I am about to give up...
6/24/08, 12:01 PM
#1
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I am about to give up...
I have a problem with the 84. I cannot figure it out.
A few weeks ago, it started surging and bucking during cruise and you could feel it doing the same when accelerating. So, I have...
Replaced fuel filter
Replaced plugs, cap, rotor
Replaced Fuel pump (went to Holley red)
Replaced carburetor (with same type and configuration)
Replaced Duraspark ignition control module
Replaced ignition coil pickup in distributor (Duraspark)
Replaced coil
Bumped timing a bit
Sprayed around intake with carb cleaner listening for idle change to denote leak
I did also find that the vacuum advance on the distributor was wasted and ordered one of those to pick up and put on this afternoon.
And I have had almost no luck except for very small changes. I guess the only thing that is left is the plug wires. I put a fuel pressure gauge on and you can see it bouncing and keeping up around 6PSI. When I shut the car off, it goes immediately to zero. That's kinda strange, but I guess that is how it works, right? Or is that a symptom? I kinda figured it should hold at 6 and possibly slowly drop down. It did used to slowly bleed down before I replaced the pump.
I am stumped and getting to the point where I am not having any fun. Any suggestions? Have I done wrong overlooking fuel volume? I wouldn't think so. I can sit and rev to 3500RPM and the pressure is still there, so it must be keeping the bowl full. Right now, I do not know if I am chasing an ignition or a fuel problem since they are so close.
Any suggestions welcome.
A few weeks ago, it started surging and bucking during cruise and you could feel it doing the same when accelerating. So, I have...
Replaced fuel filter
Replaced plugs, cap, rotor
Replaced Fuel pump (went to Holley red)
Replaced carburetor (with same type and configuration)
Replaced Duraspark ignition control module
Replaced ignition coil pickup in distributor (Duraspark)
Replaced coil
Bumped timing a bit
Sprayed around intake with carb cleaner listening for idle change to denote leak
I did also find that the vacuum advance on the distributor was wasted and ordered one of those to pick up and put on this afternoon.
And I have had almost no luck except for very small changes. I guess the only thing that is left is the plug wires. I put a fuel pressure gauge on and you can see it bouncing and keeping up around 6PSI. When I shut the car off, it goes immediately to zero. That's kinda strange, but I guess that is how it works, right? Or is that a symptom? I kinda figured it should hold at 6 and possibly slowly drop down. It did used to slowly bleed down before I replaced the pump.
I am stumped and getting to the point where I am not having any fun. Any suggestions? Have I done wrong overlooking fuel volume? I wouldn't think so. I can sit and rev to 3500RPM and the pressure is still there, so it must be keeping the bowl full. Right now, I do not know if I am chasing an ignition or a fuel problem since they are so close.
Any suggestions welcome.
6/24/08, 12:38 PM
#3
legacy Tms Member
automatic or stick .. automatic do a brake stand and bad wires will miss ,, stick do a high gear pull from low speed and motor will miss from wires breaking down ..
6/24/08, 12:55 PM
#4
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Good suggestions.
Hoss, sorry 'bout that. Forgot to tell.
86 5.0 block with E7 ported heads, Edelbrock Performer intake, Holley 600 carb with vacuum secondaries, Hooker SuperComp shorties with offroad H and duals, T5 transmission.
Mark, sounds like an idea.
Hoss, sorry 'bout that. Forgot to tell.
86 5.0 block with E7 ported heads, Edelbrock Performer intake, Holley 600 carb with vacuum secondaries, Hooker SuperComp shorties with offroad H and duals, T5 transmission.
Mark, sounds like an idea.
6/24/08, 06:34 PM
#5
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don't give up...nobody likes a quitter.....did General Washington quit before he crossed the icy waters of the Mississippi? Did General Ulysses S. Grant give up when he was surrounded by Lee at the Alamo? Did the Mets give up two seasons ago when they were up 13 games with 15 left to play? No! You can do it and I have faith in you....more faith than anyone else on this site, so remember that on my birthday....which is in december
6/24/08, 07:22 PM
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don't give up...nobody likes a quitter.....did General Washington quit before he crossed the icy waters of the Mississippi? Did General Ulysses S. Grant give up when he was surrounded by Lee at the Alamo? Did the Mets give up two seasons ago when they were up 13 games with 15 left to play? No! You can do it and I have faith in you....more faith than anyone else on this site, so remember that on my birthday....which is in december
"Germans?"
"Let him go. He's on a roll"
"Who's with me? AHHHHHHHHHHHHHH"
6/24/08, 07:32 PM
#9
legacy Tms Member
my truck drove me nuts with a cruise/part throttle miss for the first year i owned it .. tyied everything there was that was removeable .. finally one day it would`nt start .. dirty battery cable .. fixed the cable and the miss went away ...thats now how i know when my cables need cleaning .. if i pick up a part throttle miss. .. and i was there at custers last stand at woodstock in 69
Last edited by HOSS429; 6/24/08 at 07:35 PM.
6/24/08, 07:55 PM
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You didnt seem to be having any problem when you WOT out of the post office parking lot today.. hehehe
My guess would have been the vac-advance but you said you replaced it. Just for the heck of it you can check/clean or replace the ground wires.. When you get tired of messing with it, I'll buy it from you.
If you want to work on someone elses rather than yours. You can show me how to fix these dang quarter windows. The cogs are all worn down.
My guess would have been the vac-advance but you said you replaced it. Just for the heck of it you can check/clean or replace the ground wires.. When you get tired of messing with it, I'll buy it from you.
If you want to work on someone elses rather than yours. You can show me how to fix these dang quarter windows. The cogs are all worn down.
6/25/08, 07:00 AM
#12
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*laughs*
Keep, I don't remember being WOT out of there. Part, yes. WOT and the thing rattles more than spray paint can and belches enough black smoke to kill mosquitoes for miles. The vacuum advance has helped a bunch. I still think it is running a bit lean and it does not want to idle down. I think I will take the other carb and put two sizes bigger jets in it and see what happens. the grounds are all great. Everything was cleaned/replaced back last September. Keep, I can show you easily how to fix those quarter motors. I also know where you buy some used ones that have had the rollers replaced. :-)
Lennyb44 - It is good. I even disconnected it and plugged the vacuum port to test. I have also plugged the vacuum to the brake booster. I had no vacuum ports open at one time.
I am still wondering about the fuel pressure dropping to zero immediately at shut-off. Does the Holley red do this? Or is this a symptom of an issue?
Thanks everyone.
Keep, I'll keep you in mind when I sell it. I am very close right now.
Oh, wait, with it getting 20MPG, I think I will keep it.
Keep, I don't remember being WOT out of there. Part, yes. WOT and the thing rattles more than spray paint can and belches enough black smoke to kill mosquitoes for miles. The vacuum advance has helped a bunch. I still think it is running a bit lean and it does not want to idle down. I think I will take the other carb and put two sizes bigger jets in it and see what happens. the grounds are all great. Everything was cleaned/replaced back last September. Keep, I can show you easily how to fix those quarter motors. I also know where you buy some used ones that have had the rollers replaced. :-)
Lennyb44 - It is good. I even disconnected it and plugged the vacuum port to test. I have also plugged the vacuum to the brake booster. I had no vacuum ports open at one time.
I am still wondering about the fuel pressure dropping to zero immediately at shut-off. Does the Holley red do this? Or is this a symptom of an issue?
Thanks everyone.
Keep, I'll keep you in mind when I sell it. I am very close right now.
Oh, wait, with it getting 20MPG, I think I will keep it.
6/25/08, 05:02 PM
#14
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Well, not only do I now have an extra carb, as Mark pointed out to someone else, I have a NEW carb.
I'm gonna buy some jets, a 4150 conversion kit, and maybe one of these...
http://www.jegs.com/p/Holley/745181/10002/-1/10625
I'm gonna buy some jets, a 4150 conversion kit, and maybe one of these...
http://www.jegs.com/p/Holley/745181/10002/-1/10625
6/25/08, 05:34 PM
#15
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Ralph,
If you want, come get my book of matches and gas can. I've been tempted to use it on mine a few times over the years...
Guaranteed to solve your problem.
I know my car is FI, but it used to drop to 0 fp once I killed the engine. The diaphragm in the fuel pressure regulator was bad. Replaced the regulator and it fixed the problem. There were a few driveability problems at the time and I am not sure if that was the cause. I want to say it lead to some hard starts.
Also, mine used to buck and surge ever so slightly at cruise speed 60-65. Disconnected and plugged the vacuum port on the EGR. Unmetered air was the culprit.
I'm pretty sure none of that applies to your car, but when you are at your wit's end, you'll listen to anything.
Casey
If you want, come get my book of matches and gas can. I've been tempted to use it on mine a few times over the years...
Guaranteed to solve your problem.
I know my car is FI, but it used to drop to 0 fp once I killed the engine. The diaphragm in the fuel pressure regulator was bad. Replaced the regulator and it fixed the problem. There were a few driveability problems at the time and I am not sure if that was the cause. I want to say it lead to some hard starts.
Also, mine used to buck and surge ever so slightly at cruise speed 60-65. Disconnected and plugged the vacuum port on the EGR. Unmetered air was the culprit.
I'm pretty sure none of that applies to your car, but when you are at your wit's end, you'll listen to anything.
Casey
6/26/08, 08:57 AM
#16
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Good to see you around here Casey...
The fuel pressure just has me scratching my head. On the old pump, I remember the pressure bleeding down. And I *thought* that the Holley red did this when I first put it on a couple of weeks ago. I figure that the Holley should have some sort of check valve in it to keep this from happening. And, yes, I did make darn sure that I hooked it up in the proper direction (in -> out).
I plugged my PCV this morning. That also seemed to have helped. My idle dropped down to 500 now. Oops. I also need to do a minor adjustment to the new Holley (accelerator pump a hair loose). I still want to throw jets two sizes larger in it and see what happens. Plugs are white.
I just want to go home and do something else besides work on the car for a change. *grins*
The fuel pressure just has me scratching my head. On the old pump, I remember the pressure bleeding down. And I *thought* that the Holley red did this when I first put it on a couple of weeks ago. I figure that the Holley should have some sort of check valve in it to keep this from happening. And, yes, I did make darn sure that I hooked it up in the proper direction (in -> out).
I plugged my PCV this morning. That also seemed to have helped. My idle dropped down to 500 now. Oops. I also need to do a minor adjustment to the new Holley (accelerator pump a hair loose). I still want to throw jets two sizes larger in it and see what happens. Plugs are white.
I just want to go home and do something else besides work on the car for a change. *grins*
6/26/08, 09:26 AM
#17
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Good to see you around here Casey...
The fuel pressure just has me scratching my head. On the old pump, I remember the pressure bleeding down. And I *thought* that the Holley red did this when I first put it on a couple of weeks ago. I figure that the Holley should have some sort of check valve in it to keep this from happening. And, yes, I did make darn sure that I hooked it up in the proper direction (in -> out).
I plugged my PCV this morning. That also seemed to have helped. My idle dropped down to 500 now. Oops. I also need to do a minor adjustment to the new Holley (accelerator pump a hair loose). I still want to throw jets two sizes larger in it and see what happens. Plugs are white.
I just want to go home and do something else besides work on the car for a change. *grins*
The fuel pressure just has me scratching my head. On the old pump, I remember the pressure bleeding down. And I *thought* that the Holley red did this when I first put it on a couple of weeks ago. I figure that the Holley should have some sort of check valve in it to keep this from happening. And, yes, I did make darn sure that I hooked it up in the proper direction (in -> out).
I plugged my PCV this morning. That also seemed to have helped. My idle dropped down to 500 now. Oops. I also need to do a minor adjustment to the new Holley (accelerator pump a hair loose). I still want to throw jets two sizes larger in it and see what happens. Plugs are white.
I just want to go home and do something else besides work on the car for a change. *grins*
6/28/08, 05:39 PM
#18
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Okay, I worked on it today. Looked at the old carb and it has 65 jets in the primary and a 134-39 plate in the secondary. The new one has 64 jets and same plate.
I got some 68s and put them in the old. Tested. Hmmm... better. Swapped them into the new one. Better. Still have a funny issue when shifting that seems to be the accelerator pump on the new one. Like it "dies" for a split second. Change out the accelerator diaphragm and the squirter. Both have 31 squirters, but the old one has extensions on it. Re-adjusted the accelerator. Helped a little. May have to look at getting a bigger squirter.
Still breaking up at 4K RPM and above. I'm gonna go ahead and replace the 9-year-old wires and swap in a metering block for the secondaries. Holley shows the relevant jet size for that plate to be a 69, so I am getting a kit of jets that go 70-80.
Still does not want to start all when hot. *smirks* Not sure I have the room to go with a phenolic spacer.
This all started right after a fillup one night. Now, I know they have been putting ethanol in the gas, but I have tried buying from several places. Maybe there is a big influx of ethanol in the stuff.
I got some 68s and put them in the old. Tested. Hmmm... better. Swapped them into the new one. Better. Still have a funny issue when shifting that seems to be the accelerator pump on the new one. Like it "dies" for a split second. Change out the accelerator diaphragm and the squirter. Both have 31 squirters, but the old one has extensions on it. Re-adjusted the accelerator. Helped a little. May have to look at getting a bigger squirter.
Still breaking up at 4K RPM and above. I'm gonna go ahead and replace the 9-year-old wires and swap in a metering block for the secondaries. Holley shows the relevant jet size for that plate to be a 69, so I am getting a kit of jets that go 70-80.
Still does not want to start all when hot. *smirks* Not sure I have the room to go with a phenolic spacer.
This all started right after a fillup one night. Now, I know they have been putting ethanol in the gas, but I have tried buying from several places. Maybe there is a big influx of ethanol in the stuff.
6/28/08, 08:59 PM
#19
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There are more and more stations using ethanol everyday. I have not had any issues in my stang but the wife's car does not like it at all. After I ran some gas without the ethanol through it, the car started acting right again.
6/30/08, 10:20 AM
#20
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You know, I started having issues last week driving the old vert. Stumbling on corners and not wanting to start mid day. Drives fine other than that, but I never see anything north of 4krpm
Must be the gas.
Must be the gas.