Hello. Trying to get our new find; a low mileage, 88 2.5 AT up and running before winter sets in. Got it in September with a dead fuel pump and had to replace the tank due to rust, brand new pump, recalibrated fuel level sender, new plugs & wires, oil, filters and a rebuilt throttle wheel thing. When I try to start it, she’ll fire up but only run briefly and not very well. Sounds like it’s way below idle and if I give it gas it’ll immediately die. Looking in the TB while it’s running, the injector is dumping in fuel. It’s not a nice even spay, more like a garden hose. If I open the throttle blade, I see a puddle of gas on the bottom of the intake. I think it's flooding itself out but ??This is my first 2.5 so I’m not familiar with it so any suggestions would be great. Oh, somebody mentioned to check the ICM and make sure there’s a plate under it because if it’s missing it will cause issues. Is this true? What does it look like and what do I do if it’s missing?
Read rest of cave, 4 cyl engine section and others as needed.
If TBI has bad oring on injector, can leak gas. Apply power to ALDL pin G to turn on fuel pump an look at TBI... Leaking should be easy to see.
Check fuel pressure too.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Originally posted by theogre: If TBI has bad oring on injector, can leak gas. Apply power to ALDL pin G to turn on fuel pump an look at TBI... Leaking should be easy to see.
Ok, will do but what's the difference betweeen this and just turning on the key? I'm guessing that by doing this it keeps the pump on until i remove power, where key on only turns it on briefly?? Edit to add; in your cave you mention "There are test ("noid") lights for the injector used in the 700. Use them! " what exactly is an injector noid light?
[This message has been edited by DLCLK87GT (edited 11-26-2013).]
A noid light is used to determine if you are receiving injector pulses at the injector. It would be used to troubleshoot a no-start condition. You would unplug the wire from the injector and plug it onto the noid light and crank the engine. If the light lights then you know the injector is both receiving power and the pulses from the ECM.
However since your car starts, assuming the fuel isn't just leaking out all the time that would indicate you have power and the ECM is pulsing the injector. So a noid light isn't much use for this trouble.
If you aren't sure if the injector is just leaking fuel into the throttle body or being pulsed you could alternatively try this. Just unplug the injector and crank the engine. If the fuel is no longer being dumped into the throttle body that would indicate the fuel is being metered by the injector and not just leaking in.
There is also a potential problem that the injector is opening but closing slowly.
[This message has been edited by phonedawgz (edited 11-26-2013).]
Ok cool. Assuming it's not a complete downpour I'll try this when i get home. The PO told me he replaced the ICM and injector in an attemp to get it running and i have no reason to believe he didn't. I do have reason to believe he may have screwed something up while throwing parts at it though.
[This message has been edited by DLCLK87GT (edited 11-26-2013).]
Originally posted by phonedawgz: If you aren't sure if the injector is just leaking fuel into the throttle body or being pulsed you could alternatively try this. Just unplug the injector and crank the engine. If the fuel is no longer being dumped into the throttle body that would indicate the fuel is being metered by the injector and not just leaking in. There is also a potential problem that the injector is opening but closing slowly.
So I was able to check a few things out; I unplugged the injector and cranked it over, there was no fuel leaking from it. FWIW - As best as I can tell the PIM shield is in place. I applied power to the ALDL - G terminal and nothing, no click- no pump noise- nuttin. If I turn the key I hear both, but not this way. What does this mean?
[This message has been edited by DLCLK87GT (edited 11-29-2013).]
Anybody? Hate to keep asking but I've searched and searched, been to the cave.... I know the 2.8 and all the things to check but this 2.5 has me stumped. I'd rather not just throw parts at it like the PO did and figure out what's really wrong with it first.
Based on it dumping fuel like a garden hose when cranking over, it sounds like it's a bad injector. I say this simply because I've never seen flow like that in any injector, other than bad ones, regardless of the signal they're receiving...others may disagree. You say it was replaced. Maybe it was, or maybe the replacement was bad. But before you run out and throw money at it, see what others say...
Originally posted by Neils88: it sounds like it's a bad injector. ...
I was thinking along the same lines....the injector may be the issue. eBay has new ones for $30 so I may just order one anyway. Tomorrow I'll pull it out and see if its clogged up or something, Its a possibility seeing how crapped up the tank was. After that I'll probably just pull and rebuild the whole TB. It's ben sitting for ??? so it should be done anyway. ...stupid car
[This message has been edited by DLCLK87GT (edited 11-29-2013).]
I was thinking along the same lines....the injector may be the issue. eBay has new ones for $30 so I may just order one anyway. Tomorrow I'll pull it out and see if its clogged up or something, Its a possibility seeing how crapped up the tank was. After that I'll probably just pull and rebuild the whole TB. It's ben sitting for ??? so it should be done anyway. ...stupid car
If you were closer, I'd tell you just to come grab my TB. '88 2.5 just sitting in the garage with nothing to do... Shipping probably wouldn't make it worth while.
EDIT: My 2.5 was sitting for 10 years, but ran perfectly after I changed the fuel pump and filter.
[This message has been edited by Neils88 (edited 11-29-2013).]
Originally posted by Neils88: If you were closer, I'd tell you just to come grab my TB. '88 2.5 just sitting in the garage with nothing to do...
if I was I might just do that....even thought about getting one from the local u-pull it yard. But this car has less that 22k on it so once I figure out the electrical/fuel issue I should be golden. Still curious why applying power to the ALDL-G pin didn't power up the fuel pump, that has to mean something.
Originally posted by DLCLK87GT: if I was I might just do that....even thought about getting one from the local u-pull it yard. But this car has less that 22k on it so once I figure out the electrical/fuel issue I should be golden. Still curious why applying power to the ALDL-G pin didn't power up the fuel pump, that has to mean something.
Make sure is G... See my Cave, ALDL/ALCL If you got that wrong... Can do ECM damage.
Power to G bypass all relays/switches and fuse(s). Power to G means FP is On. FP is On then any leak will show, including bad O rings on injector.
700 injector is very reliable. ECM ground the injector to add fuel to engine. Iffy ECM or wire between ECM and injector w/ a short can dump fuel.
Check fuel pressure... High pressure means regulator or return line problems. High pressure can hurt/kill the FP. Good flow is coolant fuel for the pump.
Make sure is G... Power to G bypass all relays/switches and fuse(s). Power to G means FP is On. FP is On then any leak will show, including bad O rings on injector.
I did this, took power from the ciggy lighter and applied to G with a test light. The light lit and it was definitely the G pin but nothing happened. No relay click no fuel pump whine, nothing. Key on and I can hear both but not this way...why?
quote
Originally posted by theogre: 700 injector is very reliable. ECM ground the injector to add fuel to engine. Iffy ECM or wire between ECM and injector w/ a short can dump fuel.
I looked over the wires and everything looks fine. I did however notice several things are not attached to the chassis; the twin relays by the air cleaner are unscrewed from the firewall, so are the two large connectors by the battery. They're all hooked up like they should be but are not screwed to the car. Why?.... No idea.... but will this matter?
[This message has been edited by DLCLK87GT (edited 11-30-2013).]
Use the ALDL "key." ALDL can be mounted Key up or down.
Pin A is ALDL Ground and will turn on a test light. If 12v goes to Pin M then it can turn on a test bulb and do damage to ECM. Pin M is 1227748 ECM Data Out.
Light bulb in series w/ pump may not work. Again make sure is G and use wire only to 12v.
Yes, as before I know it was the G pin, even dbl checked that the ALDL was mounted properly. Applied power to G, upper pin, closest to the ciggy lighter. Put power to this and nothing. not sure what that means so I don't know what to do... but just for the hell of it I pulled the plugs, checked each was gapped properly and seated, torked properly, put new wires on, triple checked the connection to the coils and ....the battery was dead.. LOL damn car.... it's on a charger now and will retry in the morning. Might head off to the local u-pull it for a replacement coil brick. Not sure something is wrong with mine but at the least I can pull one off a junk car to see what it's all about and then investigate mine. I'll tell them its for an S-10 and hopefully it'll only cost me $20. Mention Fiero..**** that's getting hard to find, that'll be $80
edit to add the battery sucks and has nothing to do with this cars issues. ...FWIW ...damn car
[This message has been edited by DLCLK87GT (edited 11-30-2013).]
Originally posted by theogre: Light bulb in series w/ pump may not work. Again make sure is G and use wire only to 12v.
Ogre, you are 100% correct. This time I used a piece of 12 gauge wire and the pump came on which is good...and no leaking at the injector which is also good but the damn battery is dead so I'm off to Wal-Mart to exchange it for a good one.
UPDATE; I finally got a new battery but that wasn't the issue and there probably wasn't anything wrong with it in the first place. But regardless a new-fresh battery installed and now it wont do anything. I hear the pump come on, if I hold the pump relay I can feel it click but the car (motor) is otherwise dead. At least before it ran...yes like total crap but now nothing. All I did was replace the wires, rechecked the plugs, looked over the wires in the engine compartment and use a heavy gauge wire to jump the ALDL G pin to check the injector for leakage. And no I didn't apply power to any other pin, just G. I'm going in reverse here and getting discouraged...I think this car doesn't like me. Suggestions other than sell it LOL? I found a good deal on the coil brick (2 coils AND the ICM under it) is replacing that the next step?
[This message has been edited by DLCLK87GT (edited 12-03-2013).]
ICM sounds like the problem. Probably ran bad because it was overheating and finally died..
this will cause the engine to be completly dead? I'd think it would at least turn over. This is acting like a dead battery and nothing happens.
quote
Originally posted by gtxbullet: if you got a good deal on the whole bundle do it.
I can get a new ICM and 2 coils for under $60 but no warranty. AutoZone/Advance Auto has the ICM for $88 and coils for $40 each. 4x the price but they offer a lifetime warranty.
It won't crank over? If so, the ICM won't cause that issue.
Didn't think so. It did before i hot wired the fuel pump ALDL G-pin to check the injector, even ran for a few seconds. After that nothing.
quote
Originally posted by jaskispyder: Check battery cables to the starter and to the ground? Starter good? fusible links?
starter worked before. I went over the harnes to check for bad wires, didn't find any and the engine ground strap was good too. Guess i better check over the wires again. What fuseable link should i be checking and how do i ?
Finally had time to work on this...replaced the battery and cables, checked the grounds, fuses and connections, all good...but still turn the key and nothing. I get the click and fuel pump run but nothing else, wont even turn over. I opened up the large connector next to the battery and inside it's disgusting. Assume it to be 25 year old dielectric grease that's changed into a thick black tar. Not sure if this has anything to do with it being dead but is there a way to clean this connection? Next step is to check/replace the fusible links. Will have to search that one, not great with car electrical systems past the basics.
As a mechanic that does diagnostic testing - once you get it to crank if the overfueling issue continues I would suspect the map sensor or the coolant temp sensor, if either of them are bad or way out of range they can cause the ecm to thnik it needs to add more fuel than is needed. The coolant temp sensor could be telling the ecm that is is -40 degres and the ecm will open the injector up when cranking.
I opened up the large connector next to the battery and inside it's disgusting. Assume it to be 25 year old dielectric grease that's changed into a thick black tar.
That's the way it is supposed to be. Do not clean that stuff off. Look for discoloration on the fusable links. Have you cleaned and tightened the starter connection?
Originally posted by Gall757: That's the way it is supposed to be. Do not clean that stuff off. Look for discoloration on the fusable links. Have you cleaned and tightened the starter connection?
I looked at the starter, the wire and the links and they all looks fine. I got a new positive cable that I will replace later this week, time & weather permitting. My issue is; it cranked over, even started and ran for a bit after replacing the tank and pump. That was what I was working on fixing, the piss poor running. It ran like crap, but it ran. I posted on here and was told to check the injector buy jumping the ALDL. I did that, there was no leakage at the injector but then after that the car was dead. when I did this i know i had the right pin on the ALDL, i didn't "spark" anything but either what I did or coincidently the car died and I don't understand why. It's very frustrating ....
After a little detective work (thanks Redlineplus) it turned out to be the starter, it was stuck. I checked for power at it and I had power but it didn't do anything...until I hit it with a hammer! Then it started working again but I replaced it anyway. Now with a new starter I'm back to where I was; It starts, runs for a few seconds, sounds like crap and then dies. This time it did sound like it was revving, or trying to before it died. I accused my helper of pumping the gas but she didn't, it was doing it by itself. What's should I check next? Edit to say, is there something else I should check, clean, inspect before i replace the ICM, coils and crank sensor? Don't want to spend $200 if that's not the problem. If it is OK but if I do and nothing changes...well you get the point.
[This message has been edited by DLCLK87GT (edited 12-28-2013).]
Anyone? This morning I went out and hooked up a timing light to each plug wire and it lit on each wire while cranking so I know the coils are working....or I assume they are. Does this mean that the ICM is bad or do I need to clean and adjust the IAC.....possibly a bad FPR?? I really need some help before I just start throwing parts at this. I'd rather know the issue and fix it than to start replacing things one at a time.
No codes? If I knew more about the 88 Duke I would suggest something. A disconnected vacuum tube will make an engine do what you are describing...(best I can do.. )
No codes? If I knew more about the 88 Duke I would suggest something. A disconnected vacuum tube will make an engine do what you are describing...(best I can do.. )
the car hasn't been run in forever and I can't get it to run long enough to generate codes, best is 5 - 10 seconds before it dies. vacuum lines look good best I can tell.
If you can make it run longer by spraying starting fluid in the throttle body, you would at least know that there is a fuel delivery problem. If nothing is different, you have a spark problem.
If you can make it run longer by spraying starting fluid in the throttle body, you would at least know that there is a fuel delivery problem. If nothing is different, you have a spark problem.
Fuel delivery isn't an issue, actually I thought just the opposite; too much fuel being dumped by the injector. But I've read that the Dukes TB can look like it's pouring fuel out the injector to those not familiar with the TB on the 2.5. Since I'm not getting much help here I went and got a new ICM and crank position sensor which I'm about to go change. wish me good luck!
I just replaced the ICM and the Crank positioning sensor and .....now it wont start at all. It just cranks over and over, makes a PUFF and nothing. At least before it ran for a few seconds.........I'm making things worse. Before I put this on CL can somebody please help me???????
Ok...you've confirmed you have fuel, and you have spark...but no start. Sounds like a timing issue. Maybe the new crank position sensor or ICM were bad? Are the plug wires on the right plugs? Scratching my head...
Been following this thread for a bit and I feel for you. I have an 88 2M4 as well. Had some [engine] problems that lasted 6 or so months but finally got it straightened out. So there is hope. Do you have a GM service manual? Helped me out a great deal. If not, PM me and let me know. I can email you my DropBox link for the down load.
I don't know...after I was done and it wouldn't start I slammed the lid shut and walked away. I'll give it a day or two to think about what it did...or didn't do, and then recheck my work. Hopefully I just crossed the plug wires, unplugged something by accident or something stupid like that. Hopefully. For a car with less than 22k miles, this is acting very odd. Dead/bad fuel pump from sitting I can see, but all these other issues just don't make sense. I swear the car doesn't like me. LOL...if that's possible.
After letting it "think about it" I rechecked things and I had a plug wire in the wrong spot After putting them in the correct locations it started but not much better than before. I then replace the 2 coils hoping one was bad and causing the chug chug chug running issue but nope, still a no go. I can start it, it "diesels" but before I can go from the drivers seat back to the engine it dies. If I pump the gas it now will run instead of instantly dyeing but it' sounds horrible, like the timing is way off. Is this possible with a 88 2.5 DIS? I thought the timing was all done electronically?? And it's all new so I'm stumped. And to recap, I've replaced; Fuel pump as it was supposed to be the issue from day 1 ... & gas tank, plugs, wires, battery, Negative cable, starter, crank positioning sensor, ignition control module, both coils and probably a few other items. I've checked the wires and ground, all look good. Fusible links near the battery also look good. I'm not sure what my next step is other than pulling the TB and rebuilding that...or selling it. I hate to keep throwing money at it not knowing what's wrong but ...?? Edit to say that is it possible it's the Engine Control Module? Is there a way to test these? I could go get one from the pick-n-pull but I have no way to know if it's bad too. again, thanks for any help....this is SO frustrating.
[This message has been edited by DLCLK87GT (edited 01-05-2014).]
If you can make it run longer by spraying starting fluid in the throttle body, you would at least know that there is a fuel delivery problem. If nothing is different, you have a spark problem.
)
After putting them in the correct locations it started but not much better than before. I then replace the 2 coils hoping one was bad and causing the chug chug chug running issue but nope, still a no go. I can start it, it "diesels" but before I can go from the drivers seat back to the engine it dies. If I pump the gas it now will run instead of instantly dyeing but it' sounds horrible, like the timing is way off. Is this possible with a 88 2.5 DIS? I thought the timing was all done electronically?? And it's all new so I'm stumped. 
