1985 Grand Am

[jayrider75]

Hey , had to do some work on secondary car..Anyway I got the thing running now ..off base and it's right on 8degrees "off base" but when i try to give gas it either stumbles or dies ..backfire type,back up the tbi. when I put it on base and im lucky to have it run at all..I moved the dist. back about 1 or 2 teeth ,so off base it's on 8 deg. but that what it needs to be on "base",and it's pretty touchy as far as moving the distributor .

[Tech II]

EXACTLY, what did you do to this car? All the work done? Was distributor ever pulled? Follow timing procedure on the emission's label?

[jayrider75]

Yes, the distributor didn't come withe the engine so I've been doing TDC the same way over and over ,finally I decided to go back a few teeth, I'll go look at the timing procedure but I'm sure I'm doing it right ,but checking never hurts right? The question still is I shouldn't see the timing mark unless it's on base right? So maybe I'm 1 tooth off?

[Tech II]

4(2.0 or 2.5) or 6(3.0) cylinder? Wires correctly on the right terminals of dist?

My memory is a little foggy on this.....does the emission label tell you to disconnect a line, or to jumper A to B in the ALDL connector, to be in base timing?

Once in base timing, then the dist should be rotated to the BTDC spec....

[jayrider75]

2.5 , wires are correct, ans it's the jumper from A to B. I can't get the thing to run long enough to check timing on Base mode,if at all.... I do have a question about my 89' 2.5 grand am ..there is a freeze plug between the block and the transmission huh.?

[Tech II]

I think you may be off a tooth......

Find the compression stroke on number 1, by having someone bump the starter, with your finger over hole of cyl #1(spark plug removed)......when you start to feel compression, stop bumping the starter, you know you are on the compression stroke, and the mark on the pulley should be close to zero on the timing mark.....now manually rotate the engine so the mark is on zero(should not be far away).......mark the side of the distributor, where the #1 terminal is on the cap.....remove cap......does that mark line up exactly with the tip of the rotor? If it doesn't, you are off a tooth or two.....

[jayrider75]

oK zero top dead has been done , went and marked where #1 should be on dist. and it was off , fixed that. Now I can start it but I have to adjust it back to start then slowly get it 8 degrees with it in base mode( while its running)..but when i turn off the engine It wont start unless i back up the dist. and forget about it running on its own..

[jayrider75]

I've had this car for a long time now and want to be sure how the dist. sits as far as are the 2 connectors supposed to be on the firewall side or next to the block? I can't find any clear pics anywhere . I feel I've been right though...near the block.

[jayrider75]

I've been looking all over for anything to help...and I found somewhere that the timing should be around 10 degrees with the aldl disconnected .Does that sound right ? I did get it to run in that degree. Revved pretty clean ,unless I bump the gas then it shuts down quickly.Also when I do have it run..one way or the other i can hear some pops (too rich?) from the muffler,the spark plugs arent new but are not old either.

[jayrider75]

Hi, I'm back, recently got it running in base mode runs great..as soon as I take it off in order to get it to run is to readjust the distributor , the timing is dead on. I do have a few loose wires ,but I'm sure there from my oil pressure sensor.

[jayrider75]

Hi, realized I had purchased an ecm for a dis system. I have a distributor, it's been looking for a crankshaft sensor. RE installed my original pcm only starts in base, chip doesn't have effect whether it's installed or not. If I purchase the right service number and make sure it's not for dis will it matter if it's manual or automatic? Thanks

[Tech II]

Wow, over two years?

Do you have the original emissions label on the radiator support(sometimes on the strut support)?

It should tell you how to set the timing...... I can't remember that far back, if it was a wire harness that had to be disconnected or if you just jumper A to B in the ALDL connector......in either case, you set the timing(usually 8 degrees BTDC) with a harness disconnected, or the ALDL jumpered......loosen distributor bolt, adjust distributor to timing set on emissions label, and then tighten bolt......then reconnect harness or remove the jumper from the ALDL......now if you look at the timing, it will NOT be the same as the base timing, because now the ECM is controlling the timing....

You must have the correct ECM and PROM for your vehicle.....

[jayrider75]

Yes I can get timing correct, it's the chip that is faulty and I replaced it with another, it'll run good but won't drive, and just the same without a chip, like it'd be on base.

[Tech II]

Have you checked for codes?

Have you looked at data with a scan tool?

Sure you have the correct ECM and PROM numbers? This can easily be checked out at any GM parts department...

[jayrider75]

Yes no codes, I think because it runs with or without chip it's basically on base the whole time. I can't imagine a getting any info for this old pcm from GM. Just ordered one off eBay, same service number and it's silver not black like the last one I bought, which was looking for a ckp sensor, that's why that didn't work.