jasonjsmith1986

i am working on a TPI 305 86 T/A.... I have done a ton of work on the car, but now it seems like i have run into a brick wall... I am thinking that it is the timing, so I will cut to the chase and give you the scenario.....

I had to replace the oil pan and timing cover, and the guy that was helping me suggested that we change the timing gear and chain while we had it broke down, mainly cause the chain had a little too much slack in it. I went called the parts store and ordered a new one, it came in and i replace it, lining the dots up 6 oclock 12 oclock, then i put everything back together, and went to check the timing, and the mark would not even reach the timing guide on the timing chain cover. The car will crank up and run and drive.... Which make absolutely no sense.

The only issue that I am having is after the car warms up, it starts to skip, you can hear it spit and sputter in the exhaust, and it pops loudly from time to time, nothing consistent. Also it idles high ( around 1,500 rpm). and when you turn it off, it takes it longer to start up, like you have to hold the key down longer before it fires. and it burns rich.... As far as a cold start, it idles around 800-900 rpm, no spitting and sputtering, no popping... doesn't smell to be running rich... to me it runs GREAT. Driving, it runs great, Cold or Hot....

Could this be a defecting timing gear set, or could I have possibly done something wrong when replacing the timing gear set?



(some other background is that I have had the module tested, replace plug wired, and plugs... replace the IAC Valve and TPS, and other stuff not pertaining to how the motor runs...)

305sbc

iTrader: (3)

Could you please clarify your first statement above? That was confusing.

did you disconnect the EST connector while setting/checking your timing?
You have to do that or you cannot read the timing correctly or set it correctly.


Other things like IAC and TPS absolutely have major effect on how the engine runs. There are proper set-up procedures for each.

Most of the information for doing these tasks is listed at technical links, linked from the home-page of this site.

jasonjsmith1986

I disconnected the EST wire while setting the timing. What i was referring to is that once I changed the timing gear set, i replace the timing cover, oil pan, water pump, etc, and when i started to set the timing (rotating the distributor with a timing light on) the line on the harmonic balancer would not rotate around enough to reach the guide that is bolted on the timing cover....


I hooked the volt meter up to the TPS and set it accordingly to Repair Manual. I also checked the length of the stem (or whatever you would call it) on the IAC and it was fine as well..

305sbc

iTrader: (3)

Alright, so the EST was disconnected while you were looking at your damper mark, and it was not near your timing-tab on the timing-cover ?

I'm not exactly sure how you got to the point of setting your timing, because installing a new timing chain does not change your ignition timing setting as long as the cam is still timed correctly with the crank.

Make sure your timing light signal probe is in fact on the #1 plug wire (driver-side front). Make sure the EST is disconnected so that there is no advance added, - damper mark shouldn't move when you rev the engine. Make sure you have the correct timing-cover and timing-tab to match the damper you are using, - TDC mark should line up with timing-tab with #1 piston at actual TDC. Make sure the damper's inertia ring hasn't slipped in relation to the damper hub.

After that I don't know what to suggest besides pulling the chain back off and checking it against actual TDC. Some crank gears have 3 keyways that each have a timing mark on the front of the gear, and that can be confusing sometimes during installation, especially if you lose the instruction sheet or if it's in Chinese.

ninetyone

iTrader: (2)

did u have the distributor out?

jasonjsmith1986

The Damper Mark wouldnt rotate farther than straight up
This is the style of timing cover that I used when I replace the old one. They looked exactly the same. When I took the old one off, it of course had the timing-tab that went in the two right holes above the peg hole that i am using to check the time with.

I am sure that it was plug #1....I checked that over 10 times when It wouldnt time right. The reason that I checked the timing to begin with is cause it was way off.... like 4-6 degrees.... I guess whoever had the car before I did didnt set it right. The damper doesnt move when I rev the engine and the crank gear that I put on only had one keyway on it and as far at the Chinese instructions, there were none.. LOL!

No i haven't taken the distributor out... That was going to be one of my next options, replacing it, but that is a lot of money to play a guessing game with not knowing if that is my problem

ninetyone

iTrader: (2)

I know for a fact that the 305's had the timing mark at 12 o'clock and the 350 engines had it at 2 o'clock. I would just give the car what it wants. In other words set the timing to where you hear pinging and then back it off 2 degrees and check it again. If you still get knocks , knock it down 2 more degrees. Just give the car what it wants.

ninetyone

iTrader: (2)

You could always get an adjustable timing tab pointer. You just need to set your engine to TDC. Use a piece of wire if you dont have a piston stop. Then turn the engine clockwise until it stops, mark your balancer there. Then turn the engine counter clockwise until it stops again and mark it there. Split the difference and make a mark in the middle. That is TDC. Also at this point your distributor rotor should be pointing to no. 1. If not take your dist out and re mount it so it is. Then at this point attach your timing pointer and adjust so that 0 on the new pointer is lining up to the middle mark you made on the balancer and that is it! That is your true TDC. Then try and set the timing again.

jasonjsmith1986

That is pretty much what I did... I would just lightly turn the distributor one way or another until is sounded like it ran the best...

This weird thing with this is that like i was saying when the car starts warming up, i mean as soon as the temperature gauge starts moving, the cars idle increases to about 1,500 rpm, which is way high for idle and you can hear the car skipping/misfiring in the exhaust, every now and then it will pop real loud (almost like a back fire), and it starts burning real real rich... I mean you can smell a big difference!

But, while driving, its great... lots of power, no hesitation...

ninetyone

iTrader: (2)

Coolant temp sensor plays a role also, a bad one will make it run crappy and overly rich. Also, i would not rule out a bad ecm either. How are all of your injectors? Have you ohmed them? You are TPI right?

jasonjsmith1986

Yeah I am TPI... I haven't ohmed them... I will put that on my check list! Thanks for your input!

The Coolant temp sensor, is that the one that is below the driver side manifold, or one of the ones directly under the Throttle body?

ninetyone

iTrader: (2)

under the TB

ninetyone

iTrader: (2)

prob a bad CTS

jasonjsmith1986

Thanks ALOT! You've been a big help! I have to move this weekend, so got to put the car on the back burner.. I will post results from changing the CTS as soon as I get it changed!

jasonjsmith1986

Okay... sorry for just now posting the results, but after moving and weekends of horrible weather, I finally got to change out the CTS... It definitely helped a lot! Still got some tweaking/other small problems to figure out i think... Quite possibly, I think that the MAF Sensor needs to be cleaner or replaced. The car actually idles better with the MAF sensor unplugged. It idles higher and burns richer with it plugged in. I found this out accidentally when i was putting everything back together and forgot to plug it back in before I started the car. I am going to purchase some MAF sensor cleaner and try that before I throw some money on a new one... Is there anyway to test one or do i just need to fork out some dough for a new one? Also, it still has that small, inconsistent skip that is driving me crazy...

rusty vango

your statement about lining the timing gears up "at 6 & 12 " might be your issue here.the dimples in the gears are supposed to right next to each other,the one on the crank points up ,the one on the cam gear points down

rongreen

iTrader: (1)

In addition to the above dot alignment crank at 12 and cam at 6 camshaft locator pin should be at approximately the 3-4 position if cam is phased correctly.

305sbc

iTrader: (3)

I certainly don't want to add confusion to this issue, but my 1986 305 TPI came originally with a normal timing tab (not the tube) in the 2 o'clock position, and that's what I've kept on it since I still have the original cover, and I've verified actual TDC several times over the years.

The alternate style covers must need the matching damper, because all the cranks I've seen are keyed the same for TDC and cam timing purposes.

rongreen

iTrader: (1)

Correct the early timing mark locations were changed on later model SBC.

jasonjsmith1986

I am pretty sure that is how i have the gears lined up.. When I installed them, the dimples were right next to each other...

I definitely see your point here... The cover that was on this car was the tube style cover... and the timing lined up perfect. I had to change the cover because someone obviously at some point tried to pry the timing cover off the car or something similar because the lower lip was bent out and was filled with silicon to try and stop it from leaking... i dont know what they were thinking.. lol!

I replaced it with a similar cover... There might be some small different detail that I can't see, but they looked identical. I would think that replacing it with the same style cover wouldn't make the timing not able to set, Do you?

rongreen

iTrader: (1)

If you use the postive stop method explained above TDC should correspond with the zero alignment of your damper/cover tab if they do not align at TDC the cover tab/damper are not matched then it is probally the wrong cover.

If I understand your reply your marker was located above the right cover dowel pin which is the late model location the one pictured is muuch further counter clockwise trying to zero that tab would surely advance the timing too far.

an old shade tree method of getting the timing close is to connect a vaccum gauge to a source that reads at idle and rotate distributor until highest vaccum reading is read EST disconnected.

jasonjsmith1986

You are correct on the location of the marker, but it is a bracket-style that bolts on with the two nearest bolts above the right dowel pin. That is the way it was when i took the "original" off. I tried to do everything exactly the way it was before, but in my mind, as much as i have had to fix, it probably wasn't right to begin with. I am to the point that i am going to have to take everything back apart and start over as far as the timing is concerned. I was trying to avoid that, but as we all know, sometimes we have to take two steps back to go one step forward.

I might try your shade tree method first tho.. Just to see how close the timing is at this point. Thanks to everyone for your input. I have been working on getting this thing back on the road for nearly a year... I have been ready to enjoy it some...

rongreen

iTrader: (1)

Any luck with the timing issue yet?

jasonjsmith1986

I haven't had time to check it yet... I work about 70 hours a week so my time getting to work on my car is limited right now. Thank god for the time change this weekend! I will work on it Sunday pretty heavy..I should have an update Sunday afternoon or Monday...

rongreen

iTrader: (1)

OK

jasonjsmith1986

I still didn't get to check the timing on the car... Thanks to the time change I am going to get out there sometime this week and work on it some... Just to check the timing.... gonna try cleaning the mass air flow sensor as well to see if i can bypass not having to buy one.... I seriously think this one might be screwed tho.. the previous owner had it installed backwards... :/ go figure!

LTL_DMON

iTrader: (1)

Hmmm... the timing seemed to be an issue with this car, I thought I had it corrected. After working with this car and reading what you have found, clearly who ever own this car before us knew nothing about how to work on one... I hope everything works out for you. (I found the TPI Plenum Extension it's yours if you want it.)