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Topic Review (Newest First)
03-12-2013 08:03 PM
skippy89 Jaw22w: The factory setting for these engines is 0 degrees, not sure why, it's probably just the distributor and computer set up.

But I have great news, regarding my idle, as of the last hour of working on the truck. I hooked up my laptop to the ECU, and used my Tuner Pro Rt software. I ran it for awhile watching the engine run through the computer, and realized that my TPS sensor didn't look quite right. Normal factory TBI units, TPS sensor should sit at 0.50 volts, my setup is required to run at 0.65 volts at idle. The computer showed my new, BWD TPS sitting at 1.45 volts. Essentially making my computer think I'm sitting there with my foot on the gas, while not getting the proper air flow required, for the amount of gas, I was getting. So I replaced the BWD TPS, with my old fully adjustable TPS, and set it up at 0.65 volts. Idle ran a steady 650 RPM, for 20 minutes. I also checked my fuel pressure before my filter, and it's sitting steady at 11 PSI, and when I turn off the engine the PSI drops down to 8 PSI and holds it. I still need to wait until the morning to see how it does cold, but I think, I can finally say, case closed with the dramatic idle issue. As for the slight rise in temperature, about an 1/8 inch past 210 degrees, I haven't got that figured out yet. I might flush the radiator, since some of you, are suggesting it might be blockage.
03-09-2013 07:27 PM
jaw22w Post #11---And timing, originally, I set it by unplugging a wire and setting it at 0. I remember at one point i went to check my timing after all this happened. I unplugged the wire, and the truck wouldn't start. Then i started it, and unplugged it and it went into a violent fit until it finally died, even after i plugged the wire back in after it was running. I haven't tried messing with that since that episode, because it ran fine was i cleared the computer.

Are you talking about setting the ignition timing? If so, your timing could be way off. 0 degrees is not enough advance. A retarded engine can run hot and do all sorts of crazy things. Please explain your timing method.
03-09-2013 06:40 PM
skippy89 Alrighty guys, I have the vacuum results in. At start up I read 18 lbs with rapid shaking, then it started to fluctuate between 16 and 18 lbs for a few minutes before deciding to drop to 14 lbs and fluctuate at a steady rate between 14 and 16. That reading isn't at my worst idle, I still had the fluctuating idle, but it was no where near as nasty as it gets in the mornings. My vacuum results pointed to late ignition timing, which confuses me because my timing was dead on, before I started having these problems.
03-05-2013 06:51 PM
cliff tate
loss of coolant

has the rad bin cleaned,sounds like restriction in the rad which causes cavitation,flow restriction causes the water pump to cavitate,airiating water
03-05-2013 05:42 PM
skippy89 Alright guys sorry I haven't been on in a while, I decided to take a break from this headache. My cooling issues haven't been as bad as they were, but the temperture is still going over the normal 210 heat range that it was always ran at strong. I picked up a tee and some vacuum line from NAPA today, so I can check the vacuum pressure. And my Actron fuel pressure fitting and tester came in the mail the other day, so I can see how the pump is doing, I want to say its the original pump but idk. The surging idle issue is getting much worse now, almost to the point of stalling. And its now starting to surge while stopped in gear. I've also noticed that on a cold start, the engine misses roughly five times and then the idle smoothes out, until it goes into the surging fit. My thermostat housing is also start to seap coolant and chunks of what seems to be gasket material.....I guess I'll take that off again and see what's up.
02-21-2013 12:42 PM
Head Gasket Leak?

When hot pull your dip stick out and put it on your hot header and if the oil just runs off, your allright but if you hear a silzer noise its blown head gasket? Old way of check but now you can take it to auto Zone and they will check it with a raydeater cap vacme gage.
Doug Ray
02-21-2013 09:09 AM
Northern Chevy I won't claim to say this is the best location to hook up a vacuum gauge but definitely gives a proper reading at idle assuming the EGR being disconnected causing a problem. The other way is to have a T connector so you can keep the EGR line hooked up. The fitting is at the front of the TBI right next to the large PCV line.

Up here they suggest a 195 thermostat but a slightly cooler one might be better for your location but with whatever you decide on, T stats don't cost a lot and I'd say its easier to just put in another one while your doing through the motions of draining coolant out anyway.

You had a new fan clutch mounted up for your drive in this morning ?
02-21-2013 07:55 AM
skippy89 Well, I drove to work this morning and it started to get a little warmer than what I would like, so I'll tear into the thermostat again and make sure I don't have any rtv on it, causing any blockage. Then its back to the drawing bored again if that's not the problem....

It just didn't have any resistance, once it was warmed up, I turned it off and the fan just continued to spin freely.

I'll check the vaccum when I di the t-stat, where do you suggest I hook up the vacuum gauge? I have one available vacuum port on the far right of the tbi.
02-20-2013 08:50 PM
Northern Chevy How did he determine the fan clutch was bad or should say the viscous clutch as it only locks up when the engine would be quite hot and if everything is working properly and since its winter, the clutch would never have reason to kick in. I am guessing he meant the viscous assembly was weak as they will fail or leak out and then just about free wheel from what I have been told. I've found with those clutches or at least for my 95 chevy, the factory one never did lock up so I thought it was a dud and bought an aftermarket one and it took a lot of temperature for it to lock up { covering the grill in the summer time to experiment with this } . I don't like to see the temperature start climbing much over that 100c / 212f mark as I know the thermostat is probably all the way open by then and the temps can just sky rocket without warning after that. I'm not saying you should do this to your brand new clutch but just for future reference if you ever needed to do this. I re bent the outer tip of the bi metal spring a little to get the clutch cutting in earlier although not at too low a temperature as that would be very bad for over cooling and use a lot of gas to drive it. It worked well though when I did that modification and installed the largest rad I could find to fit the truck before heading through Death Valley in the middle of summer although I still kept the conditioning off... and its a black truck !.

I would suspect a leaking fuel injector isn't going to help the way the engine idles and probably should get that repaired or replaced before chasing everything else down for the surging idle situation.
02-20-2013 08:16 PM
64nailhead Take note of the editor of that wiki article, Cobalt, you can thank him. Also there is a ton of great info there. It's worth checking out whenever you have questions about something your working on that you're not sure of.

I'm really glad to here that you found the problem. Remember, always start with basics so as to eliminate the little things first.
02-20-2013 05:46 PM
skippy89 yeah i didn't care much for my method with the silicone, i hate the way it looks. I'll try your method next time

I'm working on getting a new distributor also, my old one was out of my truck for about a month and i went to put it on and realized it was seized up. So i took it apart and cleaned it up, and cross hatched the shaft to help hold the oil i put on it. soon enough i'll have a complete 6 AL MSD ignition system set up.

So i stopped by the radiator shop today to have them check it out and see what they thought, and something i completely overlooked. My fan clutch is bad, that's why i was over heating on my way to work at the slow speeds. And apparently the bubbles are normal because my return line for my heater core enters right at the cap. And that causes bubbles to escape at the mouth of the radiator. I'll replace the clutch today and see what happens thanks guys Now just to figure out the surging idle, I'll do a vacuum check as soon as possible and get the information to you. That chart for vacuum looks like it will be very helpful 64nailhead, i didn't realize you could tell so much about vacuum
02-20-2013 07:53 AM
Northern Chevy Unfortunately due to dial up I only saw the first few seconds of the coolant beginning to flow out of the rad but was reading over 64nailheads thoughts and nodding my head repeatedly. The water pump, general tune up parts and so forth should all be new with a new engine installation as it would be like buying a new truck off the lot and it had a number of half worn out parts put on it, take a guess how well that would work out down the road a ways in miles and years. Its bad enough with the accessories that tend to get swapped over such as a well worn starter, alternator, TBI assembly { which you are having problems with } as by rights all those items should be new as well, distributor and on and on. Unfortunately an engine install that covers all those externals as new is FAR more expensive then the initial cost of the basic long block drop in. It might sound like I am coming down on on you hard but that isn't the intention of my comments in the least, its just pointing out that doing a new engine install and covering all basis isn't inexpensive.

Hi tack, that product is wonderful for those times it fits the situation as it leaves a nice THIN layer of sealant on the surface and will add, its very advisable to wear those throw away thin gloves when working with it. While I use RTV or other types of silicone, the diff cover for example and so forth that doesn't use a gasket, the key is to use a thin layer of it so in the case of water pump or thermostat housing gaskets, LESS is more as they say. Just a thin thin layer if the product even if it allows for that as its hard to get some of these silicones spread thin enough.

Many years ago a friend of mine who used to work as a mechanic at a ford dealership, he commented about another mechanic in that shop who was famous for using FAR too much silicone and they had an engine come back that was having issues to say the least and pulled off the valve cover this mechanic had sealed on with silicone. Most of the silicone had broken off from the inside edge and had plugged up a lot of the oil passages back down into the crank case and I would imagine what did find its way into the oil pan would soon stick to the oil intake screen. Thats a perfect example of what can happen by way over use of sealants.
02-20-2013 04:08 AM
64nailhead IMHO - that video doesn't indicate a bad head or head gasket. Again, IMO the bubbles would be much more severe and consistent or a big bubble that is cyclical following rpm's.

Did you ever get a vacuum reading at idle and say 1500 rpm's? Take a look at the attachment. It is some great info on diagnosing engine issues based on vacuum readings - thanks to wiki editors!

That surge sounds like a vacuum leak, bad IAC or bad EGR valve.

Now, guardedly, I'm going to give you some advice that is basic, at least to me. You put a new engine in this truck and reused the old (2 yr old) water pump? It is like reusing the old spark plugs as far as I'm concerned. Basically, new engine means new plugs, rotor, cap, water pump, t-stat, etc. AGAIN, IMHO!

I noticed alot of RTV around the t-stat housing. I'm not a big fan of smearing RTV around the t-stat housing. I prefer HiTack or similar because the gasket should do the sealing and excessive RTV can cause nothing but issues. It is the RTV that you can't see on the inside of the housing that can cause issues. Probably someone will chime in and disagree with me on that though.

New water pump - less than $50, get the t-stat out and see if the problem goes away by driving it back and forth to work. If it is 15-25 degrees outside, then it shouldn't blow good heat with the t-stat removed under normal driving/cruising speeds - dress warm. And CHECK THE VACUUM!

p.s. A vacuum gauge is a cheap tool that can be used on every gas engine to diagnose problems. It doesn't matter if you're working on a 64 Nailhead, 89 SBC or a 2010 LS engine - the vacuum gauge doesn't lie.

Good luck and keep us posted.
02-19-2013 09:50 PM
Northern Chevy When you do pull the thermostat and have another new one on hand, you can heat up some water on the stove and while its on the stove hang both stats into the water by some wire and compare their action and how far they open as that usually tells the story if one is bad and doesn't open near as far for the same heat being applied. Just make sure you keep track of which is the new one and which was the old one !.
02-19-2013 09:49 PM
skippy89 Here's the video with the thermostat open and at operating temperature, just click on it like the last one.
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