Hello everyone! This is my first post here and I need some advice! I swapped a 1991 Camaro 3.1 into my 1972 Opel Gt almost 17 years ago now and completed all the electrical work and integration myself (I'm an electrical engineer by the way). Drove the car for probably 6 years during the nice days and never had any issues. Then it just quit and would not start at all. Cranks but no fire. The car has sat for the last 10 years and I'm trying to get it back on the road.

So here's what I've done so far: tested resistance of the injectors and both banks read right at 4 to 4.5 ohms at the injector harness. With key in the on position I read 12 volts at the engine harness side (pink wires). When I connect a test light across the pink and blue or green wires on the engine harness side and crank the engine I get the blinking light. This tells me the ECM is pulsing the injectors. I've tried spraying starter fluid in the intake when cranking and the engine does run but quits when fluid is removed. Fuel pressure at the rail reads 45 psi using a gauge from the auto parts store.

All the above tells me everything is functioning as it should except the injectors are not spraying fuel. Am I missing something? One other note that is strange: If I try to read a code from the ECM I get nothing.....just a steady SES light. Any ideas would be greatly appreciated!

 

Are you sure you are doing the paperclip test correctly?

What does the gas smell like? Varnish???

Have any idea if it's sparking? How do the plugs look when you try starting it? Soaking wet it's not sparking or even the map could be overly flooding the car. Dry obviously it's not getting fuel. Keep in mind that the Icm controls both the spark and fuel. So sometimes if it's bad it may stop both.

Ohm the injectors at each individual clip. Hopefully your read no lower then 12.0 ohms. Measuring like you did shows the total resistance and since it's parallel wired it's the not showing you each individual injector. But they could be clogged if it's sat for a log time.

Does the gas in the tank smell lIke varnish? If so I'm sure your fueling system is clogged up bad and needs to be cleaned. New injectors or cleaning them, new fuel filter..exc. if you are seeing 45psi at the rail it's obvious it's getting to the injectors but they may be clogged up. Just like you suspect.

 

Yes I'm pretty sure I am doing the paperclip test correctly. That test grounds pin C3-E12 of the ECM to ground which is what I'm doing. Gas tank was drained, flushed and I have 3 gallons of fresh gas in the tank. I have run the fuel pump with the lines open to make sure any old gas was flushed. But recall I mentioned the engine quit just days after it ran fine....although that was 10 years ago. I do have spark at the plugs and the engine will run with starter fluid. Is it possible all 6 injectors could clog at once? Thanks!

 

Its possible but rare.. I had a problem like this with mine about 7 years ago as it sat for a good 5 years. Turned out to be clogged injectors. 4 of them. But at first it ran ok for a week then just died on me one day.

Contact southbay on here they will make you a great deal on a new set of them. Either way the stock ones are junk imo. The design is bad. If you wanted you could pull the injectors and apply a 12vdc signal to them to see if they open one at a time.

 

Thank you for th tips on the injectors. I had read a few posts mentioning poor OEM design. How can I contact southbay? I will probably pull the injectors this weekend and try the bench test. I'm actually hoping they don't work because that would at least assure me they are the problem!

 

Anyone know why the ALDL light test won't flash any codes? I am confident I'm grounding the correct pin from the ECM. Checked all connections with an ohm meter and looks good. Turn the ignition key to on and light just stays on...no flashing of code 12 or anything else.

 

What dose the CEL do without a paper clip when you turn the key on?

 

It comes on and stays on. Hard to tell but there might be a very quick flash and then stays solid. The flash might just be a voltage variant when the fuel pump comes on then off. Hard to tell.

 

If there's no flash, you're not running off the PROM, you're in Limp Home Mode. There should be a noticeable flash then on solid until the engine starts.

Check that the MEMCAL is seated in the ECM, and that nothing looks damaged on the MEMCAL or the ECM board.

 

That's awesome I had a 1975 Opel Manta which was Factory the electronic fuel-injected 1.9 liter with a stick and I was going to do a similar engine swap that would be awesome if you could post some pictures

 

Reseated the memcal but would have to take the case apart to inspect the ecm board for any obvious electronic failures. I did order a set of injectors from Southbay yesterday so can't wait to get those!


Here are a couple pics of my Opel GT.

 

Very nice Opel. Don't see those everyday.

 

Injectors might also need replacing but you need to find out why the ECM is in LHM before going any farther.

The swap looks good and clean.

 

Nice swap, keep us updated

 

Looking forward to the new injectors and hope that does the trick. What causes the ECM to revert to LHM?

 

Like I said, the MEMCAL itself could be an issue, or something wrong with the ECM itself.

 

Hi there,
My check engine light wouldn't light up either, when I first got it. the problem turned out to be a blown fuse for the ECM, in the Camaro it was the fuse by the battery, not in the fuse block. I don't know where it would be in your Opel. Nice swap and nice car!

 

Update!

Received new injectors from Southbay today and got them installed. Engine fired right up and appears to run fantastic! Hard to believe all 6 old injectors failed together but apparently so. Have lots to clean up on the electrical system and she should be ready to drive once again! Woohoo!

 

Like you said very strange all six would go bad at the same time I've never seen that happen before myself usually it'll be 1 maybe two at the most the time but the motor will still run it will just kind of have a misfire but none-the-less hell yeah

 

I am glad to hear you got it up and running. You remind me of mine when I had multiple injectors go bad at one time

 

alls it takes is one injector to short out to mess up the ecm , when they short out resistance goes low and the current draw of the injector goes up since its going to a dead short and not threw the coil inside the injector

if u really want to find out if any are shorted just use an ohm meter on each individual injector
without looking it up i belive the stock injectors should ohm out between 12.5 and 15 ohms each


very cool looking cars guys

 

Glad you got it worked out, cool swap and kind of neat thinking about one of our stock V6s being a performance upgrade. I would love a video of that thing driving if you could.

 

Thanks everyone. still cleaning up some wiring in the dash but hope to get it on the road this weekend or later this week. All old injectors passed the ohm test so that is strange. They must be all clogged or failed in some other fashion. Good news is since it is running the ECM must be good.

 

Just because the engine is running doesn't necessarily mean that the ECM is good...

Is the CEL on while it's running? Can you connect to it and see real time data?

Delco ECMs have a Limp Home Mode that in some cases can have the engine run well enough that it may seem to be running properly.

The fact that you say that the CEL doesn't flash at key one makes me think you may be in LHM.

 

Six Shooter, I think you are right. CEL light was initially off while running engine in the garage. Took it out for a drive around the block and started running rough and light is on.

If I do the paperclip test with the ALDL I still get no results....same as before. Light just blinks steady.....no code 12 or any other code. What does that mean?

 

Ok, I just disconnected the battery and removed and reseated the MEMCAL board. Engine started normal and no more CEL. Drove around the block and seems ok but I have a broken weld on the exhaust header that is rattling badly. Shut down, did the ALDL code check and it flashes code 12 correctly and no other codes. Just repeats the code 12. So based on these results I think reseating the MEMCAL must have cleared the LHM cycle.