Strayvette

Ok, here we go. Let the fun begin.
I pushed the 89 outside and put the top down to air out. When it was time to put it back in, it wouldn't crank. Security on, then no security light when turning the key to the start position. No horn. Interior lights are always on (even when the car is running). I disconnect the battery most of the time to save the battery from the lights, and for fear of fire. Followed the procedure for disarming the security system as per the manual.
Bypassed the vats behind the console. (Didn't find any fuses in there?) Starter now works, has spark, fuel rail pressure good, but no injectors. Tested injectors. Found one 8.8 ohms, one 12.6 ohms and the rest close to 16.8. Disconnected the two bad injectors, thought they were shorting the rest. No help.
Cleaned fuse connection (each fuse), along with every other connection that I ran across. Used wd40 on the door key tumblers, and "door switch buttons".
Time to craw under the dash. The key resistance read 4641 ohms at the connector under the dash. The second key read (an intermittent) 4740.
Break out the 1970's "Science Fair 150-in-one electronic project kit". Played a few minutes....hours...with resistance combinations, and unlocking the doors with the key. Key #1 plus 100 ohms added at the connector made the lights on the dash do something different. Disconnect, and reconnect the battery again, unlock the doors with the key again (whether it needs it or not), and the security light now blinks. The security light goes solid when IT STARTED (on 6 cylinders). Security light blinks while the engine is running. Security light blinks for at least 45 minutes after the key is out (I then disconnected the battery).
Now, what did I do to fix this? When will this happen again? What tools should I carry with me when I go for a cruse? Is it time for injectors, or a carb?
And oh yea...the horn now works.

aklim

https://fuelinjectorconnection.com/c...d-rail-o-rings

That will help you with the injectors. While you are there, replace the Fuel Pressure Regulator.

Take apart the TB by removing it, removing the IAC, IAC housing and spray all passages with brake cleaner. Also ask Jon for some gaskets.

Kevova

Pushed outside? The security light flashing relates to content theft deterrent. Do you have factory service manuals?

Strayvette

It appears that you are leaning toward injectors, not carb. Me too. I'm just really disappointed that after all these years, we still need an overly complicated devise to disable an overly complicated devise. A few drops of mouse urine can disable the car.

Strayvette

Pushed...you had to be there. Just a courtesy to the events that were taking place at the time.
I do not have a service manual.... yet. I plan on ordering one tonight.

aklim

You ohmed the injectors and some are bad. Only one choice left for them. You see, they were NOT designed for ethanol fuel hence the coils were fuel cooled and the ethanol or whatever snake oils they put in to clean things mess up the insulation on the coils, or so it was explained.

You want it simple, cheap and works well. That is fantasy land. Can you use a carb? Absolutely. Will it work, under all circumstances, as well as fuel injected? Absolutely NOT. If I lived in a cave, how simple would it be? No lawn to mow, no shingles that go bad, no plumbing, and hence a pot to **** in, etc. You wanna? I traded in an ATV for a newer one. Everything the same except it was fuel injected. Now I go anywhere, be it sea level or 10000 feet, I just drive. No adjustment of jets, no popping, etc. Sure, that raises complexity but I don't have to choke it, warm it, etc. You are typing this message with computers and not having to deliver it personally due to technology.

OTOH, maybe it's me. I'm skeptical of things but I prefer the solution to a problem to come from tomorrow as opposed to yesterday. I have no sense of nostalgia so a C1 or any other antique is only good to me for how much money it can fetch at sale time.

Strayvette

aklim:

You answered a few questions that I had. How new injectors are holding up to modern fuel...how long do injectors last?

I'm with ya on the technology, I'm that guy who puts electronic ignition on my 1978 motorcycle. No more points.
In this case, I don't see a cost effective upgrade for the injector system. Some look interesting, but expensive.
Carburation takes the most fun part of this car away...low end torque.

If I was worried about theft, I would install a gps device. The security in this vehicle will be desensitized. There are too many components. They are all old. Eventually I'l lose, and be stuck.

Kevova

Since you have 2 injectors that didn't ohm out ok. Cleaning won't correct faulty ohm readings. Figure on replacing them as Aklim suggested. You have spark fuel pressure but no pulse. Codes? Take a 12v test light attach clamp to positive battery terminal. Disconnect 4 wire est connector at distributor. Touch probe of test light to purple wire of 4 wire connector on the harness side. With the key on when probe is removed from terminal the injectors should cycle( clicking). If this happens ignition module is likely cause. If not, wiring or ecm. Because of how different things stopped working you should verify ground circuits.

aklim

The non-Multec ones don't have the fuel cool the coils so there is no insulation to eat up. A huge advantage, IMO is that I can take my car for a drive and not worry where I get gas which has no ethanol. In my town area, there are 2 spots. One is the airport and the other is the shop about 20 mins north of me, which is an area I don't go to hardly. So it is a PITA to have to go there to gas up. Rather than do that, I changed the injectors so I can pump when I am on "Empty" wherever there is gas. No, it is an old wives tale that you burn out the pump if you don't have half or quarter tank. I send it to FIC for cleaning and testing every 3 years or so because I have tested their work and know that there is an increased flow back to stock specs after cleaning. I have a friend with a bench at his workplace but not cleaner so I check out FIC to make sure that they are giving me accurate "before and after" readings. I have the newer ones on cars with over 200K so there it is. I would send them in for cleaning and testing or just get a reman set every so often depending on what stock FIC has at that moment of 42pph injectors.

I just try avoid older tech. All my ATVs, Jetskis and trike is fuel injected. Unfortunately, it isn't cost effective for lawn equipment to be FI yet. If you want to upgrade, you are going to have to get something in the self tuning area which is a waste if you are not using that function.

I'm not sure but couldn't you are losing much torque with either carb or EFI. Maybe the difference between a wet or dry manifold? Either way, I would never keep a carbureted car for myself. I want all the modern toys like heated seats (wife prefers), AC system that can be "set it and forget it", memory seats, etc.

Not worried about theft. The C4 hasn't touched the top stolen cars for a long time. Besides, why should I spend money on trying to find it back? I'm only out my deductible and it isn't that valuable. Take the check and buy something newer. And after they have trashed it, why would I want it back? IF, for whatever reason (and I don't) I want to rebuild something like that, I already know the formula so it isn't that bad.

At which point, buy something newer. Less trips to the dealership and have to hear "OBSOLETE", "NLA", etc. Less having to wait for a part on eBay that might be barely better than what you broke.

aklim

In addition, I'd check the fuel injector fuses to make sure that the bad injectors didn't blow them.

TheBlaster9001

Sounds to me like there's an issue with VATs. Was the battery at 12 volts? How old is it? I imagine you've already checked that since its easy and you seem capable of diagnosing electrical stuff. I think that VATs will disable the horn when it is going off, but since your alarm didn't go off, I further suspect the VATs module/circuit. That's odd that it was able to crank, but have no injectors when VATs was bypassed. How did you verify that the injectors weren't going? Could it have been no fuel pressure? Did the security light blink after the door was closed? Mine stops when the door closes, could your door switches be goofy?

Strayvette

Everything works except the injectors ( no noid flash) when I bypass the VATS module (above the radio). When I plugged the module back in, the starter didn't work. After I gave proper resistance from the key, and fiddled with the door locks, It started.

My security light is always blinking (except when the engine is cranking). I can't make the horn sound in alarm. Still cleaning grounds.
I agree that the door switches are a problem, but should a faulty door switch require a tow truck?

Strayvette

Grounds are "the" issue. Almost every connection in the cab is corroded. I was prepared for "Radio and Beer time" cleaning grounds when I got the car. I use dielectric grease on most connections as I go.
The car is now running. It starts without the vat bypass under the cash. I will be installing a resistor to save the key problem.

TheBlaster9001

It shouldn't, but GM didn't have any idea how these alarm systems would hold up (or break down, in this case) when they put them in cars. Part of my love for C4s is because they were experimental in many ways, but that can also be a big drawback. Complex modules that haven't been made for 20 years, that aren't serviceable create problems.

I forgot that your car has that silly paired key system, 85 does not. I would check out not only the ignition itself, but any other component that has to do with that part. Is there a relay for the ignition? Having the car not recognize the key would cause the no crank, and perhaps even with VATs bypassed, the 'foreign' key system keeps the fuel injector relay from working.

It almost seems like the VATs module is controlling the fuel injectors, is that the case? As in, when you bypass it, does the signal from the ECM not get to the injectors? That should be fairly easy to check out.

I suspect that the car needs VATs plugged in to fire the injectors, but isn't recognizing the key (or door switches), which is causing the intermittent no crank. On my girlfriend's 86, if you don't push the key in all the way, it won't crank (same silly resistor system).

Strayvette

Sorry guys,
I ended up with two threads of the same. I think I lost won in "drafts", the found it again and posted it by accident. Not sure what to do about that.

Strayvette

I think you are correct in all of your points. There are other threads that are very detailed on the subject. It's is crazy complicated. I am looking for that special place on a circuit board that a drop of solder will bypass all this stuff...Probably not going to happen.

Sorry guys,
I ended up with two threads of the same. I think I lost one in "drafts", then found it again and posted it by accident. Not sure what to do about that.