Ok, got my #3 exhaust stud removed and my leak fixed. Cost about $300 clams as I had thought. Now I have a brand new problem, when I hit 4k RPM the car stumbles and has sort of a "clack, clack" sound as long as I am on the gas. Almost as if it's a back fire. I have quite a few parts to swap out if need be but looking for suggestions from those who have had similar problems. It starting doing this right after I picked it up from the shop. It wasn't like this on monday when I dropped it off. Any chance I burned the #3 valve on the way to the shop?
Engine is a 74 2 liter Fuel Injected.
Luke
Full Version: 4k RPM Stumble and weird sound
check the clearance (maybe all of 'em) before you jump to conclusions.
!!UPDATE!!
more specific syptoms.
Took the car for a drive and here is what I descovered, all of this is while driving and under a load.
1. I mash the pedal to about 3/4-full in second/third and hold it, when it hits 4k-4.1K RPM its stumbles and makes that faint back fire noise.
2. If I hold the pedal at about 1/2 (or lower) in second/third gear it will slowly make it's way to 4k-4.1k and past that with out stumbling.
I want to think it's the TPS but it only does it past 4k RPM regardless of where the pedal is and therefore regardless of where the TPS is at at that given pedal location. I would assume that if it was the TPS then it would stumble the minute I had the throttle past 1/2 way.
I checked all my connections on the TPS, MPS and Fuel Injectors. I also checked the spark plug wires on both ends. If I unplug the TPS and it runs the same does it rule it out?
THe car runs amazing since the the #2 valve and #3 exhaust leak was fixed. It has great power up until the 4k mark.
Sorta at a loss as to where to start.
LukeD
more specific syptoms.
Took the car for a drive and here is what I descovered, all of this is while driving and under a load.
1. I mash the pedal to about 3/4-full in second/third and hold it, when it hits 4k-4.1K RPM its stumbles and makes that faint back fire noise.
2. If I hold the pedal at about 1/2 (or lower) in second/third gear it will slowly make it's way to 4k-4.1k and past that with out stumbling.
I want to think it's the TPS but it only does it past 4k RPM regardless of where the pedal is and therefore regardless of where the TPS is at at that given pedal location. I would assume that if it was the TPS then it would stumble the minute I had the throttle past 1/2 way.
I checked all my connections on the TPS, MPS and Fuel Injectors. I also checked the spark plug wires on both ends. If I unplug the TPS and it runs the same does it rule it out?
THe car runs amazing since the the #2 valve and #3 exhaust leak was fixed. It has great power up until the 4k mark.
Sorta at a loss as to where to start.
LukeD
TPS only really affects idle.
Sounds like ignition, but check the compression and the valve adjustment first since you have changed things in that general area.
Sounds like ignition, but check the compression and the valve adjustment first since you have changed things in that general area.
Rule out the TPS...disconnect it and see if the stumble persists.
BTW I am having the same problem, maybe my car gave your car a virus
Who did you take your car too?
BTW I am having the same problem, maybe my car gave your car a virus
Who did you take your car too?
Kelly, once again thank you for all your help with getting my engine back in 
I used to use Speed Unlimited on Olive but I got tired of the guy telling me that I needed to ditch the FI and put on carbs, that and he kept refering to my engine as a bus motor. I tried to explain the differences and he is just old and thinks he's right. Anyway...
I use Siegfred's Motors on Blackstone in between Bullard and Sierra on the west side of the street. Been around a long time and have older mechanics. They have a bunch of 9 elebens, 944's, mercedes, BMW's and such around the shop, and the owner "Siegfred" is very pleasant to talk to, as well as liking the 914's. HE worked on my exhaust stud personally and I ended up taking 3 starbucks cards along with me when i picked it up. They are pretty reasonable, cost me $300 for the stud and they had it 2 days, $85 for a valve adjustment last time I took it there, I think it's $85 hour in general. However, I am not sure how knowledgeable they are when it comes to the FI on these cars, I am not sure I want to find out the money way either, but I might have to if I can't solve it.
Lukster
I used to use Speed Unlimited on Olive but I got tired of the guy telling me that I needed to ditch the FI and put on carbs, that and he kept refering to my engine as a bus motor. I tried to explain the differences and he is just old and thinks he's right. Anyway...
I use Siegfred's Motors on Blackstone in between Bullard and Sierra on the west side of the street. Been around a long time and have older mechanics. They have a bunch of 9 elebens, 944's, mercedes, BMW's and such around the shop, and the owner "Siegfred" is very pleasant to talk to, as well as liking the 914's. HE worked on my exhaust stud personally and I ended up taking 3 starbucks cards along with me when i picked it up. They are pretty reasonable, cost me $300 for the stud and they had it 2 days, $85 for a valve adjustment last time I took it there, I think it's $85 hour in general. However, I am not sure how knowledgeable they are when it comes to the FI on these cars, I am not sure I want to find out the money way either, but I might have to if I can't solve it.
Lukster
No sweat Luke I had a good time
There is an autox in sept at millerton and then the zone 7 one in october.
if you dont drive in itthe weather might be good enough to check it out.
There is an autox in sept at millerton and then the zone 7 one in october.
if you dont drive in itthe weather might be good enough to check it out.
!! UPDATE !!
Ok, new info. I replaced my MPS with know good one, replaced my sparkplugs and cap as the old looked crappy. Problem still persists. However, I have norrowed it down even more.
The car runs good and pulls hard for about 2-5 minutes of driving when the engine is cold. After that it starts to hesitate at at about 3800 and kinda back fires. Car idles fine seems to run fine until I put my foot in it a little. If I give 1/4 throttle it will pull past 4k no prob but as soon as a stomp it it pulls hard all the way to 3800-4k and starts to stumble a bit.
I am out idea's
Maybe my fuel filter is clogged
maybe my electronic points are going bad? My spark plugs were all sorta white (lean?)
Luke
Ok, new info. I replaced my MPS with know good one, replaced my sparkplugs and cap as the old looked crappy. Problem still persists. However, I have norrowed it down even more.
The car runs good and pulls hard for about 2-5 minutes of driving when the engine is cold. After that it starts to hesitate at at about 3800 and kinda back fires. Car idles fine seems to run fine until I put my foot in it a little. If I give 1/4 throttle it will pull past 4k no prob but as soon as a stomp it it pulls hard all the way to 3800-4k and starts to stumble a bit.
I am out idea's
Maybe my fuel filter is clogged
maybe my electronic points are going bad? My spark plugs were all sorta white (lean?)Luke
!! UPDATE !!
Problem has been found but I brings another question
I just put my engine back in because of a bad valve guide on the #2 exhaust valve. Well, the #2 spark plug wire, as I was taking it out of the cap for about the 5th time, broke off at the boot and green powder fell out (same crap that grows on a battery). I replace the wire with a good used one and the problem apears to be gone. Would this bad wire, over a long period of time, have caused my valve guide to wear prematurely? It seams a bit coincidental that the same thing that has been causing my stumbling is on the same cylinder as my bad valve giude.
Luke
Problem has been found but I brings another question
I just put my engine back in because of a bad valve guide on the #2 exhaust valve. Well, the #2 spark plug wire, as I was taking it out of the cap for about the 5th time, broke off at the boot and green powder fell out (same crap that grows on a battery). I replace the wire with a good used one and the problem apears to be gone. Would this bad wire, over a long period of time, have caused my valve guide to wear prematurely? It seams a bit coincidental that the same thing that has been causing my stumbling is on the same cylinder as my bad valve giude.
Luke
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