My 308GTS Nightmare

All factory tanks were aluminum. And they don’t have an internal filter, there’s no way to change it.
Fuel would seriously degrade a fiberglass tank in 6 months.

 

Injected 308’s have a filter in the LH tank outlet that feeds the pump part number 116870 don’t know if the carb cars have the same and as Kiwiokie said - unobtanium


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Letting a K-Jet sit unused is asking for problems. Run the motor at least once a week.

FV buzzing is trying to lean out the mixture. Unless you're really into emission controls, you can disconnect the FV connector, and run open loop.

The usual fault in a WUR is the clogged inlet screens. Multiple screens. The only way to get them clean is to take it completely apart, or else you wont get any cleaner through the screens. A clogged WUR will cause a lean mixture (high control pressure).

Backfiring is usually caused by a lean mixture. Can be a vacuum leak, or more likely the slits in the FD have become clogged (not enough fuel getting to the injectors).

Letting the car sit for long periods of time will dry the fuel out of the system, leaving behind a varnish that clogs the slits in the FD, filter screen at the inlet to the FD, WUR, and filter screens inside the injectors. Steel injectors will last forever, but they can get dirty, and get clogged filter screens. The fuel pump uses the fuel for lubrication. If the fuel is allowed to dry out, the pump will eventually rust, and seize, requiring replacement.

 

Nonsense. These cars get stored winters for 6 months or more with no problems.

 

Filter or screen? I agree there should be a metal screen thats not meant to be changed but rather flushed which requires removal of the tank in many cases. Had a few tanks out at one time or another.

 

First off, I am no expert on the closed loop (or anything for that matter), but my understanding is that if the frequency valve is disconnected, the mixture will go dangerously lean. A major adjustment in mixture at the CIS Unit would be needed to return the car to lambda. It is disconnecting the O2 sensor that puts the car open loop with the mixture staying at/near lambda (if the frequency valve is still operative). But again; I am no expert.

 

I think in your situation I'd be taking it to someone who knows what they are doing at this point. Appreciate that you want to do it yourself, but you've never really had the car running properly and sometimes it's better to know where your limits are and move on.

Either way, I hope it gets sorted soon and you get some enjoyment from it.

 

Yes, you do need someone trustworthy, but I'm sure someone here could recommend someone.

When I bought my car many years ago, I was lucky enough to meet someone who I was able to trust to do the job right and tell me the truth. It hasn't always been smooth going (the car broke a transfer gear a couple of months into my ownership, and as a result I discovered the diff had been rebuilt incorrectly), but it has been an experience.

 

That sounds promising and hopefully will solve the problem. The good bit is that once you get through all this aggro you'll have a car that you'll know is sorted and right.

 

To each his own. I've run my 3x8 K-Jet motor for some 30 years now, and done all the service myself. I can say unequivocally that 90% of the problems I've run into have been from letting the car sit unused. Also, many of the threads on these forums note problems popping up after letting the car sit unused.

 

Larry is a wealth of knowledge at CIS, he rebuilt my k-jet, airbox, et al.....and he will help troubleshoot over the phone....this is all he does in his shop, he is the Bosch k-jet expert

good luck

 

also...i highly recommend NEVER putting ethanol gas back in your car once the rebuilt injectors are installed

 

Disconnecting the FV connector will put the system into open loop. But you are correct in that there may need to be an adjustment of the mixture screw. These cars are adjusted lean from the factory for low emissions.

Also the buzzing FV is trying to richen the mixture, not lean it out. Sorry about that.

So it sounds like the OP has a lean condition. Clogged WUR, FD, injectors, or could be a vacuum leak. Also a faulty accumulator, but the OP has replaced that already.

 

When I got my 308 - back in the 90's... I always thought it was Fuel Injection... but almost always it was electrical. but the Check valve, and accumulators do go over time. if the system has been tampered with ... especially with those that don't know... its a mess. Kjet manuals cover 4 -6 cyl cars... not many on 8. not that it should be that much of an issue.

I don't recall connectors next to the oil cooler... but could be... have you checked your ignition wires and the extenders? there can be all sorts of funky running when the wires are cracked internally

if you un plug the Cat/ O2 sensor nothing really will happen, other than the "computer" does not hunt for a different ignition curve rich or lean mix- it gets set on just one. You can easily tell a 308 with a Cat and O2 Sensor working - at Idle it will pulse up and down 200- 150 RPM... when the systems are all new - its more like 100 - 80RPM... you can hear it, and the Tach will bob up and down slightly. the less the cat works - the more the hunting ... mine got so bad you could feel it on the highway like it was surging back and forth. I have mine un plugged and the connector covered with rubber nipples so they don't short on the chassis.

 

Yep - ideally you want to then set the CO ( how rich the mix is ) and leave it that way. a lot of guys go to the CO first... which is always a bad mistake. Checking for air leaks is also important - if you have original air hoses - they can be cracked and get larger as the engine warms up... I've had that pleasure as well.

 

I've seen the original plastic/nylon screen filter replaced with homemade brazed metal screens. The OEM is indeed NLA, and the filter has been on every tank I've ever taken apart from '76 to late 328's over the yrs. and unfortunately in every case they are all clogged or severely corroded away. An external in-line filter is a better option but requires a bit of re-plumbing to work. Or braze up a SS version. With ethanol in fuel now this only gets worse.

 

Like you, I've owned my QV for 33 years, since new. The only problems I have had, if you can call them that, are a miss because the Cavis wires broke internally, a replaced distributor cap (because I couldn't get the screws out to replace the wires), and a rusted 1 way valve in the air injection system. Brake pads have been replaced a couple of times, but other than that the mechanicals are original. I also do my fluids changes, but I leave the majors to a local shop. I will say starting it once a week for no reason is one of the worst things you can do to any car. If you are going to start it, drive it. That's not winter storage.

 

I can guarantee you're going to need a new accumulator. Of course if you're just letting it sit, you'll never know !

 

Here's my spring routine. Measure battery with a volt meter. (This year is was low as the battery was dying when I park it last fall and I had to charge it.) Connected battery. Get in. (At 71 that's getting to be the hard part.) Inserted key. Turned key. VOOM! Same thing it's done for the last 32 years. And hot starts are good regardless of how long it's been parked, 10 min, 1/2 hour, a couple of hours. So accumulator is fine, though I did have to tighten the banjo fitting a few years ago 'cause it was loosing pressure. Car starts, runs, idles and drive fine. You do yours, I'll do mine. I've treated at least a dozen cars this way and have yet to have a problem. And the 308 doesn't leak oil either, anywhere, and this set of cam seals is 8 years old. The first set lasted 25 years. I don't believe in fixing things that are broken.

New accumulator? When? Seems a lot of them have been replaced on other cars already. I guess I'm ahead of the game at this point.

But I'm curious, what does running the car have to do with the accumulator failing or not. You have gas, ethanol perhaps, in there one way or another. And if you start telling me about E10 separation problems I have a bottle of E10 sitting in my garage for the last 5 years with a little vent in the cap and the only thing that has happened is a little has evaporated.