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Okay so I posted recently saying I couldn’t get my new to me 351 to start. I changed my harness over and now she starts and runs good, makes good power, idles high but that is because of vaccum leak. That will be resolved today.
So the issue is, I have a hard/slow crank when hot condition. I’m almost certain it is timing but I am very green when it comes to timing. Always been intimidated by it. I do not have any timing tools and was hoping I would not need any, but I can probably acces them through a fried or friends friend if need be. Can someone explain where to start on checking my timing, and put it in layman’s terms? I know there’s a timing pointer and timing marks on the flywheel, and the distributor can be turned to achieve what is needed but I don’t know how to turn it what direction etc.. my timing can’t be terribly out because the truck runs great very responsive and stout.
First thing is to make sure that timing (too much advance) is causing your hot-start problem. In order to do this, when the engine is hot and you are experiencing this issue, pull the coil wire off the distributor and ground it. If you can then crank over as normal (ie, not slow), then timing is the problem. If the engine still cranks slowly with the coil wire grounded, it is most likely a bad starter.
First thing is to make sure that timing (too much advance) is causing your hot-start problem. In order to do this, when the engine is hot and you are experiencing this issue, pull the coil wire off the distributor and ground it. If you can then crank over as normal (ie, not slow), then timing is the problem. If the engine still cranks slowly with the coil wire grounded, it is most likely a bad starter.
thanks I never thought of that I will try that when I get home. My starter worked good with the previous motor but it could possibly be that my new motor has a little more compression and me having headers doesn’t help anything because Of the heat soak. Also the new motor runs rather hot. On the upper most side of “normal” on the dash temp gauge. This could also result from the timing correct?
A timing light is one of the top 3 investments for our trucks, prolly any vehicle, Hopefully pics are big enuff to see marks, first clean off distributor base and hold down clamp, you should have an mark(indention) on distributor base and block where they meet each other, first pic, second pic is hold down bolt and clamp removed to see marks better, if the timing hasn't been moved the marks should line up, hope this dont confuse you - if the mark(indention) on distributor is to the left side of mark(indention) on block, the timing has been advanced, maybe too far, and your getting hard start(dragging the starter sound) us old folks call it, before you move distributor, use Sharpie and make new line-up marks if you dont have the marks(indentions), so when you twist(turn) distributor, left(clockwise) advance timing or right(counter-clockwise) retard timing, you can go back to the new marks, if the direction you went didn't help (e.g. made worse, better, no change)
clean this area marks should line up if at base timing 10*, bolt hold down removed to see better
I know there’s a timing pointer and timing marks on the flywheel, and the distributor can be turned to achieve what is needed but I don’t know how to turn it what direction etc.. my timing can’t be terribly out because the truck runs great very responsive and stout.
The timing marks are on the balancer. The flywheel is on the back of the engine but only if you have a manual transmission otherwise it is a flexplate.
I honestly never thought about which way to turn the distributor. If the mark is getting further from the pointer I turned it the wrong way. Don’t be intimidated by the process. Follow the directions in rla’s post and you’ll be fine.
The timing marks are on the balancer. The flywheel is on the back of the engine but only if you have a manual transmission otherwise it is a flexplate.
I honestly never thought about which way to turn the distributor. If the mark is getting further from the pointer I turned it the wrong way. Don’t be intimidated by the process. Follow the directions in rla’s post and you’ll be fine.
right I knew balancer, guess I just had a moment. Early in the morning when I typed that and still half asleep lol. Tons of great advice and help on here. The pictures posted by rla are very helpful. This forum is awesome. I will be home shortly to let the truck warm up and pull the dizzy to coil wire. Il be back
Be sure to follow the link above about setting timing on an EFI system, you have to remove the spout plug to disable computer advance or you will end up with the timing retarded more than it should be.
Okay guys I got home and warmed the truck up and turned it off. Tried to restart and got hard crank, unhooked main dizzy wire and it cranked fine. I am also getting a high idle and a miss and the truck stalls easy when I try to drive it but runs like a raped ape when it is WOT. My temps also go down at WOT to what I would call normal or acceptable. Now that I ran the truck in the day light I see I am getting some black smoke. Quite a bit actually. The person I bought the engine off of sent me a video of it running and there was a considerable amount of black smoke in the video but he said it was soot out of a muffler he had to stick on it. So that tells me it is something to do with the engine and it’s components that I bought since I am having the same issue. Could this be because of the timing as well? To add, The PO had installed new seals and gaskets on the engine so maybe when they stabbed the dizzy they got it wrong. Sorry for the long post. I’d rather it be long than be a double post.
di it have a 351 in it and swapped 351 for 351, why new harness? maybe thats issue? did you change pcm out also? maybe you should list what you have, or he done to motor, just way to many variables, or something added to the equation,each time you post news, the list could be endless to whats causing it, pull codes? stock injectors? O2(oxygen) sensor good/bad/gone? fuel pressure reading? vacuum reading at idle? get timing light yet? cant guess or assume its right? They will bend over backwards to help if you give all info first, instead of tidbits on each post.
di it have a 351 in it and swapped 351 for 351, why new harness? maybe thats issue? did you change pcm out also? maybe you should list what you have, or he done to motor, just way to many variables, or something added to the equation,each time you post news, the list could be endless to whats causing it, pull codes? stock injectors? O2(oxygen) sensor good/bad/gone? fuel pressure reading? vacuum reading at idle? get timing light yet? cant guess or assume its right? They will bend over backwards to help if you give all info first, instead of tidbits on each post.
yes I swapped 351 for 351. Had to switch harness because engine was a 93 and my truck is a 96 conaski got me headed the right direction on that. No I did not change the pcm. I do not have any spares other than for an idi and I can not afford to buy one just to throw parts at it. New gaskets and seals is all that has been done to the motor to my knowledge. I just acquired it. My truck has never shown a CEL and it should be on right now. I assume the injectors are stock. I do not have any testing equipment right now. My truck is no gem piece but it’s all I have at the moment. And I know the last motor ran great aside from starting to knock so I can only assume that the new engine is where my problem lies. I.e. timing. I am only posting as much as I know for the time being and trying to learn. Not to be a dick but seems like you might be headed that direction. Hard to tell over the internet how someone is coming off though. Hope to not have offended you with my limited resources and knowledge on certain things. Can’t learn if you don’t ask.
Generally black smoke is too much fuel. Which harness is in the truck? Is the fuel pressure regulator leaking as in is there fuel coming out of the vacuum port if you remove the hose? It could be an injector problem but you need to do some testing of components before replacing parts. That gets expensive very fast.
The only way to figure it out yourself will be to get some tools or rent them if available.
Generally black smoke is too much fuel. Which harness is in the truck? Is the fuel pressure regulator leaking as in is there fuel coming out of the vacuum port if you remove the hose? It could be an injector problem but you need to do some testing of components before replacing parts. That gets expensive very fast.
The only way to figure it out yourself will be to get some tools or rent them if available.
I am not sure which harness as in part number, but it was original to my 96 model truck as far as I know. There is no fuel leaking from the pressure regulator but I will check the vaccum line for any cracks today. The tools needed is my next step. Once I acquire the tools I will post back if I have any more questions or have resolved the problem. Thanks guys. Lots of wisdom here 👍🏼
