Dave, any news on the idling/missing/hesitation issues? Hope all is well!
Hey man.. no news yet. My coolant temp sensor should be in my mailbox today and I'll probably install that this weekend to see if it's as simple as a bad sensor.
If it continues after that.. I will start looking into the things Larry just rocked my knowledge world with. hah.
WOW! That turned out great Dave! Looks awesome :drool:
By the looks of your work, you are not a rookie with a wrench so my .02 cents are probably things already on your to do list. Anyway, a few thoughts…… it sounds like the erratic idle and hesitation only occur before the engine comes up to operating temperature? If that is the case I would suspect a vacuum leak somewhere near the throttle body and intake. It is not uncommon for a vacuum leak to be present only when all the metal and aluminum things are cold. Once they heat up and expand the vacuum leak source can seal and symptoms go away. Spray some carb cleaner around the throttle body and intake when cold and see if you notice any changes in RPM. With the issues you had with the EGR valve port machining would be another great spot to inspect closely with some carb cleaner as well.
As you are most likely aware, when the engine is started cold the ECM operates in Open Loop status and ignores the O2 and loosely calculates the air fuel ratio based on inputs from only the coolant temp sensor and MAP. Much of the engine operation calibrations in Open Loop are predetermined by ECM PROM programming. Once the engine comes up to temperature, starts reading the O2 and goes into Closed Loop the ECM takes inputs from all sensors more seriously to make adjustments to the air/fuel mixtures, ignition timing, etc. With that, it is possible there is nothing actually wrong with the engine but something out of whack with Edelbrock’s ECM prom tuning (I saw an earlier post where Edelbrock did the prom tuning). Who knows, they may have the engine going into Closed Loop too soon or something along those lines. But before reaching out to Edelbrock check for vacuum leaks as mentioned above as well as verify the MAP sensor is receiving the proper manifold vacuum signal. I played hell with a TBI 7.4L swap not long ago and made a total rookie mistake by plumbing the MAP to ported vacuum but I played bigger hell pulling my hair out trying to find the root cause of a rolling stop dying problem. Come to find out, there was nothing wrong with anything on the engine it was the prom tuners mistake by calibrating it to an automatic instead of a manual trans plus they had it programmed to always run in Closed Loop, even ice cool! My point is, once ECM work has been done don’t always assume the tuners don’t make mistakes too. When doing major engine work and ECM tuning at the same time makes it hard to separate the straw from the manure chasing drivability issues afterwards to figure out what is tuning related and what is not. If you have access to a scan tool to monitor what the sensors are doing would make diagnosing this much easier and verify if the issue is only present during open vs. close loop and determine if there is a real issue with the engine or just a ECM tuning issue.
Say, how do you like that K&N air intake? I used that same one on a TBI 4.3L V6 to TBI 7.4L swap recently and the air horn that mounts to the throttle body doesn’t seem to fit very well as it seems to move those three studs around and keeps squeezing out the foam seal between the air horn and TB. K&N was nice enough to send me a couple extra foam seals but I am still not happy the way the air horn seals. To me it seems like the 3 holes in the air horn are not drilled in the right spots.
The little ½ ton short bed Sportside runs like a scaled dog with a big block though.
Your work looks great! Keep us posted
Wow, Larry! Thank you so much for all of that information and for the kudos. It's like Picasso just told me I can paint pretty well. haha!
I had a lot of help with the motor swap.. this was my first one. My father in law though (owner of the shop and the major tools I used to complete this job) has done a couple motor swaps in his day, so he was guiding me and helping me along the way. Was a great experience though and I feel like it was a great success as well!
Thanks.
As for the vacuum leak.. that sounds like a complete possibility. So with the carb cleaner trick, do you mean to just spray a mist of cleaner into the air around the TBI as it runs and the idea is if there IS a leak, it'll suck it in and change the RPM? Just making sure I understand the process before I try it.
Thank you.
The Edelbrock tuned piggy-back chip is something in my mind as well. It will definitely be lower on the list though (as you said too) as I want to make sure the rest of the possibilities are corrected and be sure I've narrowed it down that all the things we did are solid. If it still continues at that point, I will call the contacts over at Edelbrock and explain the situation I have. The great thing about living in the same city as them is I can probably just drive the thing over there and talk to them direct and see what they can do for me..
As for the K&N, yeah, I've noticed the same thing. That little gasket foam piece tore already on this one and I had to glue/gasket seal the thing back together. How did you get them to send you a few more? I need to do that as well. I notice that if you pull the intake off a couple times, that foam is basically shot, making the next time you re-install it that much harder to get it to seat right.
Aside from the foam piece though, I really like the intake itself. Mine seems to bolt up pretty well on here. The only issue I have is that I need to get a longer breather tube from the back of the horn because I actually have one of those air spacers in between my TBI and manifold and it raised it up a couple inches and now the tube they gave BARELY reaches my stem in the valve cover. Outside of that though, fantastic system and I still recommend it to others over any other ones I have seen that don't look like they work as well.
