Redwing's Car - An Update

[siteunseen]

Zed Head that makes sense for my car's need to add more fuel, it had a huge vacuum leak. But after fixing all that it still needed the potinometer to fine tune the stumble at 2000 to 2500 RPMS.

[SteveJ]

I ordered a 5K pot earlier today based on other threads. I'll bring a vacuum gauge, too. I'm hoping the remaining problems are electrical in nature and not clogged injectors. Of course, I didn't see much in the way of vacuum lines on the intake. I'll have to do some studying in the FSM.

[gwri8]

Any chance Jai could run a bottle of FI cleaner in the meantime?  Something like a bottle of Lucas or similar product even at idle couldn't hurt until the 29th.

[EuroDat]

Hi Steve,

Welcome to the frustrations of problem solving an old j-jetronic type efi system. I have explained my pressure test method a couple of times in other threads. Jai's system is loosing prssure quickly so it should be easy to find. Its not causing her problems though fixing the pressure loss will help starting.

Interesting point when it was warmed up and the pressure increased to 34-36psi. Thats approaching max for a good functioning fpr. Sounds like the vacuum dropped off completly to get this pressure. Normal idle pressure should be around 28psi, 30 seems to be a bit high, but could just be calibration issues.

The potinometer would help, but I don't think it will solve the problem. When Jai got the car it was running fine and this started suddenly. The temperature tweak solves problems that take a long time to evolve.

The AFM cops a lot of blame and its often adjusted with no real results. Mine was way off until I adjusted it by the method on AtlanticZ and added the temperature tweak.

Test method once you have fitted a pressure gauge.

1- Build up system pressure (remove solenoid conector on starter and turn ignition key to start to run fuel pump). You may need to do this a couple of times to buid up pressure while going through tests.

2- Stop pump and clamp hose after gauge. If pressure drops its the check valve in the fuel pump leaking back to the tank. If not

3- Build up pressure again and this time clamp the return line from the fpr. It wil be next to the fuel gauge. If it now holds pressure the fpr is leaking back to tank. If not

4- Cold start valve. The hoses going to the csv are too short to clamp so I remove the two screws and gently pri it loose from the manifold. Remove the EV1 connector and build up pressure again and check if it drips. If not, the only source of leakage after this is the fuel injectors.

When you pressure build up for the testing, you should be getting 36-38 psi. That the max for the fpr, like removing the vacuum hose while running or WOT no vacuum conditions.

Goodluck solving it.

[SteveJ]

Any chance Jai could run a bottle of FI cleaner in the meantime?  Something like a bottle of Lucas or similar product even at idle couldn't hurt until the 29th.

I have some in my garage. I can add that to the list for the next trip.

[240260280z]

I'll guess at fuel pick-up issue/clogging in tank.... from experience.

[Redwing]

Supposedly the injectors were cleaned and checked in Jacksonville, where she was from Dec.1 to Mar.1. But he said he changed the oil too, tho when she got here it was Black. So who knows.

I don't know actually what was done except the 2 small surface rust spots. I know that was done, because there is red paint now.

Greg, we're you asking if the FI cleaner could be used before the 28th? Does that need to be done before y'alls visit? If so I will get some to do it, but RedBird will only idle in the carport. She is not going anywhere.

Thanks everyone for your help, in whatever way you share.

Jai

[SteveJ]

Philip, I guess I can't rule that out, either. That would explain the rapid loss in pressure the first time the car died in my testing. That could also explain the problems Jai had today. I could drain the tank again. I also did put a small fuel filter in before the fuel pump. I didn't put the car up on ramps, so I didn't inspect the fuel filter yesterday.

 

I'm trying to be methodical and focus on addressing and eliminating each issue I find. I am beginning to think some of the issues confound one another. It's also a challenge to make sure I have everything to test loaded up in the car to take over to Jai's place.

 

I also have to admit that I'm hoping the problems found have easy solutions since Jai does not have the funds to purchase a lot of parts.

[240260280z]

Buy some low pressure hose and fill a gerry can with gas. Run to the fuel pump in and return line. You can pick these off at the tank in/out.

 

You'll have to do a short run with the can strapped in the back deck but it will be a quick test to save a lot of headache. 

[Redwing]

Hi,

Feeling I need to do something to pass the time until Steve comes again. Decided I would check the fuel pressure gauge, and start her again just to see what happens since she has been resting for 3 days.

The gauge was on zero when checked before starting. No surprise.

Starting her, she said OK, and immediately jumped to life. No hesitation.

On checking the gauge while running, it appeared to be on 32. Let her run for a short time, and cut her off.

Rechecking the gauge and it showed 28. I will do a recheck in a bit to see how quickly it drops.

So good to hear her "sing" to me! Hhmmmmmmm.....

Jai

[SteveJ]

WIth the way it was running most of the time, I'm suspecting that it's picking up debris from the tank when it's crapping out. The next planned visit is the 29th. I guess we'll be focusing on the tank again.

[Redwing]

Rechecked the gauge, it has been a little over an hour, it is showing 26 now.

When she was running earlier, it was smooth as silk. No roughness.