poor running 84

[Buccaneer]

Nice to hear that you're finding what appears to be the root cause of your problems. A bad or interemittant coil can be a PITA sometimes. This may have been your backfire issue like I mentioned earlier.

Keep on probing until she's good to go. Once you get it setup and running right, they tend to run like a top.

How many miles does the car have?

 

[chevyagain]

car has 86k this is proven by carfax, loved danny and the juniors

guess what guys, this is christines clone, just went to start it fully charged battery
no nothing, no starter clicking, no buzzing, nada
ground to engine???? ignition switch????? isnt this fun
the return of christine due to come at a theatre near you

 

[Florida Guy]

I'm not all that familiar with your 84 but a few things to check that are common to all vehicles - battery cable connections at the battery and at the starter solenoid. Just for the hell of it, verify that no one has added an inline starter relay some where between the battery and the starter. Check for voltage at the solenoid from the switch while trying to start. (Be careful, it may start.) If 0 volts, could be ignition switch or safety switch (Park or clutch engaged switch). If 12 volts to solenoid problem could be solenoid. That should help isolate the starting problem.
Good luck.

 

[John Robinson]

Check the battery terminals to be sure they are not loose in the battery. Delco not so long ago had a problem with the terminals pulling out of the battery if they were overtightened. Make sure the terminals are clean. Also you might check the positive and ground wires for the battery for continuity. You may be moving things around and occasionally getting a bad wire to connect. The other thing that can happen is the ignition safety system has a bad switch. For instance if you have an automatic and are trying to start it in P you might try to start it in N if it starts you may have a bad contact on the shift position linkage. If you have a standard shift you may have a bad switch on the clutch. It is easy to check these by pulling the wire connector and using a piece of wire jump the wire connector not the switch and see if the car starts. If so you have found a bad switch. Good Luck I make these suggestions because it sounds like the previous owner was a sledge hammer mechanic and had given up on the car because he did not have the skills or patience to make things work so he sold the car.

Ok when you say nothing happens do you mean that you do not have anything like lights or radio?
If that is the case everything starts from the battery. Remember the battery has to send power to all these things for them to work if they don't work then your problem with the starting is tied to the battery or it's connections. I would suggest you have the battery charged and then take it out to a parts store for them to load test it.

 

[chevyagain]

thanks john battery terminals cleaned and tightened, have lights, radio
just wondering why the engine started immediately when i switched
modules thaen let it sit for awhile and nothing. some say cioil has nothing to do with module i say module may or may not handle a hotter
coil, i really dont know, maybe i get a few starts then they fry
its a MSD your going from20k volts to maybe 50k this doesnt affect module

 

[John Robinson]

You might try this. If you have a volt meter check the voltage in the battery. You should have 12.5 to a little over 13 volts in the battery. While holding the probes on the battery have someone try to start the car. The voltage should not drop below about 10 volts when the starter engages. If the voltage drops way below that then the battery is probably the culprit. Before you try this disconnect the cables and charge the battery for a few hours.

 

[chevyagain]

trouble is i have nothing, starter wont engage, turning key is like having no battery at all


put meter on battery 12.10 volts, turned key dropped to11.65

 

[Florida Guy]

What was the voltage at the key switch input to the starter solenoid? And are you sure it is in PARK?

 

[chevyagain]

yes it was in park, will be checking voltage tp solenoid later this afternoon
will keep you posted


have 10.65 volts going to solenoid, still no start, hit solenoid lightly started right up
ok, got ot siticky solenoid. still looking for plug with pigtails for fuel pump relay any help???

 

[Florida Guy]

No guarantee but try this one. They have pigtails for several parts. They also give a toll free number for assistance.

http://catalog.autopartsgiant.com/

 

[Florida Guy]

http://www.rockauto.com has a 1984 fuel pump relay connector and pigtail for $31. This may be what you are looking for.

 

[chevyagain]

thanks, i get closer everyday to get this running right

ok guys heres where im at, starts fine, being that it was a sluggish solenoid
idle seems to pick up slowly, but two high. running very rich, you can smell it
as soon as you step on the pedal to goose it, fireball at rear throttle body
big pop. had someone here, mechanic, not a crossfire expert, thinks possible
fuel pressure regulator on that TB. ONLY AN OPINION. pop is due to a lean
condition, but then why running rich at idle????
thanks again--------christine

 

[wishuwerehere82]

thanks, i get closer everyday to get this running right

ok guys heres where im at, starts fine, being that it was a sluggish solenoid
idle seems to pick up slowly, but two high. running very rich, you can smell it
as soon as you step on the pedal to goose it, fireball at rear throttle body
big pop. had someone here, mechanic, not a crossfire expert, thinks possible
fuel pressure regulator on that TB. ONLY AN OPINION. pop is due to a lean
condition, but then why running rich at idle????
thanks again--------christine

The fuel pressure regulator is in the rear TB. The fuel runs from the fuel pump, through the front TB, through the fuel line between the two TB's, into the rear TB to the pressure regulator. The pressure is adjusted from under the rear TB by a screw-type spring loaded diaphragm. After the regulator, the fuel goes back to the tank. So, it's a continuous loop from the pump back to the tank.

Now, if you want to see what the pressure is, you need to remove the S-shaped line between the two TB's and make some short lines in order to put a pressure gauge in line between the TB's. That's the only way to do it. You can screw up the fittings and twist the tubing real easy trying to remove them, just to check to fuel pressure. But if you do, there are gauge kits you can put in permanently.
http://crossfireinjection.net/DCS Read more 3.html
They also have regulator adjustment tools there.

It's possible that the regulator is set too low, or more likely the pump can't provide enough flow to keep the pressure up at 12 PSI. Fuel pressure is critical for the system to run right.
So it may run a idle, because you aren't using that much fuel, but as soon as you need more, the pressure drops like a rock.
Or there might be a restriction at the fuel filter that is causing a pressure drop.
You might want to change the fuel filter before you go to the trouble of measuring the fuel pressure. That's what I would do first.

But before you can balance the TB's, you need to verify the fuel pressure is correct and constant at all RPM's. That's the first step in balancing the injectors.

The other thing that is causing it to lean out, is that The TPS voltage is set for 525mv at the speed it is running, which is idling too high.
The TPS needs to be at 525mv at 500 RPM with the IAC passages blocked. So until you get the RPM down, the TPS will be set too lean.( I know, it's a lot of back and forthing to get it set up right, but once you get it...It's Set!)

So go back to the Corvette Fever article and get a feel of the steps necessary to get it adjusted, then do it.
http://www.corvettefever.com/techarticles/4688_chevrolet_corvette_efi_system_tuning/

 

[geekinavette]

Most excellent description Pete!

Only "popping" out of the rear TB is a bit odd tho...unless there's a restriction between the two, pressure would be identical at each injector. Rear IAC sticking open? I might try blocking off the IAC ports all together and see if that makes any difference, as a stuck open IAC would for sure cause a high idle (and maybe a lean backfire?).

What temperature are you letting the engine get up to? These things run VERY rich until they warm up to operating temp.

Bill

 

[chevyagain]

thanks pete for all your time and effort, it is greatly appreciated
i do have a new fuel filter and my tps is set right, however
i dont recall at what RPM will double check, maybe im really homing in on christine. like that fuel pressure gauge setup
will get back soon--------------john

 

[chevyagain]

bill
i was up at around 210-220 temp wise
both IAC'S ARE BRAND NEW

 

[wishuwerehere82]

Now keep in mind, you set the TPS just to get it in the general operating range to get it running, and keep it running.

The final TPS setting will be done only AFTER balancing the flow on the TB's.
So I can guarantee that the TPS, balance screw and the idle screws are NOT set properly now. You HAVE to do the entire sequence of steps in order to get it set up properly, without any shortcuts or assumptions.
Once that is done, if it still backfires, it must be:
A)A still existing vaccuum leak, or
B) Valve problems.

 

[geekinavette]

bill
i was up at around 210-220 temp wise
both IAC'S ARE BRAND NEW

New does NOT always mean good! Don't assume it's good just because it's new...

Bill

 

[chevyagain]

ok with new plenum gasket, and all the parts i replaced, double and
triple checked all; vaccum lines, where didnt i look for a vaccum leak

 

[geekinavette]

EGR valve?

Did you try blocking off the IAC ports?

Bill