rossg Posted August 1, 2008 Report Share Posted August 1, 2008 I have a 94 cutlass with a 3.4 78,000 miles. Here is the problem I have sometimes the car will cranck for a long time then start. it seems to start better if I put my foot to the floor when I start it. I know doing this will put the car into anti flood mode (turns off the fuel) This does not happen all the time. However there is no indication that it is going to happen it just does. Now second problem is poor mileage i only seem to be getting 15mpg I am not hard on the gas and I used to get 25 out off my 94 gtp with a 3.4. I am not getting any codes other than a code 55 witch is a transmission code. My snap on scanner shows me all the vehicle perameters but i don't see anything amiss. Could it be in my fuel pressure regulator if so where is it? I think the car is dumping fuel when shut off but I don't think it is in the injectors. So if anyone knows anything about this type of problem let me know. Thanks Quote Link to comment Share on other sites More sharing options...
Fleeingpepper Posted August 1, 2008 Report Share Posted August 1, 2008 Well the gas mileage.. I get piss poor mileage in my vert too. They're heavy vehicles. IIRC around 4,000 pounds. Quote Link to comment Share on other sites More sharing options...
jmoore4294 Posted August 1, 2008 Report Share Posted August 1, 2008 Well....HOLY SHIT RESIZE YOUR SIG PIC!! Seriously though, I usually get about 15 mpg. I don't know how you got 25 really. City or highway? Brand new they were only rated 16 or 17 city IIRC. Quote Link to comment Share on other sites More sharing options...
spiderw31 Posted August 1, 2008 Report Share Posted August 1, 2008 IF the car actually is dumping fuel into the cylinders after being shut off, then you'd be looking at a bad injector. That is the only place fuel would come from. Could it fail to to high pressure as a result of a failing FPR? Dunno, but I guess it could be possible. Get a fuel pressure test gage, and hook it up to the schrader valve (under the little cap on the fuel line near the fuel rail, looks like the valve on a tire after you pull the cap). Turn the key to the on position but don't start the car. You should hear the fuel pump run for a few seconds and then stop. Now turn the key off and check the pressure. It should be somewhere areound 40-45psi, and it shouldn't drop more than a few psi over 20-30 minutes. And yeah, resize that pic before "they" come and do it for you! Quote Link to comment Share on other sites More sharing options...
old442man Posted August 1, 2008 Report Share Posted August 1, 2008 I'm on my second fuel pressure regulator. Does it do this more cold or hot? If it does it cold I would definetly say FPR but if it does it like at a stoplight I would say Mass airflow sensor. A buddy had a 3.4 cutlass with the same problem. As I was typing this there I had a GM mechanic walk into my store and he said he thinks that the FPR is in that valley in between your cams or it's behind the plenum. I would suggest finding a picture online because the one for your car is not easy to spot. Oh and the gas mileage my coupe was getting 22-24 then I started using non-oxygenated non-ethanol 91 octane, here it costs more but my car runs a lot better and I'm getting 26-28 everytime. Quote Link to comment Share on other sites More sharing options...
rossg Posted August 1, 2008 Author Report Share Posted August 1, 2008 yeah plan is to get a fuel pressure tester on the car. I do get a maf code but it is a history code so I don't know if thats the problem it doesn't light the mil. It is only a history code and can be erased easily. I don't know if it came back as I havn't put the car on the scanner in a couple days. Quote Link to comment Share on other sites More sharing options...
rossg Posted August 1, 2008 Author Report Share Posted August 1, 2008 it does it more often on cold starts seems to be ok when i am going on short runs but it does happen sometimes when its warmed up. I did use super in my grand prix the car was pretty good on gas. I have been reserching and the car should get about 22-25 mpg from what I've seen. I think the fpr is under the plenum not my first trip under there on 1 of these but I was trying to avoid it. I'm on my second fuel pressure regulator. Does it do this more cold or hot? If it does it cold I would definetly say FPR but if it does it like at a stoplight I would say Mass airflow sensor. A buddy had a 3.4 cutlass with the same problem. As I was typing this there I had a GM mechanic walk into my store and he said he thinks that the FPR is in that valley in between your cams or it's behind the plenum. I would suggest finding a picture online because the one for your car is not easy to spot. Oh and the gas mileage my coupe was getting 22-24 then I started using non-oxygenated non-ethanol 91 octane, here it costs more but my car runs a lot better and I'm getting 26-28 everytime. Quote Link to comment Share on other sites More sharing options...
old442man Posted August 2, 2008 Report Share Posted August 2, 2008 Well if you think it might be your maf sensor you could try this stuff it's made by CRC and it's MAF sensor cleaner it's only 8-9 bucks the part # is 05110. I haven't had any reviews but I would say it's worth a shot. Unfortunately I don't know of any cure-in-a-can for your fpr but I think it sounds like that is your problem. it's been 5 years since I replaced my maf but I distinctly remember my car dying when I would try to race off of a stoplight but not too much hassle at cold starts. I got a used one and it has worked just fine. Either way I'm curious to know what you find out. Quote Link to comment Share on other sites More sharing options...
Fleeingpepper Posted August 2, 2008 Report Share Posted August 2, 2008 http://www.w-body.com/forum/index.php?topic=67815.0 EPA said 17/29 for verts. Quote Link to comment Share on other sites More sharing options...
rossg Posted August 3, 2008 Author Report Share Posted August 3, 2008 http://www.w-body.com/forum/index.php?topic=67815.0 EPA said 17/29 for verts. I am getting 15 highway Quote Link to comment Share on other sites More sharing options...
rossg Posted August 3, 2008 Author Report Share Posted August 3, 2008 I think it may be the maf i took it out and cleaned it now it is dropping maf codes. the 1 that is in is a reman but lord only knows how long its been in there. I am going to pick up a new maf and try that. Quote Link to comment Share on other sites More sharing options...
rossg Posted September 21, 2008 Author Report Share Posted September 21, 2008 it wound up being a bad fuel pressure regulator. Now I have a new problem the idle surges when you start the car cold after it has been run it starts no problem. Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted September 22, 2008 Report Share Posted September 22, 2008 Vacuum leak? Quote Link to comment Share on other sites More sharing options...
jake91 Posted October 3, 2008 Report Share Posted October 3, 2008 not sure about your mileage but when i bought mine the timing was off and it started hard Quote Link to comment Share on other sites More sharing options...
rossg Posted October 5, 2008 Author Report Share Posted October 5, 2008 Vacuum leak? yes it was a vacum leak from the intake manifold gasket. i did a right up on it check it out Quote Link to comment Share on other sites More sharing options...
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