Whenever I turn on the A/C, the truck's SES, Brake, and Water in Fuel lights all illuminate. The SES stays solid even after i turn off the A/C however the rest just flicker....


It's been to the AC shop once already for this and they couldn't figure out what was wrong...


Last night after filling back up, the truck would severely stumble when the AC was turned on, but never with it off...


Anyone got some C4 so I can put this truck out of it's misery?? My 4runner with 255,000 miles has a LOT less issues than this damn thing....

Any ideas? Certainly someone else out there has had this problem before....

Definately a short somewhere. Those can be pretty hard to find. Out of curiosity, do you do any of your own work on your truck? I honestly couldn't imagine having a shop do all the work on my '95 6.5TD Burb. I would go broke. Hell, I have spent over $2000 in parts alone since buying this rig 2 months ago. And you are right, these things are a heep.

Nope in all forums yours is 1st I've seen to report this problem, looks suspiciously like a problem in wiring, start going over the engine bay in detail looking for broken or severly corroded grounds. Pull the plug on the AC clutch and see if it is anyway tied to the AC command or happening when clutch tries to power up and engage, unplugging AC will still issur command for AC on but compressor won't pull in.

Which plug do I pull to do this? Red circled one or blue circled one?


http://memimage.cardomain.net/member_img_a/25876_309_full.jpg


Do you know off hand where all or most of the grounds are that I can check?


Thanks man

I would start with the wiring harness where it comes out of the firewall just below the A/C reciever/dryer. Make sure the wires arn't fused together by heat. The braided cable ground gets ditry and can be upgraded to a larger copper wind with sheath.

10-4 and thank you!!


Will do after the AC shop gets done doing some warantee work on a messup on their last repair.


(After about 45 min of continually running, the A/C looses all output, what little air comes out is cold, but no output volume and then it comes back after another good 30 min. All at highway speed, engine at 2700 rpm....)

Definately a short somewhere. Those can be pretty hard to find. Out of curiosity, do you do any of your own work on your truck? I honestly couldn't imagine having a shop do all the work on my '95 6.5TD Burb. I would go broke. Hell, I have spent over $2000 in parts alone since buying this rig 2 months ago. And you are right, these things are a heep.


Actually my truck is a 2nd gen 1990 4runner. This is my mom's truck that I'm trying to get running straight again. I still dont understand how everyone mom took the thing to missed the grenaded vacuum pump earlier... (I diagnosed and fixed that myself) Up until now, the only thing dad ever did to the truck was change the oil and various other fluids like diff, tranny and coolant, the rest of the time it'd be going in for a shot lift pump, 3rd injector pump, basic BS that shouldn't go wrong in the first place but we still have to pay out the nose for....diesel fuel systems scare me as how you absolutely cant get any air in the injectors....or injector pump...Edited by: Bumpin' Yota

Sounds like the a/c shop had a bad part from the get go. We just had one of those on here this summer. Changed out a low pressure and it (the new one) stuck. It would run the compressor constantly until it froze the coil up. Pretty easy fix actually.


It sounds weird that you've had 3 injection pumps on this thing. If they had been working on this thing right the first time, you should not have had pump #3 put on. The 94's were the first of the electronic injection pumps put out. So 94's and 95's were the gienney pigs. The had steel rollers in the pump, which would pit, and, sometimes send the metal particals to the fuel tank. Thusly, creating a whole new headache of cleaning the fuel system.


Check out that engine ground between the passenger side head and fire wall. (The braided one) That will goof up your ground to your ECM, and make that dashboard light up like a pin ball machine.

Took it to the AC shop this am, and in front of us the AC clutch started disengaging/reengaging sportically. (AC and engine on.) He claims that's what happens and that it is from low voltage. Well the batteries are sitting at 12.8v (kinda low floating charge) and with the alt turning they sit at 13.4 while the alt is charging to 14.1 so this indicates that the GM under hood wires are insufficient, but that's not the main problem....


On the AC compressor I measured the DCV on the blue circled plug and that varies from 11.8v to 12.3v very quickly. It actually cycles at about 3hz from 11.8 up to 12.3v and back down again....odd


Im left thinking wiring harness issues.....I'm gonna poke around in the engine bay a bit to see if I can find anything interesting like a loose wire or a severed head....lolEdited by: Bumpin' Yota

First thing I would do is get another AC shop.


Your lose of cooling after 45 min. and the short cycling of the AC clutch are classic indications of a low charge and if your shop can not pick up on that they never passed AC 101. The lose of cooling at road speeds indicates the coil is freezing over from lack of gas. The short cycleing at idle is the same thing. Anyone with a set of gauages could conferm this.


As for your electrical problem I would look in the areas the AC shop worked for pinched wire that may be shorting to the instrument lights.

Well as for the dash lights flickering, I found that cause - and it wasn't a severed head! (Damn! lol) The ground on the rearmost upper intake stud on the passenger side was broken off. Fixed that and BOOM no more dash lights flickering like a pinball machine!http://dieselplace.com/forum/uploads/BumpinYota/2004-10-27_131222_DSCF0521lowResolution.jpg


I also grounded the case of the alt to the driver's side battery with 1/0ga and now the charging alt is only 0.3v higher than the batteries at full electrical load. Next I'm going to upgrade the chargine wire with some 1/0ga.


Low gas charge huh? Hmmm they supposedly just cleaned out the evaporator, but i dont know if they checked or recharged the system... Ill dig up the reciept and find out...

thanks for the help guys i really appreciate it!!

yota,


Do you have an egr boss on the upper intake?


http://www.dieselplace.com/forum/uploads/quantummechanic/2004-10-27_175147_bosscutout.jpg


That's the aluminum I cut into in this picture. If you do you have a restrictive cast web inside that's restricting airflow.


http://www.dieselplace.com/forum/uploads/quantummechanic/2004-10-27_175730_boost.jpg


This is what it looks like after you've removed the aluminum web and most of the center colum.

This past weekend I cut the webbing out of my 'S' upper intake manifold...and when I took it for a drive afterwards, I noticed that I could no longer peg the gauge to 15psi, it would come up just shy of 14 no matter what I did. My theory is that since my gauge was tapped in to the plenum directly above the webbing, that by removing it, it made enough difference to make the gauge read less pressure because of lower resistance to the air passing through the now greatly enlarged chamber. No noticeable performance difference, boost gauge climbs just a hair slower, but as I figure, the boost in the actual intake manifold is actually climbing faster, intake restriction is decreased and my gauge is reading pressure more accurately than before all by removing the casting that was restricting airflow.

Do you have a metal shim on the lower or just the gasket?

TDG,


What I found after doing mine was I needed to block off EGR completely with 20 ga sheet metal between EGR and where it mounts to the upper, and a little red RTV, also did you replace, the silver "donut" gasket between upper & lower on the mouth of the EGR tower, you will leak some of your boost there, it's a 1 time use crush gasket that does not lend itself after 1st forming to being reused, as far as boost tap I ran mine in 2 places at 1st in the inlet elbow, then in the back corner, made no difference on reading. If you tap make a plate to replace EGR valve & tap it dead center you will read exhaust pressure to turbo, with a S manifold.

I also grounded the case of the alt to the driver's side battery with 1/0ga and now the charging alt is only 0.3v higher than the batteries at full electrical load. Next I'm going to upgrade the chargine wire with some 1/0ga.


Low gas charge huh? Hmmm they supposedly just cleaned out the evaporator, but i dont know if they checked or recharged the system... Ill dig up the reciept and find out...





Another thing that will help charging that works for me get a negative battery cable (Black) so you don't confuse folks, with 2 ring lugs each end connect 1 lug to the frame somewhere and the other end to the back mounting stud of the alternator, the GM factory engine to frame straps are hard to see and you don't know when it's broke until you start having problems. The extra GND I'm proposing pust a better than factory gnd on it out in the open where you can eyeball it from time to time.


How old are your Batts, dead cells in 1 will reduce ability of the other to carry the load; if its been a while or you don't know for sure think about changing them, poor ground probably did not help charging circuit either, batteries are best changed in pairs, and if possible look on the mfg date stamp it the side of the batt, get 2 batts made pretty close time to each other.


On the AC, they should have flushed the system and replaced the orifice & dryer if a professional shop, look for those charges on the bill, crud in the orifice located in the (condenser inlet finned thing in front of the radiator) will reduce cooling caqpability, low freon will cause evaporator other finned thing in cab in blower air box to ice upand give no flow.


As Howie says really need to run by another shop and have them put on a set of A/C gages to know what is happening for sure. Did you say 14 oz of oil seems like an awful lot 4-5 oz is what I remember last one I changed. Is this a R-134 conversion?


BTW for future reference the plug for the clutch is the front one, if you ever have a clutch burn up or the AC compressor locks up on you pull that plug so you don't inadvertantly send power to it and maybe start an electrical fair, the back plug is a pressure switch for high pressure IIRC, low is on the dryer (That correct????)Edited by: Turbine Doc

QM


Looking at some pic's backgrounds I can make out that boss for an EGR on the intake. The truck has no EGR however, as it's an L65 motor and I dont see anything attached to the boss. How do I remove all that aluminum in there and have you noticed any change to doing this?


TD


That's basically what I'm going to end up doing and then some, I just ran out of 1/0ga and 2/0ga crimp lugs. The batteries are brand new, same type, model, date, and even next to each other on the same level of the pallate. And the "14" was in refrence to the alternator's charging level - it's only charging to 14.0 volts cold instead of 14.4 or more, and 13.7 volts when hot.


This truck will be exercised this weekend for a while so I wanna see if the AC does it again, now that I've rectified most of this truck's problems....lol Though i suspect the low freon (?) level even after they supposedly completely recharged it....





btw - what would make this diesel suddenly stumble that could be in the fuel? Water, bacteria, or sludge? The truck was running STRONG the other night, 0-60 in about 10 sec or so, I filled 'er up and she damn near died at idle several times. Still doing it periodically when driving now.... I see the write up for the 6.6L fuel filter swap, but how do I do the swap for this 6.5L?

Look for OPS thread in FAQs to TS fuel pump & pwr, if fuel pump isn't problem may be PMD, but lets do basics 1st. Fuel filt is dead center rear of engine, on front of engine is bowl drain valve (brass with chrome tee handle), open it and drain bowl, open vent on top of filt bowl turns CCW to open, black collar around filter body top unthreads CCW also and allows you to get top of bowl off. Pull element out, clean crud out of bottom of bowl, make sure plastic "last ditch" screen stays in bowl not inside removed filter.


I think I got the 14 oz oil cornfused with another AC thread on my mind

That stumble problem, check to see if you have a vacuum in the tank. The fuel caps are to be VENTED, and not allow vacuum to form in the tank. Mine would build more and more vacuum, the longer it ran, and until the engine was starving for fuel. Started out great, but dewindled down after the first few miles. Cheap, and quick check.


As for the a/c: Now that you've corrected the wiring issues, see about your clutch pulling in. Does it pull in and stay engaged the whole time, or does it cycle? If it cycles at idle, does it do in relatively short bursts? If it stays in all the time, sounds like stuck LP switch, which causes the coils to freeze up. If it does the quick little bursts of engagement, I'd lean toward low on charge. With a pressure switch setup, it is much more difficult for the coil to freeze up, unless the switch is stuck ON.

Yota,


Lets start another thread on the stumble problem, keep this thread as an AC post, will help when someone has a problem and searches for info, if stumble is hidden in this AC post search engine may not find the info that might be the missing bit of info for someone to say "Eureka" that is my problem exactly, now I know how to fix it.

Look for OPS thread in FAQs to TS fuel pump & pwr, if fuel pump isn't problem may be PMD, but lets do basics 1st. Fuel filt is dead center rear of engine, on front of engine is bowl drain valve (brass with chrome tee handle), open it and drain bowl, open vent on top of filt bowl turns CCW to open, black collar around filter body top unthreads CCW also and allows you to get top of bowl off. Pull element out, clean crud out of bottom of bowl, make sure plastic "last ditch" screen stays in bowl not inside removed filter.


The replace the fuel filter, and then what fill the bowl up with diesel manually? How do I keep air out of they system?


Making new postEdited by: Bumpin' Yota