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James Collier Jr.

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About James Collier Jr.

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  1. Pretty much defeats the purpose of having a low oil-pressure cutout, doesn't it? That's about as bass-ackward as I've seen. If anything, the oil pressure sender should provide the ground to the relay, I would think. No oil pressure, kills the relay and it shuts down. The way you describe, as long as the relay is good the low-oil-pressure cutout is disabled. So what was the point? *smh* Folks, this is what happens when people get engineering jobs after floating through college between binge highs and get hired at $100k a year to call themselves 'engineering' things. The university local to me, most of their stupids, er, students, couldn't chew bubble gum and tie their shoelaces without falling down.
  2. Could also be a shot throttle position sensor. Is this truck one of the ones that was still TBI, or is it the PFI Vortec? I assume from OP's previous post is is a PFI model. Either way, throttle position sensors can wear out in the most common slide ranges (which depends on how it was mostly driven) and I have seen them go bad in a manner that did not set a code. Coolant temp sensors have been known to wig out and cause the injectors to drown the engine as well (most GM trucks I've seen have two, one for the gauge, and one for the computer to calculate fuel delivery and timing). And the engine doesn't have to misfire to have a bad cap or rotor. I had a 4.3 Safari once that wouldn't start after a heavy rain. Turned out the cap was cracked and allowing condensation to form inside the distributor. Started and ran fine otherwise.
  3. Good to hear, and high hopes you are correct about the pump. It certainly seems so. I can tell you that fuel pumps are the one thing you don't buy anything but OEM on, you're just asking for trouble. Even buying OEM at discount prices online can be a gamble, they are usually parts that work but do not meet OEM quality specs, and are auctioned off to resellers. Even though it may carry an OEM brand name and come in an OEM box, it will likely not perform as well, which can cause any manner of problems. Some may say 'parts is parts', but the old adage rings true -- You get what you pay for. Food for thought -- when I went through four fuel pumps in a row on my Safari, every one that failed was an AirTex. Even after correcting the crappy harness repair. Finally spent the money for a proper Delphi and never had another minute's trouble. After that, as for me, I wouldn't stick anything but true-blue Motorcraft in Ford, Delphi or Delco in GM, or Mopar in Chrysler.
  4. That sounds suspiciously like what's going on with the G-van I mentioned previously. The test lead on the firewall is easy, it will be a larger pink or black wire, usually near the relay on the firewall. It will appear to be a loan wire disconnected, but it is indeed the test lead. Jump 12V positive and the pump should run and continue to run. If it does, you have a relay or control circuit problem. You could also try jumping direct from the 12V feed at the relay, but you'll need a test light to figure out which wire it is. Most will have two sending units, one for the gauge (varying resistance for gauge reading), and one for the warning light / fuel cut-off (simple on/off switch). Some will be plumbed into the oil filter housing area, I have seen a few on the back of the block near the distributor. The one for the gauge will likely have three wires, where the other will have only two. Unplug the connector with two, see if the problem persists. It's possible you will have to jump the pins at the connector to do this, but unlikely. If there is only one with three wires, check the schematic to see which one is the warning light trigger, that will be your fuel cut-off. I WOULD, however, verify that an oil pressure problem does not exist before doing this. Factory gauge accuracy has been known to be less than stellar, especially when you're checking for a flaky sending unit in the first place.
  5. This cab and body were pretty much the same from 1988-1999, as were the Suburban / Tahoe. I don't see any reason the seat brackets and frames changed any in that time. Later models may bolt up the same as well, but I can't really confirm that for sure. One thing that could be a minor help is to know the RPO code for the seat package you are looking for. Also keep in mind, seats from a Suburban or Tahoe will recline back rather than fold forward like your existing C/K cab seats. If you regularly need to fish behind your seat for anything, that will be a problem, so I would recommend you stick to C/K cab donors to retain this feature.
  6. UPDATED: ICMs are quite common on GM HEI, especially if a previous replacement was a cheapie. I'd start with the simple stuff first and see if it runs on brake cleaner or carb cleaner. If it does, then try jumping out the test lead on the firewall. If it runs that way, you know it's a control issue, which could point to the ICM, oil pressure sensor / switch (some have both), or possibly some anti-theft system (equipped vehicles have a resistor chip in the key). Wiring problems are always a possibility, as they can be intermittent. One other thing, on TBI engines, you can see the injectors spray by removing the breather lid. This is also an easier way to spray carb cleaner or brake cleaner in.
  7. Long story short, carpenter ants burrowed into the roof and ceiling through a non-pressure-treated wood repair (in a hard-to-reach, hard-to-see spot) on one of the roof hatches, and it has taken about 7 years of leakage to figure out where the leak is. At this point, the ceiling and walls have soaked up 7 years of rainwater and have grown mold and mildew inside the walls. Also, the leak appears to have caused some electrical problems as well. Incredibly, both models suffer the same issue. To fix it right, the entire rear third and some of the front will have to be gutted and rebuilt / rewired once all the leaks have been repaired ((more than one, I just outlined the major one). Simply too much work to repair it properly, could buy another motor-home cheaper, I'm just looking for a cool way I can salvage the chassis and running gear without actually pulling the engine, and swapping it to standard C/K / Kodiak cab or the LBR kit would be a good start to building something better from scratch, though it might be easier to swap this engine / trans into something else that's in better shape. Lil Big Rigs has an FAQ that pretty much gives the generic 'see answer above' about adapting their kits to other chassis, and elaborate further that they do not research fitment to applications other than what it was built for, so I presume I would get pretty much the same thing if I call them. I'm hoping someone here has dropped a C/K / GMT400 cab on a P-chassis to confirm fitment, that will tell me what I need to know. I already have confirmation the mounts themselves are the same, it's a question of whether the locations and spacing are the same. To clarify, I currently reside in the P30 and will need to do something in the foreseeable future, whether it is buy another RV, convert a school bus / UHaul truck, or cobble together something on the P30 or P20. I would like to salvage the chassis and running gear from the existing RV at least. So I guess you could say I'm looking for ideas, in addition to whether my existing idea would work. Interesting post on another forum I just found that gives a little glimmer of hope this may work. Be advised, this IS from a model-maker's forum, but several contributors confirm that at on the real thing, least some of these P-trucks used a standard one-ton chassis, which I believe would be the case for an RV. One person alludes to a difference in lug pattern being the tell-tale sign. http://www.modelcarsmag.com/forums/topic/76803-non-trucker-questions-on-chevy-p30-availability/ One thought about the U-Haul truck conversion I touched on as an alternate, how different is a Mark IV 7.4 from an 8.1 Vortec, apart from the fuel injection? Could the 8.1's intake bolt onto the 7.4, or does the typical splayed vs vertical intake bolt issue apply there?
  8. ***UPDATED*** I'm assuming your 1993 has throttle-body injection (lower pressure than Vortec), but I am including some Vortec info as well just in case. Most older GM trucks have a fuel pump test lead on the firewall, a single, large pink or red wire, usually near the relay. If you jump this out with 12V and the pump runs, you have a fried relay or some other control function locking out the fuel pump, be it anti-theft, low oil pressure cut-out, or blown fusible link (common on C/K/Silverado/Cheyenne with fuel injection). The fusible links that blow are usually in the harness coming up the firewall behind the engine if memory serves. A few people have uploaded videos on this to YouTube. Could also be something similar to what I experienced with a Safari van. Most vehicles with fuel injection are going to have 4-6 wires going into the sending unit. Generally, only two actually go to the pump, the others are for controlling prime-up vs maintaining pressure. A lot of GM trucks, particularly those with Vortec engines, had issues with the wiring harness from the relay. Vortecs are also quite picky about fuel pressure, especially the early CPI engines. Spec calls for 62 prime pressure, 58-60 running. A mechanic I once used told me they won't run right below 55, if they run at all. And it is highly recommended to replace the harness inside the tank to the pump, no matter how good it looks or what anyone tells you. Quite common for these to be bad and look fine. You might want to undo the wiring loom on the fuel pump harness and trace it farther up to the relay, mine had a botched previous repair about 6-12 inches into the loom and tape wrap. Apparently the original wiring cooked or was damaged and the idiot that called themselves repairing it, not only left 1/8 inch of bare wire hanging out one or both ends of the butt splices they used, they also wrapped all four splices in tape together, rather than individually as they should have been. Actually melted a hole in the top of the sending unit, as it was plastic. Most modern vehicles with fuel injection also have this circuit tied in with the oil pressure switch circuit, which is supposed to cut the fuel if oil pressure drops, though I've never seen one actually do it. Another potential trouble spot if the oil pressure switch is bad or clogged with sludge (I believe the gauge is on a different sender if so equipped). I believe throttle-body-injected engines use the tach signal from the ignition control module, so if the ignition module is getting flaky, that could cause an intermittent stall / no-start condition. Vortecs have a cam position sensor in the distributor that could cause intermittent stall / no-start as well. Some may also have a crankshaft position sensor, though I believe this sensor only helps to fine-tune the fuel, as with 3800s. 1993 should be throttle-body-injected, I believe, so I do not believe that system would have either, which leaves the ICM tach signal to control the injector drivers. I know someone with a TBI-equipped G-van that has dropped their tank several times because the fuel pump keeps quitting. I keep trying to tell them what I've outlined here, but they won't listen because it fires and runs after replacing the pump (AGAIN) only to quit after a little while (AGAIN). You can confirm if the engine is losing fuel or spark by spraying carb or brake cleaner in a vacuum port and cranking. The engine should at least fire and run a short time this way, which will eliminate spark and point to fuel. Also, if the inline filter hasn't been changed in a long time, dirt or internal collapse could be blocking fuel flow, which can also overload the pump. Hope that helps!
  9. WARNING: This is going to be an odd one, and a long shot / shot in the dark to boot. I hope it's not too far off topic, but there just aren't really many forums for this. First things first. I currently am in possession of a pair of Pace Arrow motorhomes, one a 1982 on what I believe is a P20 chassis (6.2 diesel / 16-inch wheels), the other a 1983 on what I believe is a P30 chassis (7.4 gas, 19.5-inch wheels), though I have read this one is likely a P32, not a P30, which I believe only has minor suspension and brake differences. I am not sure which one I will use, or if I can even do what I have in mind. Both have severe roof problems and are too much work to repair properly to be worth it, but run great, and both are extremely low mileage (14k and 65k, respectively). I have seen several 3500s (same cab as 1500 / 2500) with the same 19.5-inch wheel and 7.4L, with an added valance of sorts between the main grille and bumper, suggesting that the cab sits higher and is on a different frame. I have also noticed similarities in rail-to-rail measurements between the P and C/K on chassis diagrams I have downloaded. Auto Zone shows the same body mount kit for the P and C/K for 1983. I have to wonder as well if the late-model U-Haul 26-footers are on a P30/P32 chassis. Even late-model GM cutaway cabs and cab/chassis for U-Haul, small buses and even the Kodiak MDT appear to be the same Express van cab (the G-van's replacement, which was the basis for some box trucks of its vintage). I have also noticed that some of those box trucks had a longer, more raked nose, even though it was a G-van cab. A few pics are attached -- a motorhome similiar to the larger one I have, a "high-boy" 3500 box truck with the extended valance and the same 19.5-inch wheel, and the "Lil' Kenny" kit built for the late-model C/K frame. All of this leads me to believe that a square-body or GMT400 C /K cab would mount on a P chassis with little fuss and muss. Which leads to my main question -- does anyone know if this can be done? Seems like it would work, but I'm hoping someone here has done this before or knows someone who has. I have run across a few similar projects, but could not confirm any of them were finished to the point of a running, driving (and safe) vehicle. The reason I ask such an outlandish question -- I've had a couple ideas here. One was to simply swap a cab / nose from a 73-03 C/K onto the frame. The other idea was a "Lil' Big Rig" kit (scaled down Peterbilt / Kenworth cab built for popular full-size pickup frames). In the event anyone is inspired, the Kenworth version is built specifically for GM, and can be adapted to Dodge, while the Peterbilt version is fitted for use with Ford F-series, though either can be adapted for the other. I'm thinking some modification would be necessary, as the P's steering column sits directly beside the engine. The steering box shows a different part number between the P and C/K, so I wonder if this would be the thing that makes it impossible. However, I wonder if the cab sitting lower might correct this position, or if I would need to change the column / intermediate shaft, or even the steering box itself? Any help would be greatly appreciated. I want to iron out the if's on this idea before I start tearing things apart and find out some technical snag, especially as the Lil Big RIg kits are quite pricey. Would rather have some answers before I start. Kinda thought about yanking the 7.4 and trans from the '83, starting fresh with a used U-Haul, and saving the 7.4 for when the U-Haul's 8.1 gives up. Might be easier, but I like the idea of using what I have if I can. Thanks in advance for any help or advice.
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