Cparkes foo Posted October 3, 2017 Report Share Posted October 3, 2017 Hi my car is a 94 3100 gp most of the time it runs great as it has just under 50k but recently it has started reving to 2500 to 3000 rpm, i have replaced iac,tps,map,ats,ecu,plugs wires throttle body gasket,and rubber grommets for pcv, problem has not changed. It has got a 50/50 chance if it runs right or not any suggestions no engine codes plz help Quote Link to comment Share on other sites More sharing options...
Cparkes foo Posted October 3, 2017 Author Report Share Posted October 3, 2017 On a different note ive learned when in nuetral or park i no longer have a rev limiter and at about 4500rpm my doors lock even in park Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted October 3, 2017 Report Share Posted October 3, 2017 Sounds like a wiring issue, to be honest. Ground wires would be the first place I'd check. Quote Link to comment Share on other sites More sharing options...
55trucker Posted October 3, 2017 Report Share Posted October 3, 2017 Try disconnecting the IAC harness AFTER you shut down the engine (shutting off the engine bottoms out the IAC pintle). Leave the harness off the IAC & try to restart the engine, it should not fire seeing as the IAC is closed, if the engine does fire your sucking air in from somewhere else or the IAC is not closed. Pull off your intake snorkel and peek into the throttle body, the blade should be completely closed, if it not then adjust the throttle stop screw so it is just closed all the way but does not bind. Let us know what happens after you're tried these measures. Not setting a code is odd, if the idle is out of range (300 rpm) for more than 50 secs the PCM will set a code. 94 olds vert 1 Quote Link to comment Share on other sites More sharing options...
Cparkes foo Posted October 4, 2017 Author Report Share Posted October 4, 2017 Will try all these things and report back thank you btw clean white grand prixs are sick nice car Quote Link to comment Share on other sites More sharing options...
Cparkes foo Posted October 4, 2017 Author Report Share Posted October 4, 2017 Unplugged iac wont run and throttle body is closed still have to check grounds at a glance they all look fine(no crust) and my engine light has started coming on but no codes, scanner does not registar that its even hooked up so i guess wire chasing is what needs to be done unless there is anyone who has had this and has a fix Quote Link to comment Share on other sites More sharing options...
Cparkes foo Posted October 4, 2017 Author Report Share Posted October 4, 2017 I just tried to do the jumper wire on the obd 1 access point and no flashing codes either Quote Link to comment Share on other sites More sharing options...
Imp558 Posted October 4, 2017 Report Share Posted October 4, 2017 Still sounds like a ground Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted October 4, 2017 Report Share Posted October 4, 2017 I just tried to do the jumper wire on the obd 1 access point and no flashing codes either With a jumper, you ought to at a minimum get the flashing *1 *2 of the check engine light, indicating the ECM is at least operating. Are you positive the ECM is getting 12 volts? Quote Link to comment Share on other sites More sharing options...
55trucker Posted October 4, 2017 Report Share Posted October 4, 2017 The vehicle is a '94, it's OBD1.5, the paperclip/jumper will not function. You're going to find that not every scanner will access the PCM as the necessary software/cable is required. There is another thread on a similar issue with another 94 model. Quote Link to comment Share on other sites More sharing options...
55trucker Posted October 4, 2017 Report Share Posted October 4, 2017 Unplugged iac wont run and throttle body is closed still have to check grounds at a glance they all look fine(no crust) and my engine light has started coming on but no codes, scanner does not registar that its even hooked up so i guess wire chasing is what needs to be done unless there is anyone who has had this and has a fix The PCM has set a code because the IAC was disconnected while the ignition was on, that is normal, seeing as the car is an OBD 1.5 you're going to need a scanner that can read this particular series of electronics. The IAC code should be a DTC-35. Quote Link to comment Share on other sites More sharing options...
Cparkes foo Posted October 5, 2017 Author Report Share Posted October 5, 2017 It goes to our local gm dealer they say they will scan it for me on tuesday i did a little digging on this obd1.5 wow what a nightmare for the diy on a budget guy if i would have known about this i would have hunted a 92 or93 when i was lookin for my car lol Quote Link to comment Share on other sites More sharing options...
Cparkes foo Posted October 5, 2017 Author Report Share Posted October 5, 2017 And thanks for directing me to the other posts they were very helpfull Quote Link to comment Share on other sites More sharing options...
Cparkes foo Posted October 18, 2017 Author Report Share Posted October 18, 2017 So its fixed it was a bad brand new tps talk about bs 94 olds vert 1 Quote Link to comment Share on other sites More sharing options...
94 olds vert Posted October 19, 2017 Report Share Posted October 19, 2017 I should have posted. My L67 in my 2000 GTP had a similar issue when the TPS was going out. After replacing it, that solved the issue. Quote Link to comment Share on other sites More sharing options...
55trucker Posted October 19, 2017 Report Share Posted October 19, 2017 So its fixed it was a bad brand new tps talk about bs Curious: what was the brand of the faulty TPS? Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted October 22, 2017 Report Share Posted October 22, 2017 this does not seem like proof it was the TPS. the problem was there before u put in that one. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted October 23, 2017 Report Share Posted October 23, 2017 If it does it again in a while you may have to do the crank sensor. That's what I was thinking lol Quote Link to comment Share on other sites More sharing options...
wlkstout Posted October 23, 2017 Report Share Posted October 23, 2017 Not sure but does the 94 3.1's have the same issues with the lower intake manifold gasket leaking? Sounds very similar to what my 91 Olds Cutlass Supreme 3.1 was doing before i replaced the LIM gasket. Mine never threw codes either. Did you also look at the EGR? Quote Link to comment Share on other sites More sharing options...
mfewtrail Posted November 1, 2017 Report Share Posted November 1, 2017 this does not seem like proof it was the TPS. the problem was there before u put in that one. He said he was taking it to a dealer, so the TPS diagnosis is probably correct. It's not that uncommon for them to cause rpm surges intermittently when they start to fail. @ Cparkes Foo - The OBD 1.5 thing isn't that big of a deal, there are plenty of old scan tools floating for a reasonable price that will read it. If you need suggestions for one, let me know. Quote Link to comment Share on other sites More sharing options...
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