Novak Conversions Jeep Wrangler YJ engine mounts

YJ runs fine for 10-20 miles, then hesitates, sputters, and stalls

T-Rex Jeepster said:
Haven't read through the replies....But it could be that when the engine compartment gets hot...It's breaking down a weak coil..........
Click to expand...

Its defiantly something about what the engine bay gets hot. I will bench test my current coil when I get time (cold and hot)
But being that it usually will restart and idle right away I have a feeling that's not the issue. Also, this being the third coil, all different brands from different stores in 2 different states. As I said, I will test it, just in case I got 2 bad coils out of the box.
 
Zimic said:
Hey Ralph,

Sorry to hear your having the same pain in the A as me. Although it does make me feel more sane that I'm not the only one with this problem. I haven't been able to do more troubleshooting on mine for the last week but will try to get on it soon. I had some of the same issue I would pull off a part and see corrosion or something and think I found it but nope. I do have a very extensive set of back up parts unfortunately.
If I figure anything out, I will post it here. I would appreciate you doing the same. Maybe one of us will have some good luck soon.
Click to expand...
Hi,
The truth is I haven't had much time to work on my Jeep either, it is bass fishing season. I will post any thing I do/find. I was thinking about it last night and I think my next move will be to install my fuel pressure gauge and tape it to the hood so I can see what happens as it stalls. At least it will point me to the right system.
 
Zimic said:
Its defiantly something about what the engine bay gets hot. I will bench test my current coil when I get time (cold and hot)
But being that it usually will restart and idle right away I have a feeling that's not the issue. Also, this being the third coil, all different brands from different stores in 2 different states. As I said, I will test it, just in case I got 2 bad coils out of the bo
Click to expand...
I understand now, it will fire back up, then shuts down again. That will be hard to diagnose, best of luck.
 
Zimic said:
Its defiantly something about what the engine bay gets hot. I will bench test my current coil when I get time (cold and hot)
But being that it usually will restart and idle right away I have a feeling that's not the issue. Also, this being the third coil, all different brands from different stores in 2 different states. As I said, I will test it, just in case I got 2 bad coils out of the box.
Click to expand...

Electricals are NOTORIOUS for being bad out of the box....Thats why parts houses will exchange but not refund.....That being said, I think the odds of getting three new/bad are really high. Did you check/replace your fuel filter? Might have to go as far as pulling your tank and looking for trash or a clogging pickup filter. The reason I asked if you checked your fuel line routing, Could be somehow the steel part of it that comes up from the frame into the motor compartment has come loose from the frame and is close enough proximity to the exhaust to create a vapor lock....
 
Here's something that happened to me although it didn't shut down the engine. My charcoal canister (emissions) was restricting the vapor return line from the gas tank such that I could fill the gas tank at a normal speed, only super slow. Mine is a 1988 with a 20 gal plastic tank. You might try either pulling that vapor line from the canister or even easier, remove the gas cap for a short run/experiment (with not a full tank).
 
T-Rex Jeepster said:
Electricals are NOTORIOUS for being bad out of the box....Thats why parts houses will exchange but not refund.....That being said, I think the odds of getting three new/bad are really high. Did you check/replace your fuel filter? Might have to go as far as pulling your tank and looking for trash or a clogging pickup filter. The reason I asked if you checked your fuel line routing, Could be somehow the steel part of it that comes up from the frame into the motor compartment has come loose from the frame and is close enough proximity to the exhaust to create a vapor lock....
Click to expand...
thanks,
I've replaced every filter including the one in the tank and inspected the tank while i had it out and all the fuel lines. It was amazingly clean for being over 30 years old, no contaminants in the tank.
 
  • Like
Reactions: T-Rex Jeepster
swanny71 said:
Here's something that happened to me although it didn't shut down the engine. My charcoal canister (emissions) was restricting the vapor return line from the gas tank such that I could fill the gas tank at a normal speed, only super slow. Mine is a 1988 with a 20 gal plastic tank. You might try either pulling that vapor line from the canister or even easier, remove the gas cap for a short run/experiment (with not a full tank).
Click to expand...
will try
 
Zimic said:
Its defiantly something about what the engine bay gets hot. I will bench test my current coil when I get time (cold and hot)
But being that it usually will restart and idle right away I have a feeling that's not the issue. Also, this being the third coil, all different brands from different stores in 2 different states. As I said, I will test it, just in case I got 2 bad coils out of the box.
Click to expand...
Have you figured anything out. I have the same symptom. Once the engine is at normal temperature if I'm just idleing around slow in the pasture it starts to idle very rough. Once I get out on the road and drive faster I can slow back to an idle and it's fine. But within a couple of minutes it goes rough again. I suspect that something is getting hot in the engine compartment when I'm stopped or drive slow.
 
Richardk said:
Have you figured anything out. I have the same symptom. Once the engine is at normal temperature if I'm just idleing around slow in the pasture it starts to idle very rough. Once I get out on the road and drive faster I can slow back to an idle and it's fine. But within a couple of minutes it goes rough again. I suspect that something is getting hot in the engine compartment when I'm stopped or drive slow.
Click to expand...
Unfortunately, nothing has changed. Other than firing it up and taking it for a short drive now and then, it's been sitting. I had to put it on the back burner while I work on more pressing projects. I hope to get back to it soon, I will update here if or when I figure anything out.
 
Zimic said:
Unfortunately, nothing has changed. Other than firing it up and taking it for a short drive now and then, it's been sitting. I had to put it on the back burner while I work on more pressing projects. I hope to get back to it soon, I will update here if or when I figure anything out.
Click to expand...
I'm having a similar issue... it starts a little rough but then idles great... when i pull off it bucks and lurches.
If I stand on the accelerator it pulls fine but if I try to operate at a moderate pace it bucks again... I can hurry thru the gears till about fourth and it smooths out but mostly I think because I'm giving it more throttle...
I really need to figure it out. I have big plans for the ole girl but those plans are futile if it won't drive decent
 
rgirardi said:
Hi,
The truth is I haven't had much time to work on my Jeep either, it is bass fishing season. I will post any thing I do/find. I was thinking about it last night and I think my next move will be to install my fuel pressure gauge and tape it to the hood so I can see what happens as it stalls. At least it will point me to the right system.
Click to expand...
Put a fuel pressure gauge in line before the carb (Webber) and now I haven't had the issue since. My luck always, runs great but I can drive around with a gage on my windshield, lol.
 
T-Rex Jeepster said:
Haven't read through the replies....But it could be that when the engine compartment gets hot...It's breaking down a weak coil..........
Click to expand...
Don't discount this possibility ! take your coil off and shake it. Mine rattled and I replaced it. Also I haven't seen anyone suggest checking Vaccum , If you don't have a gauge..... take a picture of the throttle body where all the Vaccum lines connect. Leave the fuel pressure regulator and the MAP connected ,plug off all the ports on the throttle ( golf tees work good for this ) If it runs better connect the lines back up until it starts cutting out again. A quick version of this test would be to disconnect and plug off the hose that goes to the PCV Valve, it could be plugged up.....Good Luck
 
Last edited:
  • Like
Reactions: T-Rex Jeepster
Have no idea if this is related, but I'll throw it out there. I was having extreme trouble filling with gas at the gas station, had to fill super slow out it was tripping the automatic gas pump shut-off. Turned out to be the emissions evaporator canister was clogged which didn't allow venting of the fuel vapor pressure while filling with gas. The charcoal inside was fine, it was the foam pieces they used at the inlet/outlets that became clogged. These are sealed system designs especially in California.
I would say since you have good fuel pressure, then the gas tank must not be building up a vacuum to prevent fuel flow (mine wasn't that bad yet). An easy test would be to try driving it with the gas cap loosened (but not with a full tank).
 
swanny71 said:
Have no idea if this is related, but I'll throw it out there. I was having extreme trouble filling with gas at the gas station, had to fill super slow out it was tripping the automatic gas pump shut-off. Turned out to be the emissions evaporator canister was clogged which didn't allow venting of the fuel vapor pressure while filling with gas. The charcoal inside was fine, it was the foam pieces they used at the inlet/outlets that became clogged. These are sealed system designs especially in California.
I would say since you have good fuel pressure, then the gas tank must not be building up a vacuum to prevent fuel flow (mine wasn't that bad yet). An easy test would be to try driving it with the gas cap loosened (but not with a full tank).
Click to expand...
excellent suggestion
 
BUENOS DÍAS, HERMANO. TENIA UN PROBLEMA SIMILAR EN MI YJ 87 CON MOTOR 258 A CARBURADOR, ARRANCO CON FALLA DE CORRIENTE EN LA BUJIA Y SE FALLABAN DE 2 A 3 CILINDROS CADA 10 KM, APAGUE EL CARRO Y LO VOLVI A ENCENDER Y SE CORREGIO POR OTRO KM MAS LO CONSIGUE CAMBIE TODOS LOS CABLES BUJIAS TAPA DISTRIBUIDOR MODULO TODA LA BOBINA Y SEGUI EL PROBLEMA HASTA QUE UN MECANICO DE CONFIANZA LO REVISO Y ERA EL ARBOL DE LEVAS Y LOS TAPPERS DESGASTADOS, REVISE ESO A VER SI ES EL MISMO PROBLEMA
 
I'm having the same issues. I put a new hei distributor and weber 32 36 carburetor plugs wires. Rear main seal timing chain. 90 yj 4.2 manual. Once it's warm she dies easy. Fires right back up then dies. Please help. Running out of things to replace
 
Novak Conversions Jeep Wrangler YJ engine mounts
Top Bottom