No power on '88

[OklaBronco]

Bought a full size 88 bronco with the small v8 for my son. Knew it had some small probs, some of which we've worked on together. But I just can't seem to track down the main problem. It idles a little rough but has absolutely no power whatsoever. When I say no power, I mean it takes 300 yards to hit 45mph. Forget 70 on the highway, it just ain't happening. We've replaced the fuel filter, air filter, and even a sticky throttle cable. Read where a couple of folks had probs with their O2 sensors so I unplugged it and that didn't make a difference. We've had some strange issues with vacuum. Under high rpms, the fan output will shift from the panel to the defrost to the floor and back to the panel as the rpms lower. Not sure if that is related or not, just another fun problem.

Took it to the tranny guy and he said it is working perfectly. That is about the best news I've had since I bought it. The mechanic is more than happy to spend my money throwing parts at it to try and guess what is wrong. I can't afford to do that anymore. I've got to figure out why it is so sluggish. Any help here would be very very appreciated. [-o<

Thanks...

 

[Seabronc]

You definitely have a vacuum problem. Check there vacuum line to the air control. It comes from the main vacuum tree and then to a check valve on the vacuum reservoir,(may look like a coffee can), from there a line goes into the cabin on the passenger side. Usually that kind of problem is because you have a bad component, (like the vacuum reservoir) or a leak in one of those lines. I would suggest you go over all the vacuum lines and look for leaks. One way to detect a leaky vacuum line is to take a propane torch and open the valve, then move the tip around the vacuum lines while the engine is running. If the engine speeds up, you have found a vacuum leak where the nozzle is located.

Not sure that will solve the power problem, but work on one thing at a time and you may find it suddenly running better.

Have you checked the timing? What size tires are on it and what is the rear end gear ratio?

Good luck,

>-

 

[OklaBronco]

That is a cool way to find the vacuum leak. I'll have to try it. I've had the vacuum problem worked on twice. You see how well that went....of course the blower relocating is a lot less annoying than the sucky power. Do you think they might be related???

I haven't checked the timing yet but might not be a bad idea. The tires are big, not sure of the size. They have a lot of tread left so they are really low on my priority list. Not sure about the rear end either. Is there an easy way I can find out?

Thanks...

 

[Seabronc]

Large tires with the stock gears will usually make a truck a power dog. The easiest way I know for a quick check is to jack up the rear and put it on jack stands, put a mark on the drive shaft, turn the rear wheel 12 turn while counting the number of revs on the shaft, ( approx. 3 turns would be 3.08, 3 and 1/2 turns would be approx 3.55, etc.). You can check that against the tag on the pumpkin to see if they are the stock gears. If it is a limited slip rear end, you need someone on both sides to turn the wheel at the same time.

Good luck,

>-

 

[snowman74]

You sure it's hittin' on all eight cylinders? Check your plugs and wires, also check you injector wires. Mine was doing the same thing when my injectors weren't all firing. Runs great now that I've replaced the wiring.

Snowman74 >-

 

[OklaBronco]

You sure it's hittin' on all eight cylinders? Check your plugs and wires, also check you injector wires. Mine was doing the same thing when my injectors weren't all firing. Runs great now that I've replaced the wiring.Snowman74 >-

I'll definitely try that, too. Thanks for the suggestion. It got towed to the shop tonight from the church parking lot. The ignition broke and the key just turned freespool. If it isn't one thing it's another. :blink:

 

[snowman74]

Man, you are having some bad ju ju...

If I remember correctly, the lock cylinder in the steering wheel comes out by depressing a small spring-loaded pin on the under-side of the column. The lock just pulls out. The problem is, the lock turns a gear, which pushes some kind of control rod in the column. To fix it, you've got to take the column apart. Sound about right guys? Finding the parts shouldn't be a big deal, though.

Snowman74 >-

 

[OklaBronco]

Man, you are having some bad ju ju...If I remember correctly, the lock cylinder in the steering wheel comes out by depressing a small spring-loaded pin on the under-side of the column. The lock just pulls out. The problem is, the lock turns a gear, which pushes some kind of control rod in the column. To fix it, you've got to take the column apart. Sound about right guys? Finding the parts shouldn't be a big deal, though.

Snowman74 >-

Well, that part is fixed...allegedly. Got a call from the shop on the way out of town to a wedding so I won't find out for sure until Monday. So now I can back to the other rat-killin'.

I think I've been parking it too close to the riding mower, though. Now it has decided to be jacked. :wacko: Been one of those summers. It's just money, right?

 

[COBRA of denver]

> Check the throttle body bolts & gasket to upper manifold if cracked replace it, make sure all 4) 10MM bolts tightened to 144 - 216 IN"-Ibs. Also check upper manifold to lower manifold bolts and gasket, famous for splitting and falling apart, back 2) bolts, driver side center bolt & front 2) bolts all 1/2", passenger center bolt is a Torx 40 should all be at 15-22 Ft-Ibs torque, if you have to replace this gasket it is worth the money to do a 1" spacer you get about 1-2 miles more to the gallon and a little extra horse power and torque >

this is the one i have on my 90 bronco with the 302 its made by trick flow can by at summit racing, part#TFS-51520004 18002303030

 

[OklaBronco]

It's been a while on this one. We've made a couple of trips out of town since then. Life has been hectic.

I finally found a guy that knows Bronco's. He is a Ford mechanic who has owned the exact model I own. He works out of his own shop now. The other shop told me that by replacing the broken ignition switch it would fix the problem with lack of power..... :blink: I hope they remember what it looks like, because they won't ever see it again.

Took it in to the new guy and there was a couple of probs. The tps sensor was bad and the low pressure fuel pump in the tank was bad. Replaced both of those and it is running a lot better. Only problem is then it started something new. Under a load it would knock real bad. He said it could be a bad exhaust lifter spring or the camshaft. Of course, it ended up being the camshaft. (

So, he is replacing the cam and it is supposed to be finished this weekend. I think I've bought this thing three times now! I'll wait until next summer to replace the a/c compressor...

 

[snowman74]

It's been a while on this one. We've made a couple of trips out of town since then. Life has been hectic.
I finally found a guy that knows Bronco's. He is a Ford mechanic who has owned the exact model I own. He works out of his own shop now. The other shop told me that by replacing the broken ignition switch it would fix the problem with lack of power..... :blink: I hope they remember what it looks like, because they won't ever see it again.

Took it in to the new guy and there was a couple of probs. The tps sensor was bad and the low pressure fuel pump in the tank was bad. Replaced both of those and it is running a lot better. Only problem is then it started something new. Under a load it would knock real bad. He said it could be a bad exhaust lifter spring or the camshaft. Of course, it ended up being the camshaft. (

So, he is replacing the cam and it is supposed to be finished this weekend. I think I've bought this thing three times now! I'll wait until next summer to replace the a/c compressor...

Are you kidding me? a broken ignition switch would fix the lack of power? *** kind of operation were they running there...a mechanic kindergarten? Can't wait to see what the cam does for you. You going with longer duration or more lift...or both?

Snowman74 >-

 

[OklaBronco]

Are you kidding me? a broken ignition switch would fix the lack of power? *** kind of operation were they running there...a mechanic kindergarten? Can't wait to see what the cam does for you. You going with longer duration or more lift...or both?Snowman74 >-

Yeah, I kinda wish I would have had him write it on the ticket so I could have posted it. They have done some good work for me in the past. I'm not sure how much that will continue in the future though.

I think we are going back with a stock cam. I'm out of money and need it back as soon as possible. This is my 16 year old's Bronco. While it is in the shop, I'm carpooling with the neighbor and my son is driving MY truck to school. [-o< Every time he pulls out of the driveway I feel like I'm pressing my luck. Of course now with all the repairs, his is probably worth more than mine! $-)

 

[snowman74]

Yeah, I kinda wish I would have had him write it on the ticket so I could have posted it. They have done some good work for me in the past. I'm not sure how much that will continue in the future though.
I think we are going back with a stock cam. I'm out of money and need it back as soon as possible. This is my 16 year old's Bronco. While it is in the shop, I'm carpooling with the neighbor and my son is driving MY truck to school. [-o< Every time he pulls out of the driveway I feel like I'm pressing my luck. Of course now with all the repairs, his is probably worth more than mine! $-)

You ought to cam it up at least a little...I mean, I doubt yours is worn down too badly. I'd think it would be your lifters, valves and springs that NEEDED replacing....but I don't know. You might add your vehicle information to your signature line in your profile. It helps those of us replying to your posts to know what kind of engine/truck we're dealing with. To do that, go to "My Controls" at the top of the page. Anyway, good luck to ya.

Jim

 

[snowman74]

> Check the throttle body bolts & gasket to upper manifold if cracked replace it, make sure all 4) 10MM bolts tightened to 144 - 216 IN"-Ibs. Also check upper manifold to lower manifold bolts and gasket, famous for splitting and falling apart, back 2) bolts, driver side center bolt & front 2) bolts all 1/2", passenger center bolt is a Torx 40 should all be at 15-22 Ft-Ibs torque, if you have to replace this gasket it is worth the money to do a 1" spacer you get about 1-2 miles more to the gallon and a little extra horse power and torque > this is the one i have on my 90 bronco with the 302 its made by trick flow can by at summit racing, part#TFS-51520004 18002303030

Does that spacer go between the throttle body and the upper manifold, or between the lower intake and the plenum?

 

[COBRA of denver]

goes between the plenum (Upper Manifold) and the lower manifold, kit comes with spacer, 2) gaskets and the bolts, takes about 1 1/2 hrs to put in but think its well worth the price and time

 

[OklaBronco]

/ Well we finally got the Bronco back last night. It runs great. 100% better than before. It accelerates smoothly and gets all the way up to speed. What more could you want? I guess we will own it now until my unemployed 16 year old son gets tired of buying gas for it.

The mechanic said that the engine had been rebuilt a while back, but it looked ok. My next task will be to replace the exhaust manifold. Hopefully, that will be something I can do myself.