Have a rebuilt 302 (by a bronco company called "blank connection") with 400 miles on it. It wont idle. Its a 306 with a "RV" cam, holley truck avenger carb and flat lifters. You can see it on the "blank connection" company web site for build specs. They wont give me any information on the build because I bought the bronco from someone else. They wont even discuss the "standard" crate motor they offer. Go figure. Have had it to 5 shops. Vacuum steady, pertronix III dist and coil sent to factory for testing (ok), fuel pressure good, valve covers removed and rockers etc all good, TDC checked, timing at 10 degrees, firing order older 302: tried 351 order w/o success, holley was swapped out and no change, fuel fresh, plugs new NGK gapped at 35 (had autolites gapped at 45), air fuel ratio 13.9 to 1. Compression 170 on cyn 1 to 6, then 150 on cyn 7 and 8. Shop tells me that the original buyer probably did not break it in properly and rings or cam damaged. They recommend new motor vs removing and repairing mine as more cost effective. Anyone care to offer suggestion on troubleshooting what I havent thought of or comment on replace vs repair?
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Help with new crate 302 that wont idle
- Thread starter twood9mm
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Broncobowsher
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Define won't idle. You state steady vacuum and the ability to set the base timing and it has 400 miles on it, which makes it sound like it is drivable.
As for replacing a 400 mile engine with no known mechanical flaws, sounds like they don't want to do any diagnostic work. The lack of knowing what cam is in it is a huge question. Often crate engines are built and sold on a HP number, often with a huge cam to make that number.
Sounds like you have the basics out of the way. I would be tempted to pull the engine and take it apart. Not so much of a rebuild but an investigation. Look over the parts, get numbers off of them, find out what pistons you have, what cam, etc.
As for replacing a 400 mile engine with no known mechanical flaws, sounds like they don't want to do any diagnostic work. The lack of knowing what cam is in it is a huge question. Often crate engines are built and sold on a HP number, often with a huge cam to make that number.
Sounds like you have the basics out of the way. I would be tempted to pull the engine and take it apart. Not so much of a rebuild but an investigation. Look over the parts, get numbers off of them, find out what pistons you have, what cam, etc.
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Hey twood, welcome to classicbroncos! Sorry it's for such a crappy reason, but hopefully you can find help (or just solace) here.
And since I don't have an answer for you at the moment (still thinking), I'll just throw in an FYI that a rebuilt engine is not a "crate motor" just so we're on the same page.
Crate motor is all brand new stuff, including the block. A rebuilt engine is simply a rebuilt engine.
Ok, so that out of the way....%);D Did the company doing the diagnostics at least test for sure if the cam lobes were flat? Did they remove the valve covers and run it for a bit?
They're correct that this could be a cam issue of course. Not knowing if the new cam was properly broken in is a huge question mark with any new setup. But it's easy to test too, while the engine is running I would think. Messy, but doable.
Checking to see if all valves are being opened the same amount, even just visually, can go a long way to deciding which direction to take.
Even rocker arms get loose and pushrods bend and fall out.
But then, there's that steady vacuum thing you mentioned (good full explanation/description by the way!) which would normally indicate zero issues with the valvetrain.
But while that's not helping, it may still be very good news!
What is the vacuum reading by the way? Less than 15? Or is it between 17 and 21? The latter being fantastic vacuum for a cammed engine. Especially when it's an unknown generic "RV" cam and not a known part.
Crappy of the builder to keep information secret though. Once it's sold anyone can easily check there products and build quality. Wonder why they think nobody but the original purchaser has the need, or the right to know details.
Strange.
I'm with Broncobowsher too, in saying hold off on all the new-motor talk until more things have been determined for sure. An engine can survive a wiped out cam and it would be a shame to waste all that nice new stuff.
The engine might not be happy by any stretch, but it can still survive and come back to play hard again.
When you were verifying the firing order, did you watch rocker arms, or at least put a finger over the different spark plug holes to verify the order 100%? This may be important, so keep that in mind if you did not.
And what about the carburetor? Will it idle (even too high) at some point if you just keep turning the adjusting screw farther and farther? At what point does it run without you pushing on the throttle?
Did you check for vacuum leaks while it's running? And what about the PCV valve? Is it connected correctly?
Ignition timing, pcv valve, evaporative emissions stuff connected (if applicable)? Anything else modified you know of?
Got any pics of the engine compartment you can post up for us to see? Aside from the act that we love to see pics of all our Broncos here, we might also be able to see something amiss that others might have missed.
Not sure how familiar you are with Early Broncos in general, but not so much a pic might help. As it often does.
Good luck! Oh, and what year is your Bronco? Not sure if I asked that already.
Paul
And since I don't have an answer for you at the moment (still thinking), I'll just throw in an FYI that a rebuilt engine is not a "crate motor" just so we're on the same page.
Crate motor is all brand new stuff, including the block. A rebuilt engine is simply a rebuilt engine.
Ok, so that out of the way....%);D Did the company doing the diagnostics at least test for sure if the cam lobes were flat? Did they remove the valve covers and run it for a bit?
They're correct that this could be a cam issue of course. Not knowing if the new cam was properly broken in is a huge question mark with any new setup. But it's easy to test too, while the engine is running I would think. Messy, but doable.
Checking to see if all valves are being opened the same amount, even just visually, can go a long way to deciding which direction to take.
Even rocker arms get loose and pushrods bend and fall out.
But then, there's that steady vacuum thing you mentioned (good full explanation/description by the way!) which would normally indicate zero issues with the valvetrain.
But while that's not helping, it may still be very good news!
What is the vacuum reading by the way? Less than 15? Or is it between 17 and 21? The latter being fantastic vacuum for a cammed engine. Especially when it's an unknown generic "RV" cam and not a known part.
Crappy of the builder to keep information secret though. Once it's sold anyone can easily check there products and build quality. Wonder why they think nobody but the original purchaser has the need, or the right to know details.
Strange.
I'm with Broncobowsher too, in saying hold off on all the new-motor talk until more things have been determined for sure. An engine can survive a wiped out cam and it would be a shame to waste all that nice new stuff.
The engine might not be happy by any stretch, but it can still survive and come back to play hard again.
When you were verifying the firing order, did you watch rocker arms, or at least put a finger over the different spark plug holes to verify the order 100%? This may be important, so keep that in mind if you did not.
And what about the carburetor? Will it idle (even too high) at some point if you just keep turning the adjusting screw farther and farther? At what point does it run without you pushing on the throttle?
Did you check for vacuum leaks while it's running? And what about the PCV valve? Is it connected correctly?
Ignition timing, pcv valve, evaporative emissions stuff connected (if applicable)? Anything else modified you know of?
Got any pics of the engine compartment you can post up for us to see? Aside from the act that we love to see pics of all our Broncos here, we might also be able to see something amiss that others might have missed.
Not sure how familiar you are with Early Broncos in general, but not so much a pic might help. As it often does.
Good luck! Oh, and what year is your Bronco? Not sure if I asked that already.
Paul
Hi, been thinking about the idle and I keep coming up with a couple of things. Besides young guys mostly don't know or want to know about carbs, I would triple check the basic stuff. First, check and make sure the high idle cam on the choke side is completely off. Next remove and plug any vacuum hoses from the carb and intake manifold to eliminate these as a source of a vacuum leak. Next remove the carb and all the gaskets and spacers and make sure they are all right side up and lined up properly. Make sure the holes in the gaskets are not hanging up the throttle plates. There should be no sealer used. I've re- used carb gaskets before that should not be a problem, unless a gasket or spacer is ruined or cracked. Just snug down the carb nuts, medium snug. No muscle power. If you take the carb off you can verify the throttle plates are completely closed, and in the transfer slot area in the venturis. Good luck
Broncobowsher
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I'm still waiting for what "won't idle" means to the original poster.
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What does won't idle mean? Stalls? Rough? What is the vacuum?
My dad sold his 1968 GTO because it was too "loud". I keep reminding him of that error..
How does it run off idle? 400 miles it moves then? How, scalded ape fast, barely, middle of road fast?
What is the name of the engine shop? Not finding a blank connection in google, do you have a link?
My dad sold his 1968 GTO because it was too "loud". I keep reminding him of that error..
How does it run off idle? 400 miles it moves then? How, scalded ape fast, barely, middle of road fast?
What is the name of the engine shop? Not finding a blank connection in google, do you have a link?
Rustytruck
Bronco Guru
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So your off on a bad foot. Someone sells you a used Bronco that the engine is running poorly and you start out bad mouthing the company you have no personal dealings with. Then you post that 5 shops can't fix or find what the actual problem is. Slaming the first company isn't fair. You bought a problem its your problem not theirs. Take it up with the seller.
With such low miles pull the engine out and do a full tear down of the engine. Suspect everything. Unless the bores are scored parts to repair should not be too expensive. 7/8 are a problem, focus on there, starting at the pistons and work your way up from there. 2 or 3 days labor if you use someone that knows what they are doing. My guess a grand should do it. Then you have to take it some place to be properly tuned with someone who knows what the hell they are doing.
With such low miles pull the engine out and do a full tear down of the engine. Suspect everything. Unless the bores are scored parts to repair should not be too expensive. 7/8 are a problem, focus on there, starting at the pistons and work your way up from there. 2 or 3 days labor if you use someone that knows what they are doing. My guess a grand should do it. Then you have to take it some place to be properly tuned with someone who knows what the hell they are doing.
Help with new crate 302 that wont idle, cont.
Thank you all for the great comments. I greatly appreciate it. Yes, I know I missed used the phrase "crate" engine. Its really a rebuilt turnkey. Although, I didn't think the one comment about me bashing the vender was professional. I certainly didn't blame the builder (vender) or the seller as I don't even have enough information to do that. Please reread the original post.
Since I suspected a cam issue, I needed to know what cam I had in order to proceed. I sent 3 emails and made numerous phone calls to the vender that went unanswered. I did get through twice on the phone and was connected to the "engine builder". He couldn't answer what "RV" cam they put into their base engine (the one I have) as advertised on their web site. I left a message requesting to speak to the owner but they have yet to respond. Certainly not bashing.
There where a lot of questions regarding my "wont idle" issue so Ill try to clarify. When in gear (C4), engine idles for about 10 seconds then stumbles as if the fuel was cut off and nearly dies. This cycles over and over while in gear. It forces you to put it into neutral at stops. Idle when in neutral is 1000 rpm because it drops about 350 rpm in gear and then cycles. Runs ok at speed. Vacuum is 20 and rock steady. Shop sprayed all around the intake etc looking for leaks but none found. Carb and gasket was replaced with no change. Valve covers removed while engine running (messy for sure) but nothing noticeable wrong. Did not put dial on to check cam lobes (yet). Vacuum lines plugged and no change. Recall I sent the pertronix III to the factory and it checked ok.
I confess I am not an engine mechanic and must rely on others. All we have found so far is the lower compression in cyn 7 and 8 however, I don't think that would cause this. It appears the cam must be at fault ?
Again, thanks to all for your replies.
Thank you all for the great comments. I greatly appreciate it. Yes, I know I missed used the phrase "crate" engine. Its really a rebuilt turnkey. Although, I didn't think the one comment about me bashing the vender was professional. I certainly didn't blame the builder (vender) or the seller as I don't even have enough information to do that. Please reread the original post.
Since I suspected a cam issue, I needed to know what cam I had in order to proceed. I sent 3 emails and made numerous phone calls to the vender that went unanswered. I did get through twice on the phone and was connected to the "engine builder". He couldn't answer what "RV" cam they put into their base engine (the one I have) as advertised on their web site. I left a message requesting to speak to the owner but they have yet to respond. Certainly not bashing.
There where a lot of questions regarding my "wont idle" issue so Ill try to clarify. When in gear (C4), engine idles for about 10 seconds then stumbles as if the fuel was cut off and nearly dies. This cycles over and over while in gear. It forces you to put it into neutral at stops. Idle when in neutral is 1000 rpm because it drops about 350 rpm in gear and then cycles. Runs ok at speed. Vacuum is 20 and rock steady. Shop sprayed all around the intake etc looking for leaks but none found. Carb and gasket was replaced with no change. Valve covers removed while engine running (messy for sure) but nothing noticeable wrong. Did not put dial on to check cam lobes (yet). Vacuum lines plugged and no change. Recall I sent the pertronix III to the factory and it checked ok.
I confess I am not an engine mechanic and must rely on others. All we have found so far is the lower compression in cyn 7 and 8 however, I don't think that would cause this. It appears the cam must be at fault ?
Again, thanks to all for your replies.
broncodriver99
Bronco Guru
LOL. Free advice is rarely "Professional". Rusty did offer good advice though. Some sort of inspection is going to be necessary if you want to know exactly what you have. Unless, of course you just have had 5 bad mechanics, which is quite possible these days.
That said, I am having a hard time understanding why they won't give you any information on the build, it is yours now. Although it sounds like maybe you only talked to the one guy.
Have they checked that your rockers are properly adjusted?
It does sound like it is time to pull at least the heads. You will be able to check the cylinders and heads for the cost of a set of gaskets. You can also pull the water pump, timing cover, and timing chain gear and see if there is any info printed on the cam.
Rustytruck
Bronco Guru
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If you have a motor with EGR the EGR valve hanging up at idle will act like this. Since we know nothing about the engine and no pictures to see what your working with it leaves us guessing, just like the issue your having finding out just what parts are in your motor.
Might try when the engine is acting up at idle find a safe place to park and open hood and run the engine stopped in gear and see with the open hood and more airflow in the engine compartment if the engine cools off better and the idle problems go away indication a vapor /fuel pressure issue. Its been really hot out here lately.
Cam issues work all the time and not in specific situations unless you have a modern motor with variable valve timing. If at times it idles good the cam is doing its job if it suddenly changes its idle the cam didn't change, its still doing its part so what changed? A sticky lifter or valve maybe? If it changes and stays then suspecting a hard part issue is more valid path.
If you connect a vacuum gauge on manifold vacuum and the gauge is rock steady the engine is pretty solid mechanically. If the vacuum is low it can be a timing issue. If the gauge is not steady but has a beat to it it has a cylinder issue, a miss fire, a stuck valve a singular cylinder issue. A constant twitching needle issue with a lower than normal reading is usually a fuel mixture issue. There is allot of help on line as to what vacuum gauge readings mean and a worthy time investment. I hope you resolve the problems your having soon.
Might try when the engine is acting up at idle find a safe place to park and open hood and run the engine stopped in gear and see with the open hood and more airflow in the engine compartment if the engine cools off better and the idle problems go away indication a vapor /fuel pressure issue. Its been really hot out here lately.
Cam issues work all the time and not in specific situations unless you have a modern motor with variable valve timing. If at times it idles good the cam is doing its job if it suddenly changes its idle the cam didn't change, its still doing its part so what changed? A sticky lifter or valve maybe? If it changes and stays then suspecting a hard part issue is more valid path.
If you connect a vacuum gauge on manifold vacuum and the gauge is rock steady the engine is pretty solid mechanically. If the vacuum is low it can be a timing issue. If the gauge is not steady but has a beat to it it has a cylinder issue, a miss fire, a stuck valve a singular cylinder issue. A constant twitching needle issue with a lower than normal reading is usually a fuel mixture issue. There is allot of help on line as to what vacuum gauge readings mean and a worthy time investment. I hope you resolve the problems your having soon.
We disconnected that line with no change Good suggestion.
I have to learn how to post pictures. Only has pcv valve, no egr. early block late model heads (but not a roller cam). Vacuum gauge is steady. No movement at all. Thanks
You are correct that its free advise. Not trying to beat up on anyone. I'm just lost on this issue. Only did a visual on the rockers without seeing anything that appeared wrong (shop did but I was there). You have a good recommendation. Ill explore it. and thank you
Thanks. Really wasn't trying to bad mouth the vender but they are just being very unhelpful. HAving the build specs would help me a lot. That said, I will keep your recommendation in mind vs "new" rebuilt motor". Appreciate it.
Sorry, just getting used to this forum. I have clarified it further on but here it is again: idles in neutral ok. In gear, it idles for 10 seconds then chocks and almost dies. This cycles on and off when in gear. idle is set at about 1100 in neutral to try to get it to stay lit in gear.
Rustytruck
Bronco Guru
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Is the motor sealed with a rebuild tag? Allot of professional re-builders will adhere tags for warranty verification. When I bought my motors from ATK engines they had such a tag and could trace its build.
I didn't know that but haven't seen one I will look for it. Any ideas where it could be placed? By the way, would you recommend ATK? I have been looking at them just in case.
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