Saw the other post on stalling but wasn't sure if teh crossfire would narrow down to it's own inherante problems. This is my friends car and I am helping him work on it.

Background - 1982 Crossfire - Car si stock and has had an loopy idle since it got it from his dad but always ran fine. He was stopped at a light and it just stalled out and didn't fire backup. I can start it and feather the gas whcih will get it to about 2000 rpm, when I let off of the gas itr will drop to 500 rpm and bounce back to 1500 rpm once or twice and then bog down and die.

The fuel pump was replaced previously with not much mileage on it. The coil, module, cap and rotor were replaced today. When you fire it up you can see it spray fuel into the intake. Removed the plugs from the distributor cap and I can see a small spark arching from wire to cap terminal.

I ran na constant hot wire from the battery to coil to get it fuel power and still did the same thing. Where do I go from here and yes it has gas in it.

 

Have you done a code reading yet?

If so what is it showing?

Top of my head I would say

It sounds like either the oxygen sensor or fuel pressure.

 

The engine light dosn't come on so I didn't check the codes. I take it I will have to go buy a reader. What kind should I get to read the codes?

 

A paper clip.
Mike

 

Get some carb cleaner-remove the air cleaner-start the engine-spray the carb cleaner back and forth between both injectors-if you can manage to keep the engine running then you are probably low on fuel pressure. Remove the fuel line from the drivers side injector body and put a pressure gauge or vacuum gauge(which usually has a pressure side)-if you only have 2-4 pounds the pump could be bad or when they replaced the pump they didnt get the clamps at the short hose at the pump tight or they didnt even install them.

 

Just got back from his house and I ran the jumper and it continued to pulse "12" for about 15 times before I pulled it out. I know thats a test code but I saw it also shows that this this indicatees the distributor spark tuning reference pulses generated by the pickup coil are not received by the ECM.

I ran it with the air filters off and it has a good solid stream of fuel on both sides.

With the computer constantly pulseing 12 does that mean the ECM could be bad?

 

I have run into this and if the fuel pressure is correct. You probably have major vacuum leaks. The throttle shafts can be worn out causing a vacuum leak there, check for excessive play in them.

Idle air control valves will give you a reading when the scanner is installed and it will tell you if they are closed and if they are... you definately have vacuum leaks AFTER the throttle bodies. These valves are used to maintain a proper idle, when the rpm's change quickly such as panic stops, or revving the engine and coming back to idle. I have removed them and often times found a hard deposit of carbon that prevents the valve from functioning properly and seating correctly.

Top intake gasket, main intake body gasket, vacuum hoses to brake booster and headlight system may be leaking vacuum.

CAREFULLY spray carb cleaner or brake clean at the base of the intake where it meets the cylinder heads. If it is not idling when doing this, it may be hard to detect a leak. 2000 rpm won't work, must be at idle so you can detect idle rpm change.
EGR valve stuck open will cause it to die or make it very hard to start if at all.

Oxygen sensor, like earlier mentioned can be the problem also but you can read its values on a scanner and that data can aid you in seeing if it is bad. Even if it works it may be contaminated and need replacing due to excessive running in a rich fuel condition.

Make sure that you have NO exhaust leaks at the cylinder heads or anywhere in the system BEFORE the oxygen sensor.

If your friends dad has had the car for a long time, and knows that he did nothing to the engine for along time, I would bet it is a dry, leaking gasket issue along with the possibility of bad throttle bodies.

Is the fuel QUALITY good. No crappy no-name mom and pap gas station gas, the good stuff. Premium is preferred. Was the car stored for along time? Outside in the rain? Maybe water in the gas? Poor fuel quality will cause many problems.

Hope to hear from you on any further information and results of your tests.
GMC
"DUB"

 

No, that means the computer is going into field service mode and there are no trouble codes.
Most common problem is the fuel pump. Almost new doesn't mean good. Unfortunaly there is not an easy way to check the pressure without the test equipment. If it runs better when spraying carb cleaner down the throttle bodies the fuel pump is most likely weak. Only the 82 and 84 vettes use the low pressure pump. If someome tells you to use the 85 pump you may blow the pressure regualtor in the throttle body.

As for the lopy idle. With the engine running spray some cleaner along the back edge of the intake. They have a bad habit of sucking in the gasket between the upper and lower plenum.
Mike

 

No code "12" is the entrance and exit codes that the computer uses. It lets you know when it is starting. It will display code "12" three times and then start displaying any trouble codes. When all of the trouble codes have been displayed, it will display code "12" again. So.... knowing that the computer displayes ALL trouble codes THREE times, including code "12". If your get code "12" four times, you have no trouble codes stored in the computer.

 

Car was garage kept. I will check for air leaks later on this week and for fuel pressure. What would the fuel pressure be for a low pressure 82' system?

 

CFI requires 9-13PSI. New 82 pumps provide this minimally when new. Once they age, they dont provide this level of pressure. Aftermarket pumps are also known to fail prematurely. Use AC Delco only is the word on the street for this item.

I do recommend going to an 85 pump (AC Delco EP241) for better fuel stability through the RPM range. Many CFI guys go with the 85 pump for stability and have ABSOLUTELY no problems with it.

The pump provides flow, the spring loaded regulator provides the back pressure orifice to keep your fuel in the feed line at the required pressure.

Go over to the CFI forum and ask more about this upgrade or go to the C4 tech forum and check it further if you feel insecure about it.

I've been running this set-up with no issues, other than greatly improved throttle response.

 

I'm curious as to how many known incidents of "blown pressure regulators" you know of? I know of at least 6 82's that have upgraded to the 85 fuel pump without any problems.

 

More than I can remember. I was working on crossfires when they first came out in 82. Back then we called them misfires. The last one I worked on was over a year ago for a blown regulator. You''ve seen six, I would see six a month during the eighties. Vette, camaro, firebird, and cavalier. The low pressure pumps weren't very good back then and upgrading to the hi pressure pump appeared to be the cure. Some held, many didn't.
It's not the pressure causing the problem, it's the reserve pressure. You've got a regulator designed to handle 20 psi reserve pressure and you're pumping 60 psi into it. Why do yoiu think the throttle response is so much better?
If it works for you then go with it. I won't recommend it or install one if asked or paid.
Mike

 

I myself would install an inline adjustable pressure regulator to adjust the pressure to more "comfortable" pressure than that of the higher pressure in 1985 and on models. BUT...tracdogg2 seems to much more experience in it than I have. I have only worked on about a dozen or so over the years. And they all were in Corvettes only. My concern is that I know that the fuel lines in 1985 and on have the rubber hose crimped onto it because of the pressure and their design. And on the 1985 and on models the pressure line coming out of the sending unit, where the rubber hose attaches, has two clamps on it instead of one. Dealing with the fuel system I get very concerned because I always do not want to hear that the car turned into a "roman candle". Fuel under pressure is just that, under pressure. But increasing it from factory design makes me over think things at times and I am always cautious when changing fuel system parts. Remember ladies and gents, I do this for a living and have to watch out for the legal "sharks" who would just love to sink their teeth into me and make a buck for themselves and their clients. I still honestly feel that you have vacuum leaks of the throttle shafts are worn and have excessive free-play. tracdogg2 do you agree/disagree? GMC "DUB"

 

Me for one.

 

I've installed this pump and have no problems. Why would you push the pressure up over 20. They run fine at 15 -20 lb. Up to or over 60 lb. That's some "Hot Rod"!

Just my thoughts...

Dave

 

I have an 85 pump too. No problems. I don't think its PSI from the pump its volume.I think the number is around 40.


As for this persons problem. It sounds fuel related. Check fuel pressure or I would pull the pump and check it. I have seen a few here where the rubber hose on the pump in the tank has deteriorated and cause this problem.

It could be a vaccum leak but this usually results in surging or high idle not low idle and stalling. The only think I can think of that would cause low idle and stalling is the EGR Valve.

Off chance its the TPS.

If you want to check the ECM start the car and disconnect the the MAP sensor wire or another sensor. It should set the light off. To clear the light pull the fuse beside the battery for 30 seconds.

Don't mess around with the throttle bodies at this time. They are factory set. You will throw things out so far you will never figure out the problem. Unless a previous owner already got to them.

Jim

 

I just finished one that had fuel spraying from the injectors but would stall. I could keep it running by spraying carb cleaner into the throttle bodys. Checked the fuel pressure and it was 2 lbs. Pulled the pump out and the 2 clamps on the rubber hose just above the pump were gone and the rubber was really soft. The pump was OK but the fuel was just spraying back into the tank and was not being forced to go to the engine. I put 2 clamps on and the car ran fine. I then replaced the pump strainer and fuel filter.

 

Checked the fuel pressure this morning and it was at 2 psi. Changed the fuel filter and regrounded the fuel pump and it came up to 2.5 psi. Dropped the tank and pulled out the unit and the line was split down the middle. Had to replace it with a standard fuel injector hose but the pressure is now at 11 psi and running real smooth. The loopy idle is gone now so i'm guessing that it had a small tear to begin with when he got it 2 months ago.

 

Oh yeah. Thanks for all the help guys.