Well, the never-ending saga continues with my 86 TA. Before I start, here is the list of what has been changed in the last year to year and a half: ECM(twice), PROM(updated delco prom), MAFS, MAFS Power Relay, MAFS Burnoff Relay, EGR, TPS, IAC, Coolant Temp Sensor, 02 sensor(4x), Oil sender/switch, Stoplight Switch, Fuel Filter, Air Filter, PCV Valve, Plugs(to ac delco b/c bosch blows), Wires(see sig), Cap, Rotor, Virtually all vacumn hoses, exhaust(see sig). On top of all this, i keep routine maininence on it regularly. I run fuel injection cleaner through it @ every oil change(3000mi) and I use chevron techron for that. It has 148,xxx miles on it. Friday, a friend advanced the timing by using a vacumn guage a bit...that helped in shortterm. Now, it pings at highway speeds when really getting on it. So I have to set that back to where it was. Anyway, maybe someone can help give me an idea as to what is going on. The light at work....from the parking lot to the main road....its on a downslope....almost everytime i stop there waiting for the light to change in the overdrive gear, my engine starts to go "vrrrrrrrr.....vrrrrrrrr......vrrrrrrrr" with the rpm's going from 8-900 down to 300 and then back up again and repeating this pattern a few times over....then it stops doing that, the idle stays somewhere around 500 and the check engine light comes on(code 44-lean).....after i start moving and start going up the hill facing me on the main road now, the light goes out, and doenst come back on again. Also, when I'm stopped somewhere....a light, stopsign.....and I go to hit the gas from a stand-still, the car hesitates....stumbles a bit at first...almost like a miss....then if i keep my foot on it, it will pick up like a bat out of hell. This is no good when you're trying to cross an intersection with no lights and two-way traffic. I need the power from the standstill. This all was happening when the vacumn was not advanced like it is now. As said above, I've pretty much replaced everything that had to do with AIR for the most part. What's left? The only thing I can think of that could cause this now are Injectors, Fuel Pump...and maybe timing chain. I cant think of anything else that could be wrong. If anyone has some ideas...any of you mechanics out there.....somebody....I've come this far, spent over $2200 dollars in repairs alone on this car since the end of this past April.....I just want it to run right for a change. I'm calling my mechanic as well....thanks for any advice you guys might have.

 

Anynone want to take a stab? This is frustrating beyond belief...

 

I'll take a shot... but in all seriousness dont get your hopes up. This sounds like a job for the all mighty VADER. I once read about a car that had lack of power at times and would stall out here and there. A lot had been replaced...tune up parts..fuel pump, ECM ect ect. The problem turned out to be that an oil change sticker was "floating" around in "intake boot." Im talking about the piece where the MAF sensor connects into. That oil change sticker screwed up the readiing of the MAF sensor and in turn was giving the ECM false information. Could this be your problem.....probably not but it couldnt hurt to look. Good Luck.

Dan

 

At this point, I'll take any suggestions....I've changed so many parts, but mostly are related to air...thats why i'm leaning towards a fuel problem at this point. However, to answer your question, I've never had an oil sticker under the hood of my car. I've actually never had an oil sticker anywhere near that car, b/c I've always done the oil changes myself. And, this past weekend, I did a coolant flush on the motor, so I had all the ducting that has to do with the MAFS off...and I also looked at the air filter to make sure it was still clean.....so, no oil sticker. Thanks for responding though Dan. I appreciate it. Anyone else got any ideas? Vader....you out there?

 

Anyone else? Anyone?

 

Can you monitor fuel pressure when it happens...just wondering if the pickup on the pump fell off?

 

ok your running lean, and your timing is advanced... and im guessing but i your ecm is no longer controling the dizzy correct?
well, You do you have a AFPR? scanning tools? I would check if your injectors are getting power. If the dizzy no longer controled by the ecm, then it cant pull timing or advance it if need be. Your pinging could be caused from you advancing it to far and at WOT your not getting the propper fuel in there, and causing preignition. Other then checking the injectors are getting power and checking out the timing... i would have to venture its something with your timing belt skipping. I would check that out.

 

I dont have scanning tools or fuel pressure tools.....I called my mechanic...he isnt in, and is supposed to call me back. The pinging I know is caused by advancing it too far, because it didnt ping like that till after we advanced the timing...so that has to be reset to what it was before. I wont be able to monitor the fuel pressure till after my mechanic gets the car into his hands. But thanks for the ideas guys....I will look at the timing belt/chain to see whats going on with that thing. Any other ideas would be greatly appreciated as well. I hope it isnt my injectors....that would be really expensive to replace them.

 

Just another thought, since it occurs when you stop, could be a vacuum leak in the brakebooster area.

 

Here is an easy way to check the injectors, IF your car stumbles when your revving it in park. Take the air ducting loose from the MAF and have a friend cover half the opening with a board or his hand and then rev it up. If the car improves you most likely have a fuel problem. I would first monitor the fuel pressure. It should stay between 38 and 45 psi at all times. Next stop would be the injectors. If they are bad I would purchase a set of Ford racing injectors and an adjustable fuel pressure regulator. Total 300 dollar invest for a noticeable improvemnet in performance.

 

Good point, however, i must have gone over every vacumn line 10 times and replaced just about every single one of them....and i paid particular attention to this area as well.

DaceCS1...

The car DOES stumble when i rev it in park. It still does that hesitation like it misses....rev it up, and its something like "vrrr.....vrrrrrrrrrrrrrrrrrrrrrrrroommm......" as if it rev's twice in the same rev(stepping on the gas once), if you can follow what i mean. This happens in park and neutral. I know there is a delay in revving b/c of the throttle body springs and such, but thats a spilit second...what its doing isnt the same thing....there shouldnt be virtutally two seperate revs, one shorter than the other when revving the car or hitting the gas. Could you be more specific in your test of the fuel? Its a good idea...but you say: So i take the plastic piece between the MAF and the intake off, and cover half of the air ducting thats left (not the MAF) with a board or his hand, and then rev it up and see if it makes a difference? And if its BETTER, then you're saying i MOST LIKELY have a fuel problem? Ok....will give that a shot, thanks for the idea. My mechanic is supposed to call me back and let me know whats going on. Before I do any of this, i have to set back the timing to what it used to be. Its funny though.....i had the fuel pressure checked early this year.....and it was good. We checked it at that node on the fuel rail by the distributor cap. I was just curious of that one thing i wrote was something significant...the fact that on that downslope, my car surges up and down from around 800 to 300 and back , and then my check engine comes on, gives me code 44(lean), and when i start moving again, the light goes off and doenst come back...and it only happens on this downslope...there has to be something significant about that. Also, there is detonation now-which i forgot to mention. It started before we advanced the timing...I noticed it when we were doing the coolant flush. Sounds like of like a bass drum in the exhaust....does not happen constantly, but it happens enough to notice in idle or park....you hear the exhaust, and then you hear something like as if someone was inside there with a bass drum hitting it a couple times....its very frequent but not constant. I'm trying to be as thourogh as i can be. It wasnt as frequent before we advanced the timing, i dont think. I hope this gives more clues....but i will do that test you mentioned hopefully tomorow possibly. Let me know what you think of what I mentioned in this post. Thanks again for your help guys!

 

Ohhh...and what about Accel injectors in case i need to replace the injectors? I was looking at them in Jegs, and i might be able to get them from work for less b/c of a discount....how are those, and what kind of lbs/hr do i want to run with a stock ecm and prom? Can i go higher without modifying the ecm or prom as far as lbs/hr or not, and whats a good recommeded lbs/hr for a stock 305 with just the mods i have on the car now?

 

Get the stock 19 lb. injector size, you're motor is mild and doesn't need anything bigger. Accel makes them i think for 225.

 

Thanks for the info on the injectors....anyone else have ideas about the probs i'm having with the car?

 

im in the same predicament (spelling?). Ive replaced pretty much everything but injectors and fuel pump, still runs like crap. I'm assuming now that its a mechanical problem. When was the last time you checked your valve lash? Compression test? Those might give you some clues as to what's goin on.

 

Yea, as soon as my mechanic has some time, since he has all the tools, we're going to look at all those things. He's backed up right now. And heres another thing...one day it runs great, the next day it runs like crap. I also should look at the timing chain...it may be worn out. I just hope i can get this fixed. Poeple tell me "what do you expect for a 150k mile 305, that it will run like new?" No, i dont expect it to perform like it was when it was new, but I also know that even with the mileage, it should not behave this way if the car is maintained...and I do maintain it properly....its now an underlying problem.