10K on re-build, top off, and then *&#*&@(*&@#$#

[Groesbeck Hurricane]

I've been having a decent week. We're getting ready to break ground on a new house. Might have the old house sold. Looking at same payment on new home and just enjoying life on the drive home. About to make a left from a stop light, go to first, give a little gas, light is turning green, and I feel a slight shudder (I think, I might be imagining this), look at the RPM's as they drop out and note that the druck press is reading zero. Nothing. Oil pressure is out also. Big backfire like a .38 and I'm cutting the ignition off. I turn the ignition to on to see what is reading and the temperature is normal, I hear the fuel pump, and the druck press is jumping up and down.

I did have three small backfires when I pulled out from the bank, but thought it might just be the gas I just put in, just trying to comfort myself I guess.

Any thoughts on what I might be facing? I'm thinking that the motor has to come out this weekend. Opinions are appreciated. I'm just really bummed right now. Now I have to start driving the pick-up again and I hate trucks!

[HarryD]

David,

Did the car run after the incident.

My car, seems to crave attention every once and while. She does so by sometimes being hard to start and then surges at idle. If I drive her hard, more often than not, the symptons go away. Sometimes, she needs a visit to the CO anaylzer to get the mixture adjusted. I chalk it up to "the joys of an older car" ownership experience and do not obsess about it oo much.

That siad, do you have any more symptoms?

[Groesbeck Hurricane]

Harry,

I was a bit scared of trying to start her again. I know the mixture was a bit rich, but...

Hey, I forgot, there was about three ounces or less of oil under the rear (under the fan) end of the car. It was dark. Maybe I should check the oil level?

The only other issue is that she is difficult to start after she has sat for from one to two hours after being driven. She starts up just fine if allowed to sit for three hours or more.

Thanks,

[ischmitz]

I can only imagine how you must feel right now. I tend to hear flys coughing these days on my rebuild every time I fire it up.

Back on topic.

I would first check the really simple things such as a bad electrical connection from your pressure sender to the instrument. If not both the pressure read zero and the oil light came on at the same time Iwouldn't be too concerned that the engine went south.

When you talk about a shudder could this point to a poor ground connection in general cutting out the ignition or was it something mechanical?

Did I read correctly that you fired the car up again and had a couple of more shudders then?

A jumping needle means a poor connection (corrosion) right at the pressure sender. Ask me how I know. I had the same thing on my 2.7. That needle was all over the place.

In case you have not fired her uo try to disconnect the ignition and start cranking it. Oil pressure should build up within about 5 to 10 seconds. First the light goes off and then the needle should move (given the engine is cold). If that works I would go further and fire her up to see if she runs.

Ingo

[HarryD]

Originally posted by Groesbeck Hurricane
Harry,

I was a bit scared of trying to start her again. I know the mixture was a bit rich, but...

Hey, I forgot, there was about three ounces or less of oil under the rear (under the fan) end of the car. It was dark. Maybe I should check the oil level?

The only other issue is that she is difficult to start after she has sat for from one to two hours after being driven. She starts up just fine if allowed to sit for three hours or more.

Thanks,

I assume you looked at the CIS Troubleshooting Chart .

After eliminating some of the home things you can check per the chart, I would get the mixture adjusted. For me anyway, it makes a world of difference.

[konish]

David,
First, your warm start problem sounds like a bad accumulator. When the car cools for longer periods, the vapor lock condition goes away. Shorter durations...like a few minutes, can actually make the problem seem worse as the gas does not get reciculated back into the tank.
As for your lean popping and shut down. An this may be obvious, but I have to ask. On your rebuild did you change the fuel filter? Is your tank rusty inside? Seems like a problem like this that happens all of the sudden sounds like fuel starvation caused by a fuel filter that finally stopped flowing due to crud...a large particle of crap in the control piston of the fuel distributor or clogged fuel line. You may have also developed a vacum leak that finally manifested itself in a violent manner. Not sure how to explain the oil at the rear of the car though...

R/
Dustin

[Groesbeck Hurricane]

Harry,

I did not think of troubleshooting the CIS. I'm doing that tomorrow. Thank you for the direction!

Ingo,

I will check the connections in the morning before the CIS. Not a bad idea. I am not sure the shudder was the car or me when I saw bad things. Just not sure which...

The small backfires were when I left the bank and headed home. She died on the way home.

Unless there is a contraindication, I like the idea of undoing the ignition and turning the car over to check oil pressure. Thanks!

Dustin,

I changed the fuel filter, but do not think I changed the accumulator. That is a good thought. The tank was clean but I did let it get rather low this time (light coming on) before filling her up at Shell. When she gets started again, I'll do a check of vacuum hoses. I replaced most of them on the re-build but one never knows.

[Groesbeck Hurricane]

Connections to the sender unit were clean, no corrosion. I disconnected the ignition wire and turned her over. Pressure built up within 10 seconds and was normal. I reconnected the wires and she fired up. Ran smoothly. I have the factory manuals out, THE re-build book, 101, Bentley, and Haynes (yuck). I'll be reading about CIS and the joys of ownership! Looks like I will be getting a new accumulator. I'll be looking for a way to set fuel mixture right without instruments...I know this doesn't exist, but I need something. Maybe not working on her in the last several months has her feeling lonely and mistreated. But she was running fairly well.

[1980SC]

I had some very loud backfires, like a gun going off right behind me, when a hose came off my deceleration valve. A big vacuum leak can cause them. It's probably just a CIS or vacuum problem.

-Rob
1980sc

[Doug Zielke]

David,
When you did the motor work, did you replace the intake boots?
And.... inspect the other CIS rubber hoses?

When I had my motor out, a lot of that rubber was deteriorated=vacuum leaks.

[Wayne 962]

This does sound like typical fuel injection troubleshooting problems - not a major engine mechanical problem.

-Wayne

[Pettybird]

The only other issue is that she is difficult to start after she has sat for from one to two hours after being driven. She starts up just fine if allowed to sit for three hours or more.

Thanks,__________________
David



I've got this, too--

Start the car in the snow, fine. Start the car on the face of the sun, fine. Run it for an hour, shut it off for 15 minutes, fune. Run it for an hour, leave it sit for an hour, backfires, has a low idle, and runs like it's got a carb with no choke at low rpm's.

How long does it take a fuel accumulator to empty? What if I try to 'prime' the motor a couple times by turning the key on and off (as if i'm trying to refill an EFI car after running it completely out of gas).

It runs poorly for about 5 minutes, then perks back up as if nothing's wrong. It's the ONLY drivability problem I've got...

The car is dead stock.

Thanks,
Doug

[Wayne 962]

Originally posted by Pettybird
The only other issue is that she is difficult to start after she has sat for from one to two hours after being driven. She starts up just fine if allowed to sit for three hours or more.

There are two components that can fail that lead to this problem. The first is the accumulator. The second is the check valve in the fuel pump (yes, there is one in there on CIS pumps). 99% of the time, it's either one of these...

-Wayne

[Pettybird]

Originally posted by Wayne at Pelican Parts
There are two components that can fail that lead to this problem. The first is the accumulator. The second is the check valve in the fuel pump (yes, there is one in there on CIS pumps). 99% of the time, it's either one of these...

-Wayne

Thanks for the quick reply, Wayne.

Is there a way to test which is foul, or should I do the check valve first since it's a quarter of the cost of the accumulator, and then the accumulator if that wasn't it? I see a part number for the check valve- this is separately replaceable, correct?

I'm unsure as to why this would cause a warm start problem and not a cold start problem. I'm not doubting you--I just can't work out the problem in my head. Does the cold start valve compensate that much? I can understand if the pressure goes away slowly enough to allow good hot starts, but it's the cold start that bothers me. It's not perfect cold, and it sometimes backfires at first, but I chalked that up to this being a 25 year old car with 30 year old technology and 110,000 miles on the clock. Is the 7th injector masking the problem?

The car does have the 81-up airbox with popoff valve so I'm not anticipating an explosion...


Thanks again,
Doug

[Wayne 962]

The pressure drops, and then vapor lock ensues. Check the fuel pressure between the accumulator and the check valve...

-Wayne

[Pettybird]

Great-

Thanks a lot... I'll get to it in a couple weeks when I'm home for spring break.

Doug

[Groesbeck Hurricane]

Did not have time to get back on her this weekend. Had to repair some fence line and take down a couple of large trees that were threatening the house.

Rob, Doug, Wayne,

Thanks for the thoughts. It seems that everyone feels it is a fuel problem. I'm ordering a new accumulator today (I know your supposed to diagnose then replace but I feel the accumulator is the most likely suspect with what I've read and the general gist of this thread and I want to get back in the car soon!) and will put in when it arrives. The car starts up fine now and runs well.

I did replace hoses, rubber when I did the re-build. But, who is to say the new ones are not leaking? I'll do a visual inspection on them and see if I can isolate anything.

I also feel that I need to get the fuel mixture correct. Just hate to spend money as the wife and I are building a new home. My babies got a 15 X 40 bay for herself and a Model A. Should be a neat mix...

I'll re-post when I get done checking. Thanks to all!!!!

[Superman]

CIS problems do not cause oil pressure gauges to read "0." And besides, CIS troubleshooting is done AFTER ignition is dealt with. I say focus on electrical first. Perhaps there is a plug somewhere that acts up.

[Groesbeck Hurricane]

All,

I checked all the connections I could reach, all good. All the hoses looked nice but the air filter was dirty. I replaced the fuel accumulator and bled the system. I also (I know this is the wrong way but I know the mixture was rich) leaned the mixture two places.

The old accumulator did not prevent me blowing backwards on it. There was very little resistance.

I finally got time tonight and turned her over. Started right up, four small backfires while she tried to die. Never died but I did run her for 90 seconds at 2,000 RPM. Let her go to normal idle and she dropped to 950 and stayed. Ran nice. I left her running for 15 minutes and no issues, no backfires, steady idle everytime I checked.

Hope to have more time soon to do more trouble shooting on the CIS.

[vash]

i cost me $49 dollars to have a mechanic set my airfuel mixture.

cliff