Nas Escobar Posted January 2, 2014 Report Share Posted January 2, 2014 So I'm having a problem with my 94 Cutlass with the LQ1. Not a major problem, but an issue nonetheless. For the longest time now, this car would hesitate at a cold start, fluctuate the RPM's as it was being heated then normalize itself once the engine reaches normal temperature. Once it reached 200F, everything was perfect... no stumbling, no hesitation, no lack of balls, just LQ1 muscle... and needless to say, this engine can haul ass. Anyways, this random issue has gotten worse with time... maybe it's the recent temperature drop to an average of 30-35 at night and maybe a good 45 max in the day, or maybe it's a bad sensor... regardless, as of late, whenever I cold start this engine, the engine will raise it's RPM to the limit (3500-4000) then drop to 500 and turn off with a strange squeal. I start it again does the same thing, except it will stay on longer and there's no after effects when shutting off. It will do this until 5 or so minutes have passed of consistent on and off motion and then the engine normalizes, the RPM's surge less and don't go past 2000 rpm... or I can take the shortcut and put the car in gear, which will make the RPM's go up to the 3500-4000 range, then stumble onto 500, then raise back up to 1000 and shake very strange. To put things very simple, the exhaust note sounds as if the car was cammed (Which to my knowledge it's not, plus that goes away when the engine is warmed), so it sounds somewhat lopey. There's also a strong smell of raw gas around the car, which has led many people to tell me it's the O2 sensors. Once the engine is warm, nothing... except the SES light turns on SOMETIMES and no one in my area can read the damn thing. Please do us all a favor and save yourself the "get a scanner post" unless you can recommend one to actually use. I've only seen Tech 2 scanners for sale at the parts store so it's not a matter of "oh I'll just go to the store all willy nilly and find one"... nope doesn't work like that here in my area. I wish it did so I don't have to make 100 mile drives for parts, but I digress Another thing noteworthy is that this car will be at the normal RPM when idle in gear BUT if I drop it to neutral while on, the RPM will raise to a steady 2000-2200 and STAY there with no end in sight. The engine will also fluxtuate RPM when cruising. I've cruised at the normal of 2200 at 70mph but also at the high of 3500 with fluxtuations in between 2500 and 3000 inbetween that, with the sweet spot being around 2800 at 65mph. Anyways with that out of the way, where should I start diagnosing this thing? I've already changed the TPS sensor thinking it was that, and it had no effect. I'm suspecting the MAF due to the strong smell of raw gas, and the strange RPM fluxtuations. Can this be an amalgam of many issues gone wrong? I'd love to check the codes on this thing but I can't make a Tech1 scanner pop out of thin air... unless someone in the DC area is willing to lend one. Anyways, all help is appreciated and hopefully someone can help Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted January 2, 2014 Report Share Posted January 2, 2014 MAF or gigantic vacuum leak, probably from intake gaskets. Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 2, 2014 Report Share Posted January 2, 2014 Check all vacuum hoses. Check iac. Check to make sure your injector o-rings arent leaking. A lot of people try to reuse the o-rings even tho theyre like $12 a set. Hope that helps Quote Link to comment Share on other sites More sharing options...
94 olds vert Posted January 2, 2014 Report Share Posted January 2, 2014 MAF or gigantic vacuum leak, probably from intake gaskets. I had similar issues when my MAF was starting to go. Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted January 2, 2014 Author Report Share Posted January 2, 2014 MAF or gigantic vacuum leak, probably from intake gaskets. In the back of my mind... I'm expecting the LIM to be the issue... In reality, I hope is the MAF as I rather do a MAF (which would take 5 mins) instead of a LIM. Check all vacuum hoses. Check iac. Check to make sure your injector o-rings arent leaking. A lot of people try to reuse the o-rings even tho theyre like $12 a set. Hope that helps I've never messed around with this engine before, so the o rings are in the engine or on the tip of the injectors, and how exactly do I go about checking them? Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 2, 2014 Report Share Posted January 2, 2014 Cycle the key a few times to buid up pressure, with the key on look and sniff around the injectors for gas In the back of my mind... I'm expecting the LIM to be the issue... In reality, I hope is the MAF as I rather do a MAF (which would take 5 mins) instead of a LIM. I've never messed around with this engine before, so the o rings are in the engine or on the tip of the injectors, and how exactly do I go about checking them? Quote Link to comment Share on other sites More sharing options...
94 olds vert Posted January 2, 2014 Report Share Posted January 2, 2014 UIM and LIM are easy on the LQ1. I know there is a write up around here somewhere. I did mine on my LQ1. Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 2, 2014 Report Share Posted January 2, 2014 I kno l36 lims are pretty easy too. Guess 3100s are the only ones that are kind of a bitch UIM and LIM are easy on the LQ1. I know there is a write up around here somewhere. I did mine on my LQ1. Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted January 2, 2014 Author Report Share Posted January 2, 2014 I kno l36 lims are pretty easy too. Guess 3100s are the only ones that are kind of a bitch 3400's are too from what I'm told, but I would assume the Camaro's 3800 is a bitch too since they have a quarter of the engine under the firewall. Quote Link to comment Share on other sites More sharing options...
94 olds vert Posted January 2, 2014 Report Share Posted January 2, 2014 http://www.w-body.com/showthread.php/37752-how-to-replace-a-lower-intake-gasket-on-a-3-4-dohc Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted January 3, 2014 Author Report Share Posted January 3, 2014 http://www.w-body.com/showthread.php/37752-how-to-replace-a-lower-intake-gasket-on-a-3-4-dohc Oh wow, so the LIM is actually those brown rubber things?? Very interesting... Before I spend $100 on a MAF, is there any way to make sure that's the area of leakage? Thanks for finding this thread. I shall bookmark this. Quote Link to comment Share on other sites More sharing options...
94 olds vert Posted January 3, 2014 Report Share Posted January 3, 2014 Spray carb cleaner for vacuum leaks and listen for changes in RPM. Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted January 3, 2014 Author Report Share Posted January 3, 2014 So I gotta take the plastic piece that says "3.4 DOHC" off the engine and spray carb cleaner down there? Quote Link to comment Share on other sites More sharing options...
94 olds vert Posted January 3, 2014 Report Share Posted January 3, 2014 Yes, and anywhere else to check vacuum lines. Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted January 3, 2014 Author Report Share Posted January 3, 2014 Welp... looks like I know what I'll be doing once the snow stops. Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted January 3, 2014 Report Share Posted January 3, 2014 (edited) I kno l36 lims are pretty easy too. Guess 3100s are the only ones that are kind of a bitch Negative, just don't strip the rear valve cover bolt. Draining the coolant is the biggest pain and getting a good consistent valley seal. I would highly recommend actual end seals vs just a bead of RTV or Permatex, peace of mind really. Starting fluid works very good as well, which ever has the lowest flashpoint. Don't go crazy with it though, might lose your eyebrows/facial hair. Check out a video on you tube about going about it if your not %100 on it. Edited January 3, 2014 by rich_e777 Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted January 4, 2014 Author Report Share Posted January 4, 2014 (edited) Well I thought I should update but I swapped out my MAF and I'm not sure whether or not to chant victory. Once I first started it, it made the popping noise then cut off. I let it sit, started it again and I sprayed some carb cleaner around the injectors and tried to get into the LIM. Needless to say the exhaust on the car smelled HORRIBLE. I assume I ended up cleaning the inside of the exhaust ports or something because the exhaust just hit you with the smell of carb cleaner. The good news is that it now idles a bit smoother, and now the car idles at 1000 when in park and neutral and SOMETIMES drops below that when in gear and the temperature at normal (200F). I haven't been able to test drive it since it's cold, there's ice outside, and I don't want road salt to hit the frame or body of this car (there is no rust under this car whatsoever) sooo I'm going to wait until most of the ice is gone and the road salt is washed away until I test drive it. I'm also hoping the engine cut itself off the first time because it had more gas in it than needed. I also sprayed carb cleaner around the injectors and tried to get near the lim and it didnt' affect it much when at 200F opposed to when I first started it. I'll try it again once it's warmer and cleaner outside and see what happens. As of now, I'm thinking it may be a vacuum leak and not the LIM as there is some difference with the new MAF. Not too sure though. Below is also the picture of where I sprayed the carb cleaner while it was warming up. It did affect the RPM'S some but not sure if it had much to do with it. I know the cleaner got in the engine for sure though since the exhaust smelled of it. So far still at a loss, but will try again when it's warmer. That's all I can say for now. Edited January 4, 2014 by Nas Escobar Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted January 5, 2014 Author Report Share Posted January 5, 2014 OK, so here's an update. Turns out the carb cleaner is going through the vacuum line in that hole in the picture above... somewhat interesting. I should also add that I drove the car today and it seems to be more responsive but the RPM's keep fluctuating though not as much. A neutral drop still keeps it in 2000 RPM. I still get the stumbling when heating up to 200F that triggers the SES so with all that being said... vacuum leak or LIM? If it's a vacuum leak, where can I get the hoses? Quote Link to comment Share on other sites More sharing options...
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