stupidnoob

For starters... I have read thread after thread after thread about rough idles, and I am very aware that the poppet valve design of the CPFI being poor.

The Scoop:

I replaced the engine in my parents van (5.7l). I got it running after a couple disasters, including but not limited too having to pull the front cover to install the reluctor wheel I didnt realize was back there during assembly, and HOURS fighting the valve adjustment with little luck in that department.

I have had a problem where it misfires lightly when cold (hard to start some times, furthermore sometimes it then takes a second to sputter to life). When warm the misfire increases in cylinders 5 and 6 upwards of 100 hits in a counting cycle in each.

I have also found it doesnt get to opperating temperature (or at least according to the sender) I put another thermostat in it and its the same story, only hits 156 degrees and of course using a co-workers Genisys it has to hit 158 to allow the crankshaft relearn process so I have been unable to do that yet.

My Logic:

Considering they are really only 5 and 6 misfiring being opposite sides of the motor, I would lean away from a vacuum leak (intake manifold gaskets). Because 5-6 are in the center of the motor I would assume an intake manifold seal problem in the same spot on both banks would at LEAST affect the other center cylinders 3-4 and they dont count a single misfire. My adaptives are maxed 25+ so I am missing for sure, really only at idle too... I really dont see any misfires count while I am driving, but rolling up to a stop sign the whole van starts shaking as the motor is bucking it its mounts. I dont feel like I am really down power either (hard to tell of course, i didnt really ever drive this van) but it pulls as good as I would expect a 350 gas engine would pull a 15pass 3500 express van.

Using the search I found a simiar issue resolved with cranshaft position sensor shims, of which I purchased due to witness marks on the CKP sensor, with no luck.

I got some Top Engine Cleaner from some ex-cadillac techs I work with and ran that through capping off the feed and return and bumping the pressure up to 100ish psi with no luck. Naturally I am leaning towards the CPFI spider, but an E-bay setup is going to be 300.00 dollars, combine with some gaskets I need due to oil leaks created when I pulled the timing cover the first time, its going to be upwards of 550-600 dollars to do everything and I just want a little more insite before I commit only to spend the HOURS replacing parts and money for the parts only to start it up and still have it running like crap.

What Has Been Done:

Part of my money concern is my parents are already into this about 3800 dollars for:
-fresh reman motor
-belts
-hoses
-exhaust manifolds
-tensioner
-idler
-radiator for the oil cooler
-oil cooler lines
-water pump
-front cover
-balancer
-all new hardwhere where it matters
-labor to me (which I have spent A LOT of time free to them on this stupid thing). I usually do 50 dollars an hour for side jobs, for what they paid me I got paid for 12 hours, which is fine I want to help them and keep the cost down.
-almost everything was replaced, except the intake manifold and up from there. The intake manifold spent multiple hours in the parts washer at work, with scrubbings mixed in. Basically everything I took off that was questionable was replaced.


My Plans:

Before I go ahead and tell them they need this stuff, I would like to verify my grounds, hopefully alldata can give me a connector pinout for the VCM connectors and Ill ohm out all the grounds.

From there I am to the point where I feel updating the CPFI system to the MFI system is going to be the next step. At that time the oil pan, front cover and lower intake manifold will come off and get new gaskets and seals to stop this stupid oil leak and absolutely verify a good seal.

If it sounds like I am on track, great, I am just at my whits end on this stupid van I probably have 50+ hours into putting the motor in, repulling the front cover, redoing the oil pan gasket, attempting to adjust the valves over and over and OVER AND OVER, cleaning the injectors, putting a new-new thermostat in... and the aforementioned direction I feel like taking will be another 10+/- hours in my driveway with my crappy set of home tools. I just want it to be done!!!

Thank you for ANY input, If any more information would help you in your guess just ask, I probably have it but didnt put it in the post to keep this short and sweet (= FAIL)...

-Andrew Long

stupidnoob

anybody, Bueler, Bueler?

I am going to give this one bump, then gracefully let it die... bump!?