1990 BII Hard to rev up and cuts out while driving

[vabronconut]

Ok I replaced the coil and it got just a little better, so i tryed moving the timing and it runs much better and has more power with the timing advanced. but only if i advance it to the point its hard to crank and pings like crazy. I don't believe the timing is advancing like it should. What controls spark advance and how?

the tfi controls the spark. if you are able to advance the the timing and it actually makes a difference i would think its the pick up inside the distributor. the tfi is mounted on the side of the distributor and can be taken off and taken to autozone or the like to be tested. make sure they test it a few times to be sure. if it tests good i think i would replace the pick up or the whole distributor which ever you feel more comfortable with. if it is not the distributor i think your timing chain slipped a notch and the chain and gears need replaced. but it really sounds like you did a great job of narrowing it down to the distributor.

[vabronconut]

i just read the entire post again to make sure what you did. im sorry for my post in front of this. i had a few more questio for you.

when you checked the timing chain where the dots on the gears perfectly aligned?
when you changed you timing did pull the timing plug during the change?
you said that the truck died a month before this and you changed the pickup, and then it ran fine until this latest problem?
if you arc the plug wire to a good ground(block) with a screw driver, is the arc blue or have some yellow to it?


if all your answers above are yes i would 100% without a doubt try another distributor. the ignition system is really simple in these trucks and there is not many components to them. if your able to start and run the truck but it has no power, then you advance timing and now you got power but pings at or near idle. then you are definetly right were you need to be. one of two things have happened, when you checked the timing chain and restabbed the distributor you mis timed it (which i doubt), or the distributor is truly bad. when you changed the distributor pick up did you polish the shaft near the pickup? the pick up is only one of the two pieces needed. it is the armature, and the shaft is the rotor, if the rotor is dirty or burnt, or has arcing marks or is just worn down it i will not make proper contact and poor output. you can try pulling it apart again and cleaning the shaft up, but if it has been run allot since this problem started then you probably have damaged the new stator(pickup).

hope this helps

[campcreekkennel]

Hay your not the only one with that problem my 88 BII with the 2.9 also does the same thing. It runs fine until the motor get to normal operating temp. With mine i can push the clutch in and it will only tach 4000 RPMs. I also think its a timming problem but it looks like you tried all my solutions.

[clem]

Go back to basics,air filter? I've seen some really dirty ones before. A temp sensor may cause a rich condition. Is there any smoke coming out of the tailpipe, black would indicate a rich condition, blue is burning oil and white (steam) is usually a sign of a head gasket problem. Have you had the injectors checked for proper spray pattern? Please keep us posted and good luck.

[Godzilla9992]

When I checked the timing marks, the dots lined up perfectly. I have used a couple different methods of checking the spark and its a strong blue spark. I rechecked my fuel pressure again and its now staying around 22psi at idle, but the gauge flutters allot. I have just replaced the pump when the problem first happened(it only had 15 psi), and it had 35 psi right after i replaced it. It ran the same after i replaced the pump and had the gauge hooked up showing 35 psi, so i figured that wasn't the problem. I tried clamping the return fuel line to see if the pressure would come up, but it didn't affect it. I'm planning to pull the fuel tank out again for inspection.

[vabronconut]

When I checked the timing marks, the dots lined up perfectly. I have used a couple different methods of checking the spark and its a strong blue spark. I rechecked my fuel pressure again and its now staying around 22psi at idle, but the gauge flutters allot. I have just replaced the pump when the problem first happened(it only had 15 psi), and it had 35 psi right after i replaced it. It ran the same after i replaced the pump and had the gauge hooked up showing 35 psi, so i figured that wasn't the problem. I tried clamping the return fuel line to see if the pressure would come up, but it didn't affect it. I'm planning to pull the fuel tank out again for inspection.

it sounds like you have some blockage like you are thinking. it may be a the low pressure pump in the tank, if it is no good the high pressure pump would struggle to pull fuel past it. should be easy to check by disconnecting the electrical wires to the high pressure and the output line on the fuel filter and see if it has about 5psi flow.

[texastud1983]

I'm having the same problem with my 87. I'm at wits end with this thing. I also got a MAP sensor code and changed it and no luck. I changed the IAC and the EVP sensor and still on change. I also did a tune up and just this last weekend I changed the fuel pump and filters becuase it was cutting out because the tank was full of rust. still no change........................

[clem]

Did you figure this out? Please let us know, I still think it's the air filter.

[campcreekkennel]

no its not the air filter. i have changed mine when i first bought my B2 and it still done it

[Godzilla9992]

Still no luck, haven't had the time lately. Still open to any suggestions.
The air filter is brand new, But i have tried running it with the filter cover off,
no change. I'm about ready to try a different engine, maybe a 5.0!!!

[justbowl88]

My 89 did the same thing for awhile, and it puzzled me too. I replaced the fuel pump among other things that didn't fix it. Then, just for the hell of it i put some fuel injector cleaner in the tank when it was almost empty and filled her up. I saw an immediate difference and over a 2 week period the problem went away. It still revs up pretty hard, but as soon as i put it in drive, the the rpms go where they should. This is no gaurantee fix, but its a cheap try. If you try this let me know what happens.

[vabronconut]

Still no luck, haven't had the time lately. Still open to any suggestions.
The air filter is brand new, But i have tried running it with the filter cover off,
no change. I'm about ready to try a different engine, maybe a 5.0!!!

any luck ??? keep us posted

[CarbedNotch]

You may have a cracked head. It's very common on the 2.8,2.9,3.0, and 4.0.

[clem]

Did this get sorted?

[Godzilla9992]

Alright I finally got the truck running again. It turned out that the plastic assembly that the fuel pump sits in inside the tank was bad, it was letting the fuel go straight back into the tank somehow. anyway the truck is running great, thanks to everyone that posted.