[ImperialCrown]

Next time this happens take a look under the air cleaner lid, down inside the throttle body for fuel drips, puddles or wetness. An injector or injector/pressure regulator o-ring seal may be leaking causing the intermittant richness and flooding.

 

[zrxkawboy]

+1 to what IC said. Check fuel pressure both while running and to see if it holds after shutdown.

 

[88RamCharger]

Well, after spending some time under the hood I can tell you I completely hate the TBI system on this truck. What a complete frecking mess. It is also the cause of my current problem. For some reason one of the injectors is spraying gas like it's trying to feed a frecking top fuel dragster. I quite frankly was looking for an excuse to rebuild the old 318 and this seems as good a time as any. The steering box has been pulled and placed into the old pickup for the time being. The old girl seems more than happy about being the number one horse in my stable again. Over 440k miles and you'd think it was still '85 when my old man brought her home the way she runs. Sure she may not have any fancy power options like these new trucks, but she starts every time I turn the key and hasn't met a snow storm yet that can stop her. Unlike the RamCharger that's quickly turning into the ugly step-sister :angry2:


Rather than make another thread I have a few questions about this rebuild. If I understand correctly I can just bolt up the 4bbl intake and carb I have handy so I can scrap this TBI system? Also, since I plan on installing headers, what's the difference between the long tubes and the shorties?

 

[dana44]

Physically, on the headers the difference is about 18inches to 32-34 inches in length. Not really needed for a street vehicle, dual exhaust will give you just as much power in a stock, or near stock application, headers don't really start working until you get above 4500rpm. 2.25 - 2.5 inch dual exhaust with H pipe connecting them together is much more efficient for the street every time.

Now the 4bbl system, you have to be concerned with the fuel system itslef. TBI runs fuel pressure of 8-14psi, depending on the vehicle, the shop manuals can say exactly. Carbs run between 4psi and 6psi, so I imagine a fuel regulator can prevent it from getting too much pressure and increasing the problem you have now. TBI rebuilding is not difficult, couple O-rings noted and a few passages to clean, that's about it. The other solution is to pull the fuel pump out of the fuel tank and add an in-line electric pump, but stay away from the little Airtech pumps, get something like a Carter or Holley electric inline fuel pump, they don't vaporlock.

 

[Dave Z]

Fuel injectors do "go bad" and they are not all THAT expensive compared with the time you'd put into converting to a carburetor. As dana44 said, the fuel pressure on TBI is VERY different from a carb. Change out your known-bad injector -- you can probably even use junkyard injectors but check the price on new ones. I've swapped injectors myself, it can be a five minute job ... and I was surprised at how little they cost in that case.

 

[valiant67]

On the 1988, it may be easier to swap a junkyard TBI rather than just service the bad injector in it.

 

[88RamCharger]

Now the 4bbl system, you have to be concerned with the fuel system itslef. TBI runs fuel pressure of 8-14psi, depending on the vehicle, the shop manuals can say exactly. Carbs run between 4psi and 6psi, so I imagine a fuel regulator can prevent it from getting too much pressure and increasing the problem you have now. TBI rebuilding is not difficult, couple O-rings noted and a few passages to clean, that's about it. The other solution is to pull the fuel pump out of the fuel tank and add an in-line electric pump, but stay away from the little Airtech pumps, get something like a Carter or Holley electric inline fuel pump, they don't vaporlock.

Yeah, I was aware of the psi difference but a pressure regulator isn't hard to come by. I'd really rather not rebuild this TBI and just go back to a carb. I've never met a first year TBI that wasn't more trouble than it was worth.

 

[dana44]

OK, as long as you know what is needed. Change to a regular electronic ignition because the computer will be haywire trying to figure out how much to advance and match the O2 sensor to the fuel pressure, so its all or nothing.

 

[88RamCharger]

The more I look at it the more I want to just rewire the whole truck. The guy who had it before me looks to have been a wannabe electrician. Would also give me a chance to replace a few gauges and really just go over the whole truck and see if there's anything else I should be aware of.

 

[dana44]

If you don't have to worry about smog, use the wiring diagram from something in the early 70s so you have the wiring for electronic ignition and whatever alternator you have (one, two or three wire), would be a whole lot easier than piecing things together, again, but make sure you use one before the LeanBurn electrical wiring diagram so you don't have to mess with that issue. With a diagram it is easy to do, then, when you get ready to wrap the wires to protect them, go to an electronics store and get three rolls of 3M cloth tape, not black electrical tape. It may not last quite as long with heat, but oil doesn't affect it and it doesn't peel apart like black tape, worth it to use, and looks nicer than the plastic tubing, which can still be used, but the ends taped up nice and stock looking. I hate that plastic stuff.

 

[ImperialCrown]

A conversion from TBI to carburetor is a step backwards. The TBI did things like diagnostics, starting, idle and fuel economy so much better than a carb ever could. If you do switch over, save your old parts in case you want to go back.
If you just have a leaking injector, repair/replace it.

 

[88RamCharger]

So, I completely forgot about this topic while wrenching away on the mighty Dodge. Thought I'd update you guys on what's been going on.

Once I really got into the truck I decided that I'd just go through the whole drivetrain and electrical system. Thankfully I had the old grey battleship truck to drive while I did this in what little spare time I had figuring if anything broke I could just pilfer it off the RamCharger until I got around to buying another. Of course, other than her basic maintaince and one blown tire, the old work horse never let me down.

The tired 318 has been completely rebuilt from the crank up. A mild .020" over-bore to clean up the walls, and a torque spec ground MoPar purple cam have been the real "performace upgrades". The PitA TBI system was traded for a 650cfm Holley 4bbl and a Edelbrock intake I picked up at a local swap for $50. The block and heads were acid washed to clean the years of gunk out of them, and the heads and intake I port matched myself because I figured it was a good time to learn. Took longer that I figured but they turned out pretty good if I do say so myself. Finished it all off with a set of Hooker 2 1/2" long tube headers into a true dual exhaust emptying just in front of the tires. I had considered using shorties but I've had several performance guys I trust tell me the long's would give me a bit more torque and that's always my aim with a truck. A new radiator with an electric fan keep the engine cool and remove the power robbing belt driven unit.

Both the 727 and the NP-241 have been rebuilt though I'm not sure either really needed it. However, the parts were cheap and it was pretty easy to do myself. I understand now why the 727 is such a reliable transmission, there's practically nothing to it!

I've ripped out the entire stock wiring harness as the gentleman that owned the truck before me had hacked the snot out of it. Once the engine was out and I got a good look at some of his "work" I was amazed the truck hadn't burned to the ground. Thankfully the guys over at Painless seem to know what they're doing and got me set up with a completely new harness that was plug and play. Didn't even cost that much which was a plus. I had planned on replacing a few guages I thought were broken. Turns out they work perfect, it was just the wiring screwing them up.

The rest of the truck got a quick going over. Some worn out bushings, fresh diff fluids, new brakes lines, and she's good to go.

All in all, even with the purchase price of the truck, I'm still into it for less than $5k. That is because of y'all on here and the great information you keep posting. Without this place I would have had to pay someone to do a lot of the work and be out a lot more money. Instead, I've learned a lot about turning a wrench, and have a truck I'm dang proud to own. Plus, out of my buddies I'm the only one that can fit 33in tires on a stock suspention without rubbing. Ha!


Due excuse the quality of the picture, my phone's camera is barely above potato status. Also excuse any spelling errors

If you look real close you can just barely make out the roof of the Honda parked next to me through the window.

 

[BlackSheep01]

That's a dang nice-looking Ramcharger, dude.

 

[TWX]

Be careful, dad's '89 Dakota suffered a fairly catastrophic engine fire because of problems with the TBI fuel injector. We still have yet to rebuild it, and he's lucky it didn't burn to the ground.

 

[dana44]

I had my 95 Dakota catch fire under the hood due to a shorted wire from the previous owner.

Nice looking truck. Had a copper colored one we used to run around in in Guam. She almost leaked more transmission fluid than she burned gas, but simply add a little more fluid and away we went!

 

[88RamCharger]

Be careful, dad's '89 Dakota suffered a fairly catastrophic engine fire because of problems with the TBI fuel injector. We still have yet to rebuild it, and he's lucky it didn't burn to the ground.

Yet another reason why I junked the TBI for a 4bbl Holley.

 

[dana44]

I don't think mine had anything to do with the TBI, it was a direct short to the alternator, I just didn't think to check it.

 

[BlackSheep01]

I know this is an old thread. I need some help. The local guys I trust are out of pocket through the long holiday weekend ... a 1982 D150 4x2 5.2 liter (318) automatic, pulling rear end, standard-cab long-bed pickup is the vehicle.
The need is for a carburetor kit. The OEM equipment is a ThermoQuad. The dealer's parts counter help looked at me and said variations on the theme of "what's that"? So ... where do I go? A performance place? Online?

 

[richd]

I use to work on 88 Dodge Rams with 318 TBI,and I loved them.They were fast and ran great.The most problems I had was the Hall effect in the distributor,and had one with a crack in the rubber line in the fuel pump that would drive for about 20-30 mins.,then die,wait a few seconds and continue until it quit again.To check the injectors,I use to flash my timing light at the injectors too check the pattern,worked good.Hope this helps.