Demonic85

Well this sucker starts up and dies, wont stay running at all. It did the exact same thing when the original MAF died earlier this year. I'd just replace it but i'm worried there might be more to it like the burnoff module that could be causing it to go bad. The replacement that I got before wasnt new so it could have been bad luck too. I've been thinking about buying the Cardone w/1 yr warranty and if it goes bad too, then it would most certainly be a bad module... at least I think so. I'll keep rooting around in the FSM a bit more first.

CFI-EFI

Based on your previous post #5: "With the MAF plugged in, the car will start and stall after 1 second regardless if I try to give it gas. After unplugging the MAF the car still start up and idle until I hit the gas, in which case it stalls. ", unplugging the MAF DOESN'T solve the problems. I'm not sure what it is, but I think there is another problem even if the MAF is bad. I think you should find and fix that (those?) before you spend the big bucks. Remember, the used MAF previously installed only lasted a couple of months. Have you checked fuel pressure?

RACE ON!!!

Demonic85

Yeah thats what I was thinking too, but the only thing I can think of is the MAF burnoff module but I dont see a definitive way of testing it, only the circuits. Fuel pressure is set at 32-35psi which as I understand it is about where an '85 is supposed to be. I toyed around with that before thinking it was the problem, but only made it flood.

j3studio

evmlarry

I followed along in my FSM with what you're finding and saying... and based on the testing of the burnoff circuit, I'd say it's dead too. You should be supply 12 volts through it. Sorry bout your troubles, but you are giving me a chance to learn and follow along, so I thank you for that.

I agree also that this might be just one issue considering how it ran with it plugged in and not plugged in. I'll read through my FSM some more and see if I can help you along the way. Good luck with this!

evmlarry

FWIW, have you ran through all the "Hard Starts" checks in the Symptoms section?

Demonic85

Yes I have and it also ends with the MAF on that list as well. I found a way to test the burnoff module from the electrics section of the FSM. You jumper the A and E terminals of ALDL connector and turn the ignition on. This is supposed to make the module run and when turn the ignition off it runs the burnoff. I noticed that when I turned it off, I could hear a distinct click like a relay coming from the module. However the wires in the MAF did not glow at all.

This leads me to believe that power is going to the module but not going out to the MAF, or the MAF is just dead. I find a thread where a forum member had rerouted the wiring and ran it through a seperate relay to in effect bypass the module. I'm curious as to how he did it and I sent him an email. I'd replace the module but I cant afford to do so at this time of year and it would have to sit until January until I could afford to fix it. So i'm still waiting on him to reply back.

CFI-EFI

You could ohm check the wires from the module to the MAF, to be sure there is continuity. Then volt check the module output when doing the A/E ALDL test to see if there is any module output. There is no reason to spend time and effort bypassing the module with a relay, if there is just a broken wire between the module and the MAF. You seem to have a good start in your trouble shooting, don't stop half way through.

RACE ON!!!

Demonic85

Oh i'm not giving up. I tried to do the ohm check but it requires fabbing up a connector of some sort or piercing the insulation on the wires to do it. What I did was use a voltage meter on the plug and there wasnt any voltage at the connector. I didnt see any broken wires in the circuit but neither did I check the voltage AT the module itself. Would that really make a difference?

I wanted to bypass it so I wouldnt have to worry about replacing the expensive module and it would still work the same. I just drive my car, not worried about it being original. I'm going to check for voltage at the module itself, see what comes up...

Demonic85

I rechecked the fuel pressure (the first time I tested was before replacing injectors). Fuel pressure will not rise higher than 25 psi and then immediately drops about 4 psi after the pump stops running. The pressure steadily drops and I would say takes about 10 minutes before there is no more pressure. I checked all the fuel lines, checked for leaks, nothing wrong there. I followed the FSM and it says that I have a leaking injector. I just replaced these! Is there anything else I should look at before tearing down the plenum again?

bigbob1

I am curious to see what you find out. I have an 85 with the exact same problem right now. I can unplug the maf and get it to run but it runs horrible of course. I live close to you let me know if you need to swap some parts to try and solve your problem.

Demonic85

Have you tried jumping the A to E terminals like I mentioned before? I would also recommend testing fuel pressure as well. It sounds like I may have multiple problems with mine, lousy fuel injection

evmlarry

If I remember correctly, a bad seal on the o-ring for the injectors can also cause this issue.

I had a very similar issue as you when my fuel pressure regulator diaphragm took a dump. Pull the vacuum line off and jumper the pump to run. See if fuel comes out your vacuum port. I believe you can jumper the pump at the ALDL if you want it to continuously run while you test. I read that on here some where before. But you can also, probably, tell pretty quick by just doing the ole turn the key to ON test.

Demonic85

Right now I dont have a vacuum line hooked up to the regulator and there is no fuel coming out it whatsoever. Its an adjustable Holley unit. It has correct pressure at first and while running so long as I keep giving it gas. The fuel pump was replaced earlier this year and is in good working condition. How can an O-ring cause the the injectors to dump fuel in the engine??? Yes I pulled the plugs and they're wet. I followed the instructions while putting the new injectors in, oiled up the rings like i'm supposed to.

CFI-EFI

If there is a break in the wiring between the module and the MAF, it sure would. That is why I suggested checking it for continuity. Checking for voltage at both ends accomplishes the same thing.

Fine but don't spin your wheels bypassing it, if the only problem is a broken wire. Diagnose and fix the actual problem. Don't "shot gun it".

The fuel pressure bleed off could be injectors. regulator or the pressure bleeding back into the tank via the check valve in the fuel pump, the pulsator, or a leaky pressure hose. That isn't affecting this problem. Fix this before you worry about the pressure bleed off.

RACE ON!!!

evmlarry

I have the same Holley... first diaphragm crapped out on my right out of the box. Fortunately this second one has been ok so far.

I actually read many times on here where people have recommended to check for a faulty o-ring on either the rail or the manifold with fuel pressure issues. You can do a search and find it a few times... I honestly don't know personally how it could affect it other than it'll have a loose seal cause it to bleed by.

Demonic85

Well I'm not 100% sure on the MAF situation, but there is definitely something wrong with the injectors. The fuel pressure drops and theres fuel coming out of the spark plug holes. I mean how do I know thats the entire problem right there. If getting another set of injectors (since they are new and defective) wont fix it, then its the MAF. Unless you think the MAF cause cause a loss in fuel pressure.

evmlarry

You know, reading that makes me think you might want to actually lift the injectors and energize the fuel pump... see if any injectors are leaking.

I know, it sucks... pulling the plenum. These cars sure do get frustrating, but if it's not your daily driver and it's your hobby hang in there. Maybe walk away for a few from it and come back. They can be real PITA.

And I think they never appreciate the work you do on them cause they always find somewhere else to break.

Good thing is they're only mechanical... you'll be able to figure out the issue. There's only so many ways they can function and break.

CFI-EFI

Absolutely not! But the loss in fuel pressure doesn't make it do one thing with the MAF connected and another with it disconnected. Focus on one problem at a time. The MAF could be responsible for the wet plugs, by making it run rich, but not the drop in pressure. Do you KNOW the injectors are leaking? Usually you can assume new injectors aren't leaking. Maybe the injectors you replaced weren't bad.

RACE ON!!!

Demonic85

The old ones ohmed good but I replaced them cause they were 22 yrs old, probably going bad anyway. The new ones I know are leaking cause I dont even have to start the car for fuel to leak down in the cylinders, just turn on the fuel pump.