Another FJ60 hesitation/stutter/hard to start when warm thread (1 Viewer)
- Thread starter Rube
- Start date
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tmxmotorsports
SILVER Star
It looks like you can just ground the wire to test. The temp sensor shows it goes to ground.
- Thread starter
- #23
So the sage continues this morning. Fairly sure my attempts to problem solve have not been the most efficient to date. Few issues this morning.
#1. Wire color discrepancy. Per the FSM and my truck, the wire coming of of the cooling fan relay and going to the thermistor (I currently have grounded to the fender) should in fact be blue. Mine is blue when it leaves the relay but what exits the wiring loom under hood seems to be black. I swear this is what I've spliced into before. The wire comes out with the 2 for the carburator. Picture below.
#2 In looking at the relay diagram (I am purely novice) and attempting to understand it, am I correct in thinking that if I simply unhooked the cooling fan relay and then took the relay fan connector & grounded the connections leaving from the blue and white wires, that I should then be able to essentially just add a jumper wire from the green to the red/black wire and have the carb fan at least function albeit untimed?
#1. Wire color discrepancy. Per the FSM and my truck, the wire coming of of the cooling fan relay and going to the thermistor (I currently have grounded to the fender) should in fact be blue. Mine is blue when it leaves the relay but what exits the wiring loom under hood seems to be black. I swear this is what I've spliced into before. The wire comes out with the 2 for the carburator. Picture below.
#2 In looking at the relay diagram (I am purely novice) and attempting to understand it, am I correct in thinking that if I simply unhooked the cooling fan relay and then took the relay fan connector & grounded the connections leaving from the blue and white wires, that I should then be able to essentially just add a jumper wire from the green to the red/black wire and have the carb fan at least function albeit untimed?
The carb fan is one thing- but it had nothing to do with your initial post of pulling off a freeway offramp & engine conking out.
Do you have the EGR system connected?
If so- that's likely the rascal (EGR valve getting stuck open). It creates a huge vacuum leak if it's stuck open & engine won't idle and won't start.
Do you have the EGR system connected?
If so- that's likely the rascal (EGR valve getting stuck open). It creates a huge vacuum leak if it's stuck open & engine won't idle and won't start.
Hook up a vacuum gauge so that you can see it in the cab when driving. The next time it goes into stumble mode and wants to conk out, look at what the vacuum gauge is doing. If vacuum is low, there's a vacuum leak (that for some reason manifests when engine is hot).
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- #27
Thanks for the help @OSS. Went ahead and wires the carb fan to a 10A fused switch rather than dealing with the rest of the circuit. Its at least up and blowing again. One problem temporarily down. Haven't had a chance to check the vacuum as the truck won't idle off of choke right now. I initially had a VCV hooked up to the air intake, intake manifold, and distributor but the local cruiser "expert" told me it was pointless. He advised me to do away with the vcv and hoses as well as the charcoal canister. Suggested that I hook up the fuel tank vent to the air intake port. Im now wondering if this could be the guilty party as it seems to be worse at warm temps. I'll try to get vacuum numbers and try this theory out again in the morning when the temps are better.
Without a switching VCV triggered off the carb, a direct tube from the charcoal canister vent to the intake manifold will create a large vacuum leak.
Either vent the charcoal canister like it was designed at the factory (see the emissions manual) or don't connect it's vent to any engine vacuum.
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- #29
Ok, new thoughts and info after a few things this afternoon. Went out this morning and the truck pulls steady 17mm Hg (I know it should ideally be more) of vacuum but still won't run without choke.
I have previously had issues with the fuel cut solenoid so I am inclined to go that route. The 10A engine fuse is intact with continuity. The ICS has no audible click when going to start the truck. It does click if hot-wired however. I go ahead and Hotwire the ICS and the truck runs without choke. So now I am thinking it's the emissions computer or possibly the ground. I attempt to hardwire a new ground into place with now resolution of my symptoms. At this point I am fairly certain it is the emissions computer causing the issue of not running without choke. Still not sure how that happened from a run down the interstate, but this is currently my working hypothesis. More electrical diagram FSM for those visually inclined.
I have previously had issues with the fuel cut solenoid so I am inclined to go that route. The 10A engine fuse is intact with continuity. The ICS has no audible click when going to start the truck. It does click if hot-wired however. I go ahead and Hotwire the ICS and the truck runs without choke. So now I am thinking it's the emissions computer or possibly the ground. I attempt to hardwire a new ground into place with now resolution of my symptoms. At this point I am fairly certain it is the emissions computer causing the issue of not running without choke. Still not sure how that happened from a run down the interstate, but this is currently my working hypothesis. More electrical diagram FSM for those visually inclined.
NeverGiveUpYota
Dare me.
Electrical diagrams make zero sense to me. I wish I was more help... I’ll look back but you can route vcvs in w/ the cityracer. I have a tee on mine and it ran well (past tense, heads off now, again).
- Thread starter
- #31
Updates:
So between work and prepping for the move I’ve been trying to figure out my continued electrical woes. Went ahead and started by replacing all the fusible links and by my surprise and the cruiser god’s blessing I now have an operational heater. Carb fan is still inoperable in stock form but I’m fine with it working off a toggle switch for now.
My main issue is I still can’t idle. I can start and run poorly with the choke pulled. No clicking from fuel cut solenoid unless I Hotwire directly to the battery.
From my interpretation the fuel cut solenoid is wired as per the photo (my chicken scratch) and pdf provided. If each component is listed correctly, and the connections all have continuity, I’m at a loss for what else could cause the issue. Any thoughts?
So between work and prepping for the move I’ve been trying to figure out my continued electrical woes. Went ahead and started by replacing all the fusible links and by my surprise and the cruiser god’s blessing I now have an operational heater. Carb fan is still inoperable in stock form but I’m fine with it working off a toggle switch for now.
My main issue is I still can’t idle. I can start and run poorly with the choke pulled. No clicking from fuel cut solenoid unless I Hotwire directly to the battery.
From my interpretation the fuel cut solenoid is wired as per the photo (my chicken scratch) and pdf provided. If each component is listed correctly, and the connections all have continuity, I’m at a loss for what else could cause the issue. Any thoughts?
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If the fuel cut solenoid functions with a hot wire (bypassing the emissions computer) but won't activate when hooked up normally, my guess is either the plug at the carb is whacked or the emissions computer's FCS circuit is FUBAR. The only way to rule out the emissions computer is to find another used one and plug it in.
If you can't find one, a McGyver hack could entail rigging up a new standard generic 12V relay powered off the engine fuse circuit to power up (and power off) the FCS when the key is turned. You'd lose the benefits of deceleration fuel cut by bypassing the emissions computer, but that's a small price to pay for a getting a running engine
If you can't find one, a McGyver hack could entail rigging up a new standard generic 12V relay powered off the engine fuse circuit to power up (and power off) the FCS when the key is turned. You'd lose the benefits of deceleration fuel cut by bypassing the emissions computer, but that's a small price to pay for a getting a running engine
NeverGiveUpYota
Dare me.
Pull the block out. Pretty sure it’s anchored in by a few screws.
- Thread starter
- #35
Thanks. I finally figured it out. Wasn’t the culprit but I still can’t figure out why the fcs doesn’t get power when switched on. Tried other solenoids as I happen to have a plethora of carbs currently and they won’t function in place either. Trying to backtrack the wiring so now I’ve got to dive into the PO’s mess of ignition/coil wiring which I’m thinking may be the next issue.
- Thread starter
- #36
Trying to figure out PO and the mess of coil wiring. Anyone have an idea where these plugs actually belong? Trying to undo the PO work and get this as correct as possible. In working left to right I think it's Battery, ?, Tach. Any other ideas?
NeverGiveUpYota
Dare me.
Where is it coming from? The coil? If so, coil has one green plug, tach has green and sometimes if your lucky there’s a third that reduces vibrations or something like that.
- Thread starter
- #38
Well I solved my idle issue. Embarrassed to say that despite my testing the ignition relay for continuity, simply repacking the relay now has the truck back up and idling.
If only things had stopped there. I decided to take it for a drive which is where the problems started. Drove 3mi fine and then I go to get onto the interstate and it starts hesitating and feels like nothing is happening despite me pressing the pedal. Then it starts bucking and I can’t get over 50mph. Take the next exit and it comes to the stoplight idling like a champ. Guessing I’m about to start digging into the carb next.
If only things had stopped there. I decided to take it for a drive which is where the problems started. Drove 3mi fine and then I go to get onto the interstate and it starts hesitating and feels like nothing is happening despite me pressing the pedal. Then it starts bucking and I can’t get over 50mph. Take the next exit and it comes to the stoplight idling like a champ. Guessing I’m about to start digging into the carb next.
- Thread starter
- #39
Been a busy week, but things are now looking up. Had to tow the truck to the shop because of the hesitation under load. Truck was due for suspension work and ended up putting on a new OME medium lift. Took off the carb and the needle valve seat had essentially eaten the associated brass filter. Took off the carb and disassembled it and blew all the junk out. Truck now runs perfectly and rides better than ever with the new lift. Thanks to @CruiserCoLittleRock for all the hard work and help. No way I could’ve gotten this done without y’all in the timeline I had.
no worries Brett, thanks for trusting me with your truck, love finding the solutions to little gremlins like this, its actually rather rewarding as probably everyone on here knows when you figure something out and get it right. good luck in Colorado and let me know if you ever need anything
