RTRx7

iTrader: (2)

Just classic right there.

Crit

iTrader: (6)

I'd start with removing the air filter, and consider borrowing Tim's Air/Fuel gauge. You can build a short length of wire to insert into the O2 sensor wire connector just on the firewall side of the fuel rail, and sense the output there for the gauge. If your mixture stays relatively consistent or runs a little rich, the air filter's clogged. If it runs lean, you're likely losing fuel pressure, whether from the fuel pump, filter, etc. If it looks good, then you may have a coil that can't keep up.

You're also welcome to borrow my fuel pressure gauge with a long hose, which allows you to sample the supply side at the hardline on the firewall, and just hold the gauge against the windshield with the wipers. No fuel in the cabin, and you can watch it under load as you drive around. If you want to drag the family up next weekend, I'll bring my tools with me.

There aren't many GSL-SE guys in the OGTA, so you may be better off posting in the first gen section for more ideas.

gsl-se addict

iTrader: (3)

I would check fuel 1st. Pressure and volume. Pressure should be ~28psi at idle and ~37 psi just after a hot start or if removing the vac line to the regulator so that it references atmospheric pressure instead of manifold.

For volume, remove the fuel feed at the firewall and stick it into a 1 gallon jug. Turn the key 'ON' and prop the AFM door open. Time for 1 minute. After 1 minute, the jug should be about 50% full. If it is much less, you likely have a clog somewhere in the fuel system. Start with the fuel filter and then move on to dropping the tank and checking the pickup screen and the pickup/return lines.

One car that I worked on was so clogged up that it would only run good at idle. Just driving it up a nearly flat driveway, you could see the fuel pressure drop below 10psi and the engine would die. The owner had replace the pump and filter and a shop was trying to tell him he needed a new FPR. We did some troubleshooting and found that the pickup/return at the tank were nearly packed solid with crap. Now the car runs good. This car would show good fuel pressure at idle, so it goes to show that you need to check pressure and volume. It failed the volume test badly as you can imagine.

If you can bring the car to the lakehouse meet, I'll bring some things to help troubleshoot it for you.

Crit

iTrader: (6)

Kent, one thing that might help would be checking the pressure under load. If we put my fuel gauge on the car and slap it under the wiper, we'll see if the pressure drops at high revs. That'll also tell you if there's a fuel flow rate problem (m-dot).

SirCygnus

iTrader: (1)

clamp the fuel return line with a vice grips.

cletus

Crit, I thought you still had my air/fuel gauge? If not, crap, need to find it. I know I didn't leave it in the FD.

gsl-se addict

iTrader: (3)

Crit: Sure. That is how he first found the problem with the other car I was working on. We tested in the driveway and left it connected when he tried to drive up the driveway. You could see the pressure drop to under 10psi and then the car would die. We then tested volume at the firewall and it was low. Retested before and after the filter (also low). That left the tank, so we dropped it and found the problem.

The jug test is simple and only takes a minute. Testing fuel pressure under load is also a good option and could help with an intermittant problem (like if the fuel pump was heating up and crapping out).

cletus

We do still need to drop his tank anyway to fix the pick up. So checking the screen wouldn't be a huge deal.

Crit

iTrader: (6)

Except that the screen is

BRAND


FREAKING


NEW


But yeah, wouldn't hurt to try.

Tim, I don't have your A/F gauge, but I've bought two since. The gauge in the dash of the SE has the same stereo plug as before, as does the REPU. If you can't find yours, either of mine would make an easy pull.

Acesanugal

iTrader: (5)

And end up gouging a hose that carries a volatile liquid? I think not. If you're going to make a suggestion like that, at least recommend using a towel or some small bits of smooth wood or metal to make it a clean seal and to prevent damage to the hose.

Crit

iTrader: (6)

Well, the FC guys are accustomed to engine fires.

Acesanugal

iTrader: (5)

LOL, well it was a stupid suggestion..

Greg Mix

I remember once we had a conversation about R-12 refrigerant for AC Systems. I believe someone siad it was still available. Does anyone know where I can find some R-12?

Or, how can I convert to the new R-134?

Acesanugal

iTrader: (5)

I've got two cans of R-12..

Greg Mix

Have old AC system what needs charging. How can I get them two cans?

2GSLSE

iTrader: (6)

On the fuel issue on a gslse there is a second fuel strainer at the fuel pump it is actually IN the barb on the pump and is cone shaped. I had one of my gslse's get clogged and starve for fuel on the high end it acted like a weak pump but after R&R the old pump was good as new. may want to check it out before dropping the tank.

RTRx7

iTrader: (2)

There is an r12 substitute available at some shops in my area.

Why not just do the conversion?

cletus

Found my gauge Crit. It was in Jeff's car.

He'll need to chime in, but basically it goes from rich to off the scale lean as soon as it warms up a bit. And stays there.

Crit

iTrader: (6)

Well now that's interesting. At idle, it goes from Rich to Lean as soon as it goes to closed-loop mode? Maybe adjust the trim pot on the passenger's side strut tower (R <--> L) and see how much it adjusts the mixture. If I read you right, and it really is all at idle, then it's something I've not run across. I'm thinking it's FB-section time. Kent also might have some ideas, but put a fuel pressure gauge on it ASAP.

glyphon

iTrader: (1)

i haven't really just let it sit there an idle, to see what the AFR gauge shows, but once you start driving, it drops off pretty quick...like it was almost completely lean by the time I reached the end of Tim's street, which isn't very far. and the entire drive home it was either like that, or no lights at all, save for the occasional blip when i would get back on the throttle after coasting.

i'll double check the the fuel trim, and try to get a fuel pressure gauge this weekend.

also, when i topped the tank off yesterday, to make sure it was a fuel pickup level issue, when i took off the gas cap, i got the hiss of pressure release that i was expecting, but what i also got that i wasn't expecting was fuel spraying out as well. Wasn't a lot, only a few oz, but never seen that before.

Greg Mix

As I understand it, the conversion, R-12 to R-134, would require flushing the system and /or replacing all of the seals because the old R-12 and its lubricant is not compatible with the new. I'm not sure. Can anyone who has done tell me what is involved in doing it yourself? I do not want to burn up my compressor.

Simply adding a can of R-12 or a suitable substitute would be far easier. Who might carry a substitute for R-12?

gsl-se addict

iTrader: (3)

Try your test with the gas cap off to eliminate the possibility of a bad vent causing vacuum in the tank. That could hurt fuel flow as well. If is rich at idle (should be) and then goes lean if you try to drive, it sounds like you have a clog somewhere or the pump is dying. I would start testing volume and pressure. I would start with volume as you don't have to buy or borrow anything for that test. Just need a gallon jug and a screwdriver/pliers to remove the hose clamp. The volume test will tell you a lot.

If you are going to Crit's lakehouse next weekend, I'll bring my fuel pressure tester and some tools and we can see what's going on.

glyphon

iTrader: (1)

Ok, I'll try and do the volume test during lunch. I think i've got a 1gal jug.

t_g_farrell

iTrader: (1)

Thats probably techinically correct but I've done 134A conversions by just flushing
the system to the air and recharging with 134A. Didn't replace the seals or dryer
or anything else. Been working for over 5 years on my old 93 Mazda Navajo. I
think AC shops feed you this line to get you to pay more and to intimidate folks
from doing it themselves.

What can happen is the 134A operates at a higher pressure so you want to
under fill it a bit. I think thats where all the seal nonsense started because
if you over fill with 134A it may blowby some sealswhen the system is under
a heavy load. I had this happen before when I overfilled. Makes a big cloud
of smoke and sounds scary but doesn't seem to hurt anything except you
have to refill it again with less.

I always just stick an instant read meat thermometer in the middle AC duct in
the dash and turn the AC up high with a high fan setting. Then I fill until the
temps come down below 50 F. This is how the AC guy I went to did when I
watched him fill it once with R12.

Crit

iTrader: (6)

Jeff, sounds like fuel starvation. I'm not sure if your fuel pump has the little screen on the inlet, as they're not available anywhere and I know I've seen a failed one (may have been for your car). You definitely do have a new screen on the hardline pickup in the tank, though. I don't recall the status of the fuel filter, though, either. In any event, I've got a spare fuel pump bracket with FPD that you could build up with a new pump to make the swap easier, if it comes to that.