Engine/Transmission (1994 - 1998) Stiff Throttle Pedal Resistance, Low Boost, Increased Smoke

[MMcCallie]

Something has changed about how my truck runs. Started over a couple months ago. I changed both the engine fuel filter and inline fuel filter and gained noticeable improvement. However, my fuel pedal is very stiff if i try to accelerate moderately to aggressively under low boost, low RPM.



Also, i have more black smoke out the exhaust. Possiibly less smoke right off idle but much more thereafter. In addition, i'm make less boost. I used to feel my ported stock turbo spool around 10 psi, get a little stronger in the mid teens, and really light up over 20 psi. I no longer feel these surges, power still waits to spool but is smoother and seems slightly decreased.



Power is alright, but boost is barely getting into the mid 20s, was previously going to 35 psi. Oh, my cruising EGT is usually high 700s, gauge is erratic, needs repair.



4KGSK makes the engine idle a little choppy after startup until i feather the pedal (i assume it is the GSK). Lift pump and overflow valve have been replaced this spring. I've recently bumped up my idle to over 900 to keep the a/c blowing cold.



My engine has also overheated a few times. Only this past weekend did it actually boil out at a good 270 degrees. I have finally installed a custom fan and Horton clutch which i believe will solve my cooling issues. Could the overheating have affected performance in these other ways? It seems unlikely to me.

 

[Vaughn MacKenzie]

270F overheating is very not good. That's pretty much 100 degrees above normal operating temp. You should change your engine oil right away after heating it like that. Something is not right for it to just overheat. Have you ever removed and thoroughly cleaned your radiator, and made sure you have a good fan clutch?

As far as your other issues sounds like something isn't right with your pump.

 

[MMcCallie]

It overheated mostly when off road. Would stay at 250 for hours while rock crawling up the mountains. Stock clutch didn't lock well enough and the fan didn't move enough air. The radiator is brand new since i destroyed my original because the wires from the clutch got caught.

It overheated the other day because i'd thrown my front driveshaft, breaking off the electric shifter wires that go into the transfer case, and i was stuck in 4 wheel drive low range. I had to drive in low range for over an hour to get back to town.

Then the solenoid for my fan broke apart in stop light traffic. By the time i pulled up to the garage door, i had steam boiling out the radiator, lasted nearly 20 minutes and spilled almost 3 gallons. Took over an hour just to clean up the mess.

I believe my cooling problems are now solved, perhaps i'll post about the fan and clutch. I just changed the oil a couple months ago. Guess i'll change it again now.

If the problem is in the pump, any ideas what it is? It sure seems to be supplying plenty of fuel. Smoke is usually charcoal dark gray. I have checked for boost leaks and found none. I was thinking perhaps a wasteage issue. Suggestions?

 

[Joe G.]

The stiff throttle may be a symptom of the AFC not working. If there is a boost leak or the hose to the AFC is broken the AFC will not work properly. A boost leak would also explain the black smoke. You may have to pressurize the system and use soapy water to find the boost leak.

 

[DRuder]

I have been having the same problem on my truck, at 45 to 50 after lock up on tc, when you start to accelerate from cruise speed will blow black smoke, lag on boost ,get stiff on throttle, more smoke when going up grade . have a new oem cooler, new stock turbo section and checked for leaks, no leaks at this time. the afc does not have a hose on it. Is there anything in the afc that would affect this other then it not using the hose or some other thing in the pump, pump was rebuild about 2 years ago. problem started in last month or so. Is better after the install of turbo section.

 

[Joe G.]

The hose MUST be on the AFC or it must be gutted. The AFC is a throttle stop to prevent overfueling until boost is sufficient to burn the fuel properly. If you remove the hose then boost cannot move the throttle stop out of the way. Kind of like driving with a 2 by 4 under the pedal. Boost pressure compresses a spring so the throttle stop moves. No boost or missing hose means you have only part throttle available.

 

[MMcCallie]

The other day i tried to blast up a hill and didn't get up to even 90 mph when it would have usually been over 100. Tonight i got it up to 100 but it didn't do it as readily as it used to, didn't accelerate as forcefully.

Should i install an AFC spring kit? I plan to add an HT3B and go over 500 hp and have read that the spring kit is not an ideal modification for that much power on a 215 pump.

What should i look for if there is a problem in the AFC itself? The star wheel has always been so stiff that i have hardly been able to get a couple clicks on it even using a screwdriver going through the port on top. Does that indicate a problem?

 

[Joe G.]

Could be. You can test the AFC to see if it is the problem pretty easy. Take it off. Cover the hole (duct tape works ok) to keep oil in and dirt out. Take it for a ride. If the AFC was the problem it will smoke like crazy and go a lot better. If there is not much change then look somewhere else.

 

[MMcCallie]

While checking things out i spotted oil leaking at the oil return line coming off the bottom of the turbo. The line is covered in oil and has painted things beneath it black as well.

When i rev the engine i can see smoke come from under the back part of the turbo. Not sure if it is oil burnoff or a leak from the turbo. I can't get my hand down in there. What's the easiest way to get to it? Can i just tighten the V clamp or do i need to pull the turbo? If it is an air leak i hope fixing this will ameliorate these issues.

 

[MMcCallie]

Think i found the oil leak but i'm doubtful that it will solve my problems. Looks like there are two bolts on the under side of the turbo that are leaking. Possibly a gasket as well. I can hardly fit my hand down in there and don't have stubby tools. Wastegate is in the way from underneath.

Anyone know what size those bolts are and what tools would work best to get to them? I couldn't even twist my hand around well enough to find out what size they are. The v-clamp wasn't loose but i got a few turns out of the nut, still smoking.

 

[MMcCallie]

Found out why the throttle felt stuck. The governor lever was sliding under the plate. I had Sean of TLSE Turbo Systems in Loveland, CO set it up. He did some grinding and welding on the plate i had ground to turn it into a modified #10.

I asked him if he set it up so the governor arm started against the plate or if it travelled before getting to it. He told me it was right against it. He lied. The arm had enough travel before the plate to go right under. Man, no wonder this truck ran so badly!

After some slight adjustments, i now have a lot more fuel. Hits over 20 psi almost immediately. However, i'm still only seeing 24 psi so something else needs adjusting too. Just discovered the water injection pump he installed is not working. Boy, that explains why i'm fiddling with the controller all the time and never made progress.

He kept my old pump, changed the wiring on the one he gave me so i can kind of see why it wasn't working, but i'm at a bit of a loss right now on how i might wire it or if i need to buy a new pump. This was my 3rd pump. I'm fairly certain this pump worked for a little while, there was still water in the line but nothing coming out of the pump.

I honestly cannot recommend his shop for any work. He ported my turbo telling me that i would see faster spoolup and EGTs would go down 250 degrees. Said it could possibly support 500 hp with water injection to help. I wish!

I instantly noticed my turbo took longer to spool and EGTs were still going over 1,550. I told him the next day i didn't like it. We tried it with the silencer ring reinstalled but he said it didn't run as well that way. Only thing i liked was that the turbo has never barked again. I hear a cricket like constant whistle from the turbo, especially at idle. Makes a lot of noise but didn't give me any performance by my seat of the pants.

I was never happy with any of the tuning he did and told him so but i guess after just a couple attempts, he felt no need to make it right. Odd because he claims he will do what it takes. I told him i thought the truck was less powerful than it was before he touched it. He quit returning my phone calls some time ago, though i've been as pleasant with him as even any non-disgruntled person could be.

I should also add that he and his partner told me i probably didn't need a fan shroud, but i ended up overheating above 250 F many times. We made an appointment when he was going to help me build a custom shroud several days in advance. I waited 45 minutes for him. His partner showed up acting ****** that i was there and got Sean on the phone. Sean said he forgot though his partner had just told me Sean had told him i wouldn't be coming.

I have low tolerance for lies. This was after he'd told me to buy a 2007 fan and clutch which i lost almost $100 on paying the restocking fee, even more from listing it on ebay. He had previously gotten huffy with me when i was questioning things he was telling me about the fan saying, "Matt, trust me, I know what I'm talking about, I've been doing this a long time. "

I won't add anymore, just want to make sure no one else makes the same mistake because at first, he seems like a very nice guy and probably is, but he's definitely not reliable and does not stand behind his methods.

I now need to figure out why i'm not making boost. Oh, still have to get the oil return gasket from the turbo replaced. Guess he didn't put on a new one when he reinstalled my turbo so that side of my engine is covered in oil. I'm told any qualified mechanic supposedly knows to do this... ? Guess i'll start with the wastegate.

Too many people have worked on this engine, it is a mess. Hard to find someone who doesn't just say they know what they're talking about but can actually tune a 12 valve. I'm always having to learn more and fix their mistakes. Only so much time in a day. Without the TDR, i'd be up a creek with no paddle.

 

[12V Ford]

The part about the silencer ring would have raised my flag. It doesn't make any difference with it in or out, except for the noise level.

 

[MMcCallie]

Right, that's what i've read as well. I don't know if being ported actually would make a difference without it or not.

 

[CogginsP]

Sounds like an absolute mess. Check all your boost elbows and hoses for a boost leak. If a shop is telling you that you do not need a fan shroud, FIND A NEW SHOP! Your motor WILL overheat if there is no fan shroud, no ifs ands or buts. Oh, and if a shop is telling you that your truck is running differently with a silencer ring, FIND A NEW SHOP! 24 PSI of boost sounds normal to me, especially if you guys returned the fuel back to stock.

 

[JGK]

Found out why the throttle felt stuck. The governor lever was sliding under the plate. I had Sean of TLSE Turbo Systems in Loveland, CO set it up. He did some grinding and welding on the plate i had ground to turn it into a modified #10.



I asked him if he set it up so the governor arm started against the plate or if it travelled before getting to it. He told me it was right against it. He lied. The arm had enough travel before the plate to go right under. Man, no wonder this truck ran so badly!...

MMcCallie,



For what its worth, the governor lever is SUPPOSED to go under the plate, but only during the start-up sequence. Now granted, in run mode, if its under the plate and actually hanging up on it, that's wrong.



What happens during start up is, you blip the throttle just as you hit the starter and the governor lever goes forward under the plate to about 12. 8 mm of rack travel to give extra fuel for start up. As soon as the engine catches and the revs go over about 300 rpm, the governor takes over and pulls the lever back, shifts it up, and puts it on the plate/AFC foot. That was explained to me by a Bosch Master Tech with many years experience on Bosch in-line pumps. Mine is set up that way now - though before I had the governor lever on the plate just like you - and it starts quick and runs strong with no excess pedal pressure.



I'd be suspect on the turbo porting, too, based on the other things he's said and done. You can smooth out the flow between the manifold and the turbo exhaust housing, but you only want to trim down sharp edges the gas flow can crash into. If he just hogged out a bunch of metal, you can reduce gas velocity which will have a negative impact on gas flow and, thus, turbo response.



Now as to the rest of your issues - no idea. But it sounds like you've had things way too hot way too many times. That would make me very nervous.



-Jay

 

[MMcCallie]

Another thing TLSE told me is that the pyrometer is the last gauge they ever look at. They said they're not afraid to see over 1,600 degrees during a hard pull. They said that's just the temperature of the gases exiting, not the temperature of the metal. It didn't make sense to me that they would have redefined the wheel in regards to heat tolerances. The partner was even saying he doesn't mind seeing 1,600 frequently, not just on the track.

I don't care for such a noisy turbo, especially one that isn't giving me performance. As far as the plate, it was definitely hanging underneath while running. I've had no more stiff throttle since i messed with the plate. I haven't adjusted the governor yet. When it moves forward with the engine off it moves up to the bottom of the plate and climbs up. On it, not below it. I've never adjusted the governor so i'm not sure what to do.

I've also never adjusted the wastegate but i assume that's why i'm seeing so little boost. I have my plate all the way forward, as well as the AFC. The star wheel is so stiff i have not been able to turn it in either direction, even using a screwdriver to push on the teeth of the gear.

I've ruled out a boost hose leak by spraying starting fluid all around the hoses while the engine was running and it didn't raise the idle. I haven't traced the hoses to the AFC yet, but all new hoses were installed last fall.

This turbo was making over 42 psi before anyone else touched it so i know i can do better than 24 psi. It sill smokes hard and has tons of fuel. Just this summer i was previously seeing 35 psi. With 90 hp injectors and the 913 pump setup full forward i know i should be seeing higher numbers, easily above 30 psi. So much for my ported WH1C running as well as a 62/12.