garretthes

While driving the 79 I notice a fairly loud whine coming from the rear. I'm assuming it's the diff. I have an 83 Turbo parts car. Will the diff fit? Should I change the shafts as well?

Maybe I was hitting the ECU a little harder than it needed The new harness for the coolant temp sensor and thermo-time definitely helped. It runs much smoother and stable with no smoking. The exhaust smells right. It still has a miss though. I'm leaning towards a bad injector. I wish they weren't so expensive I would just replace them all and be done with it.

Fixed the short in the ECU but still not quite right. Much better though. Just ordered a new harness for the coolant temp sensor and thermo-time. I think the wire is corroded.

Actually the short appears to be in the connector at the ECU.

Seems I have a short in the ECU

That's what I want to here, the uncommon answers. Sometimes it helps

Also, watched the fuel pressure gauge. Runs at exactly 30 then as soon as you shut it off it pops to 25 but doesn't move, even after a few minutes. I'm thinking there are no leaky injectors.

Sorry guys. I must have forgot to post the fuel pressure. It's running at 30-32 depending on engine speed. When I disconnect the regulator vacuum line it pops up to 34 so it appears the regulator is working properly. There is no gas in the vacuum line. Also the vacuum is running low. It's between 5 at rough idle and 13 at higher rpm. I'm wondering if the injectors are dirty and staying open too long. We had the car running well BEFORE I drove it the first time. I'm guessing the drive shook up some of the crud in the tank (there was a LOT!) and caused the filter to clog. I'm also guessing some of the finer crud got through and has clogged the injectors. So today I'm getting another bottle of seafoam to add to the 4 gallons of fresh fuel in the tank. I will run the car again for 15 minutes or so and see if it doesn't improve. If not, I guess I should get new injectors.

So here is what it's doing now: Cranks OK but idles VERY low. It basically lopes along at 500rpm. The exhaust smells like gas. It runs rough at idle and higher rpm. I have ruled out the AFM, cold start injector and all the electrical connectors have been cleaned. After replacing the plugs then running it a few minutes I pulled one of the plugs and it was black and damp. What to check next?

OK, false alarm, the injector is now working. But it is still running very rich. I took it for a drive around the street and it runs strong, just rough. That's promising.

Installed NGK plugs and it still runs like crap! Running rich, blowing black smoke. And what's VERY frustrating is injector #4 is not working! I just pulled the fuel rail and replaced #1. This is insane

Well I solved the low fuel pressure problem (gas tank sludge) and replaced the bad injector. It still runs rough though. I'm hoping it's the plugs. I'm picking up a set of NGK plugs tomorrow. I'm praying this fixes it because I'm out of ideas. As of Tuesday I will have been working on this car 1 year. I REALLY want to let my daughter take it for a spin.

Finally got my fuel gauge hooked up today after a trip to Ace. I had 3 pounds of pressure in the rail. No wonder it wouldn't run. Pulled the fuel filter off (again) and poured the contents into a bowl. You can see what it looked like. I decided to drop the tank. After I got it out I pulled the sending unit out. OMG It was totally corroded. The tank is full of sludge. It never had a chance. So I pulled the sending unit from the parts car. It looked great! The tank looked great! Pulled the tank off the parts car and was cleaning it up when my wife noticed a small hole. Great. So now I'm patching the hole. Hopefully I will get it all back together tonight.

I don't think I have a vacuum leak. Isn't there something else that could cause low vacuum?

CRAP! The Summit Fuel Gauge doesn't have ANY connectors. Have to go shopping tomorow

That is bizzare!

I sealed the system last night and it is holding pressure and not leaking so I'm pretty confident that's not my problem. My problem is CAUSING the low vacuum

Removed the CAT only to find it has been gutted. Ordered a fuel pressure gauge. I guess I have to wait a few days to check the pressure

Did the yogurt leak test (except I used duct tape) and discovered that air is flowing freely into the throttle chamber through a tube. After blocking this off I found a pretty bad leak in the tube that runs to the valve cover. The manual calls this a 3 way but it only runs from the rocker cover to the throttle body on my 79. I'm guessing this is s special order vacuum hose since it has a 45 degree angle?

Would a lot of back pressure cause the vacuum to suffer? Would this in turn cause the fuel pressure regulator to fail which would increase fuel pressure on the rail and then cause a rich mixture? I have learned so much about this car but I still feel like I'm swinging in the dark sometimes. Before I tried to drive this car we had it running pretty good. At one point it sat for at least 30 minutes idling with no smoke and behaving normal. One of the short trips I made around the neighborhood it backfired pretty bad and sparks blew out of the exhaust. I'm thinking this was NOT good for the cat.

Guys I just keep wondering if the CAT is clogged. This is what it feels like. It will run for a about a minute then slowly die then I have to wait 10 minutes or so before it will start again. Does this ever happen to Zs? Also the previous problem I had was an immense amount of white smoke from running too rich. Could the extra gas have screwed up the cat?

Did you ever get this fixed? I would love to know what happened

No change. No leak. I tried moving the AFM door in and out and there was no perceptible change in rpm. Is that right?

Well I have to wait a while to test again. It won't run

Also I found a ground wire that screws to a bolt on the distributor under the cap. It has a bullet connector on it and is black. Where does it attach?