In reply to Curtis73 :
The system is non-existent on the car and the port is plugged.
In reply to Curtis73 :
The system is non-existent on the car and the port is plugged.
I need to do some digging and some verification, but after rebuilding the carb and having no results I dicked around with the ports and I am 95% sure that the EGR port is ported vacuum and the DIS port is manifold vacuum. I have 0" at the EGR port, as I rev it the vacuum ramps up nicely.
That in mind, let's start over.
I have a flat spot with the carb, it is nowhere near as bad as it used to be, now it acts closer to what my old Holley did when the accelerator pump was not adjusted properly. Tries to rev and stumbles, but you can hear that the engine is still running (as opposed to the previous issue) I've done some preliminary adjustment of the pump with no results, I'm thinking that for now I'll reinstall the original jet that came with it and see where I'm at.
If you're certain it's carb-related, take the shortcut. Junkyard carb, ghetto rebuild, bolt it on and see if it's different. Contrary to popular belief, don't stress about new gaskets and things. Pull the horn off, jet things out with brake cleaner, scrub crusty stuff, lube up the accelerator pump with oil, reassemble.
I'm not certain of anything, but I don't know what else I can do with the ignition now that it's set at 0"
Worth trying to adjust vacuum till it is just gets out of 0" and then dial it back to that? Right now it may be setup too low.
Mr_Asa said:I need to do some digging and some verification, but after rebuilding the carb and having no results I dicked around with the ports and I am 95% sure that the EGR port is ported vacuum and the DIS port is manifold vacuum. I have 0" at the EGR port, as I rev it the vacuum ramps up nicely.
Sounds logical. All EGRs are designed to operate on ported vacuum so they are inoperative at idle and WOT.
If the DIS port is manifold and you're only getting 8-9" vacuum, you either have A) carb with too much throttle and/or B) ignition timing retarded, C) vacuum leak, or D) cam problems; not timed properly, wiped lobe(s), collapsed lifters. Other problems could be causing it, but I didn't see or hear any evidence of it from the video. Things like a valve stuck open (would cause a major misfire), cracked ring (would likely show up as massive clouds of blue smoke) or bad head gasket (which would likely cause both a misfire and smoke).
... or a broken vacuum gauge.
A stock cam in that engine should make 12" with a terrible tune and 15" with a proper tune. If you weren't in central FL, I'd come over tomorrow and dive in.
Mr_Asa said:I'm not certain of anything, but I don't know what else I can do with the ignition now that it's set at 0"
Worth trying to adjust vacuum till it is just gets out of 0" and then dial it back to that? Right now it may be setup too low.
Sorry... confused.... 0" or zero degrees?
Since your dizzy vacuum port is manifold, here is how I would set it up.
Start engine
yank vacuum line and plug it. Adjust idle to keep it running if necessary
Advance timing until you get to 12-ish degrees initial.
reconnect vacuum.
Back down idle until you get to idle spec, or until you get to max vacuum.
If you do that and don't get rid of the bog, let me know.
Fairly certain the gauge is good. I had it on my truck for a little bit. It seems to rest just above 0 (it's a vacuum/boost gauge) but there also seems to be a range where it says its at 0 as opposed to the rest of the ranges where its a regular incremental change.
The opening in the throttle plate may not be sized for a 200ci, but other than that I don't know that any of those would be a viable problem. I'll go through and see if I can find a vacuum leak, but as I said its hard to have vacuum leaks in this system just because of how its designed. A problem with the lifters might be the next most possible issue, God knows how many miles are actually on the engine, and I have had mild valve-train issues before. I wouldn't be surprised if there was one that was trying to collapse.
With the weirdness I've seen with the ports, I wouldn't be surprised if the DIS port was something halfway between manifold and ported vacuum. That might be the most likely possibility.
Curtis73 said:Mr_Asa said:I'm not certain of anything, but I don't know what else I can do with the ignition now that it's set at 0"
Worth trying to adjust vacuum till it is just gets out of 0" and then dial it back to that? Right now it may be setup too low.
Sorry... confused.... 0" or zero degrees?
Since your dizzy vacuum port is manifold, here is how I would set it up.
Start engine
yank vacuum line and plug it. Adjust idle to keep it running if necessary
Advance timing until you get to 12-ish degrees initial.
reconnect vacuum.
Back down idle until you get to idle spec, or until you get to max vacuum.If you do that and don't get rid of the bog, let me know.
0", not degrees
I pulled the vacuum line and plugged it with the vacuum gauge, set idle to stock recommended.
Set timing, reconnected vacuum line. Did not have vacuum gauge hooked up at this time, I'll try and dig up a t-connector so I can have gauge and advance.
In reply to Mr_Asa :
FYI, Maxpeedingrods sells a YF carb.
In reply to Curtis73 :
Well that didn't work.
b13990 said:In reply to Mr_Asa :
FYI, Maxpeedingrods sells a YF carb.
That's a stupidly cheap carb. It bothers me that its listed as a YF instead of a YFA
Ok, I have no clue what's going on, but I have no flat spot now, instead the engine has a backfire out the carb. Timing is on 12 degrees at idle.
Car revs beautifully, just it sometimes backfires.
Solid lifters or hydraulic?
If the valves are a little too tight you can get a sneeze out of the carb.
Carbon tracking inside the distributor cap or arcing through the wires can cause this too.
Hydraulic. I probably do need to check the rotor and cap.
You'll need to log in to post.
