When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My cruise doesn't work either. Does vac come from here to?
I was going to try to trace back from the cruise control.
keep going you will find it.
i believe that the cruise is held with vacum. so...if you have no vacum....then cruise probably won't hold.
just a theory i do not know if that is correct. is it possible that the cruise control vac unit (should be by your battery) can be a source of a leak? the op asked this but i dont think its been answered.
I remember several threads where it ran better with the maf off...it means something, can't remember, you may be able to find it with some searches.unless one of the wiz's here chips in......start another thread with "runs better with MAF off"...you'll get an answer....think it was something about the o2 sensor.....good luck
Waiting for my aldl cable so I thought I'd check my tps. Interesting results. I have been setting it at .54 after idle adjustments. So today I check the voltage and as I slowly open it to wot. Dead spots!! Now that can't be good.
Thx Viking
I see one for a jimmy on whitetailsheds profile, I'm looking for the last pic you sent me. I'd buy that one cuz it says for Vette and my year. 1988. Think he just had one?
I'll pm you my email if you can share the direct link
A friend of mine who worked as a gm mechanic took it for a drive and says there is no way its stock, someone had been in the engine he says. So idk what has been done. I've only had the car since October and had it out five times since I bought it. Cold Canadian winters...
Ok thought I had it licked today. I bought a new iac, cleaned the tb up really good put it together, set it using procedure for idle and tps . Was working great. Then I get an error 33 code. I check it out as its a maf code, then realize I had not plugged it in. I plug it in and bang I'm back at idle of 13-14 again. With it unplugged I get 700. What's going on? No code plugged in yet idle is super high, unplugged it idles nice and low.
I think it is a vac leak I had numerous leaks and it was like peeling an onion. I followed the vac diagram replaced every hose as I went. Some hoses were even misrouted. It is a very simple dia to follow.
Hi,
I don't have the shop Manuel yet. Is there a simple way to plug the lines say coming off intake and go with process of elimination?
The tb was plugged where you can adjust the idle so no one has played with that. I did pull the tb idle screw to bring it down and adjusted tps to new settings. I know this isn't a fix, but was temp to drive it.
Can't wait for my cable to arrive this week and hook it to a laptop
Quit screwing with the screw. Make sure the TB is clean first. That means taking it off and cleaning the TB, remove IAC and the housing and cleaning that and new gaskets.
Lol aklim I will quit screwing with the screw..
I've had the tb off a few times to clean, plus there is a new iac in there now . Waiting on the cable, it's showing cleared through customs so any day now to get it.
Then I'll have to learn procedure to hook it up. I have the two windows based programs downloaded already.
I had to mess with the screw otherwise it would idle up to 2000 rpm basically cruise on the hwy. a vacuum leak this big would surly show performance loss, or a low vac reading ???
Like I said before I bought it in October and drove it home and it did this. So existing problem. Since having it, I've done LT headers and 3.54 gears.
Breaks tires loose at 60 km/h by punching it. So the torque is still there.
I've had the tb off a few times to clean, plus there is a new iac in there now .
I had to mess with the screw
Yes. Until you get a scanner, you are screwing with the screw
But did you remove the IAC housing and clean that too? It can be dirty. If you did, make sure there is a fresh gasket since it too can leak.
What you will want to do is get it to closed loop. If that doesn't work, you cannot adjust it. Shut everything off but the engine. See what the thing is doing for IAC counts. Ideally you want about 30 counts. So if you get 60 counts, the IAC is opening up too much. So screw the screw in a bit, rev and retry. If it goes lower, how much lower? If not at target, screw it in and rev and re read. If it is too low, screw the screw out.
Screwing it in opens up the butterflies and out closes it. If the IAC is opening more than target, it means that the ECM wants more air so it opens the IAC. Give it more air via the butterflies and it will demand less via the IAC. The reverse is true
I'm going to make a guess here before my cable comes...
That my coolant temp sensor isn't working causing it to stay in open loop.
Is that a possible hypothesis??
I'm going to make a guess here before my cable comes...
That my coolant temp sensor isn't working causing it to stay in open loop.
Is that a possible hypothesis??
Possible. Could be that but without the scanner, all we do is throw parts at it. You need the scanner so you can see what the ECM is seeing. A VERY ROUGH way to tell is to check the gauge vs the ECM reading. A better way is to have an infra red thermometer to scan the CTS and see what it should be seeing vs the ECM reports. Don't throw parts till you know
Ok I got the cable today!
So my iac counts were 15, and it did go into closed loop, I adjusted the idle screw out to get 29 iac counts . I'm new to this programming. Lol noticed flags of rich . What should I look for as per Maf and O2 ?
Ok I got the cable today!
So my iac counts were 15, and it did go into closed loop, I adjusted the idle screw out to get 29 iac counts . I'm new to this programming. Lol noticed flags of rich . What should I look for as per Maf and O2 ?
OK. Did it hold steady at 29 after revving the engine? If so, that is what you want. Can I assume the timing is right? What about the TPS voltage? Coolant?
04-16-2015, 12:36 AM
