned on the Pertronix is that the magnetic rotor can sometimes not align with the pick up unit.
Also, on one, I had to move the pickup ridiculously close to the magnetic rotor. You might want to check those two things.

I designed and printed a better rotor for these conditions but the plastic I used is biodegradable so it's not fit to send to anyone. Someday I'll print a bunch in ABS and offer them as a substitute.
 
81 - 100 of 571 Posts
Top