CLOYES Part # 81018 $191.79 at RA and other has Ductile Iron Cam Gear w/ straight teeth. Straight teeth = more noise in most cases.
Melling # : 2538S (Al cam gear set) still in their catalog
You have to use 84-86 years to find Al gear. Many doesn't list Al gear for 87 & up. 87 & up use DIS so cam and gear gets less load.
"Never checked the vac line to the brake booster, assume i can just block it off?" Yes. Fat Vac line to intake. But Do Not Drive it w/o booster connected. You fight brake and booster forces. Distance to stop is ~1.5 x normal w/ fail/disconnect booster.
I was reading on a search here that the 88 DIS dukes timing is controlled by the ignition module at engine speeds of 400 rpm or less, the ECM kicks in after that, so when the engine is turned by the starter it is the ignition module that controls the timing. Is it possible your new ignition modules are bad or got fried somehow after they were put in?
You didn't answer this one, does the injector have a nice even cone spray pattern?
Also what kind of plugs and at what gap?
did ANYTHING change at all when trying new parts?
Another thing to check, if you can hook up an air compressor to the compression tester hose, pull off the coolent cap, add air and look for bubles in the coolent. I had a bad head gasket once on an 87, close to the same. it would pass a compression test but would bubble air in the coolent, it ran fine but milage droped to 22 vs 30. Also look for water/coolent in the oil. all signs of a bad head gasket.
You didn't answer this one, does the injector have a nice even cone spray pattern?
Also what kind of plugs and at what gap?
did ANYTHING change at all when trying new parts?
Sorry, the injector is brand new and has a nice fan/spray to it. AC-Delco standard plugs & gap It wouldn't run at all until i figured out the PO had put in a new ECM and it had the wrong PROM in it. Now it will sometimes start and half ass run if I manually operate the TB to crack open the blade letting in a little air, but it's sounds like crap. If this was my Formula I would say the timing was way off by how it sounds, coughs sputters and sounds worse the higher it revs. Definitely not right. Because of that i only let it run for a few seconds.
I didn't have time to work on it this weekend, but did have a thought; since it had the wrong PROM in the ECM the whole time i was trying new parts with no change, could the wrong PROM have fried my new ICM?
ECM's in 88 dukes are, for some reason, prone to failure. I went through 3 or 4 of them before finding one that worked good. The one that worked good was from Ebay, originally out of an Olds Cutlass (I think). (I put my Fiero PROM in it.) One of the ones that didn't work was from the Fiero Store, and yes, they gave me a refund on it. One of the bad ones had the strange symptom of not working when it was cold. If you took off the center console and blew a hair dryer on it to warm it up, it worked fine. Not good for winter driving.
Originally posted by TopNotch: ECM's in 88 dukes are, for some reason, prone to failure. I went through 3 or 4 of them before finding one that worked good. The one that worked good was from Ebay, originally out of an Olds Cutlass (I think). (I put my Fiero PROM in it.) One of the ones that didn't work was from the Fiero Store, and yes, they gave me a refund on it. One of the bad ones had the strange symptom of not working when it was cold. If you took off the center console and blew a hair dryer on it to warm it up, it worked fine. Not good for winter driving.
1227748 ECM and others are known for problems. Fiero ECM location doesn't help. Used parts, very likely. 1 problem is GM using coating that would swell and crack solder for surface mounted parts. Good remanufacturer parts should not. A good Reman strips coating on board and reflow solder then recoats the board. Many places just test and if pass slap a sticker then sell as done item.
My other 2 are V-6 and i don't know anybody that has one near me. The contacts to the ECM looked fine. I'm thinking the ICM might have fried from trying to start it with the wrong ECM/PROM. I'm going to swap that out... again ...and check compression and fuel pressure again, this time I'll write it down so when you ask me I'll know.
Well it's got 21,500 miles on it so it did run but i suspect it hasn't run at all for many many years. Again; little old lady owned it and only drove it to church (you know the story), it died and she had the dealer replace the fuel pump, then some time later it died again and she parked it. 2 other people had it afterwards but neither could get it to run and now it's my turn. Part of my problem is undoing what they did trying to fix it.
Good luck, that's tough going in behind someone else who didn't know what they were doing. On the 85 2M4 I bought last year, the young guy I bought it from had started to remove the throttle body and I had to source some missing nuts and bolts and they had also removed the radiator fan and tossed it so I had to find one of those off ebay. Its a fun little driver now.
update; finally had some time and replaced the Ignition Control Module (again) with no change. If anything now it's worse. It will still start if I manually crack open the throttle, still sounds like crap with no power and an occasional skip but now the fuel gauge is pegged (was fine after I dropped the tank) and the tach goes to 1000 when you turn the key off. WTF!!! I'm really starting to dislike this car, I think it's cursed or something. Next step is to recheck compression just to verify it and tell you all what it was (FWIW) and then to hook up the fuel pressure gauge again to see what's happening while she half ass runs.
It might just be me but it looked like the fuel spray was less than last time and I heard a click ------click, click -----click click------click (engine off, key on) coming from between the motor and firewall, not the FP relay but more by the exhaust/starter?? Almost sounded like the plugs were firing but that's impossible...right??? stupid car. I gave myself until the end of July and then I'm giving up. Been almost a year, a LOT of cash with no change all on a freakin 88 Duke! I could have done a complete swap by now. I really wanted to have this one stay original since she's only got 21k on the clock but it's getting time to call the patient and get back to work on my other projects. Sorry, very discouraged and had to vent.
[This message has been edited by DLCLK87GT (edited 06-30-2014).]
Read through your post. My answers may be just issing in the wind, but read, think about them for a second, and answer to yourself maybe or no. Prom normally won't take out ICM but the wrong ECM(distribitor type)can. Incorrect prom can damage ECM. But with too many hands in it, who knows.
Your pulse width on your injector may be thinner now that you are seeing higher temps on the intake air temp sensor.
The clicking. Hmmmm. Broken ECM/harness/ICM ground on one of the bell housing bolts/studs. Would make a lot of sense. Bad grounds throw off things the ECM reads and makes things weak that the ECM controls. (injector, IAC, Ignition bypass) and the grounds help to keep the small signals clean.
Even if the car doesn't start. You can still get codes. Open/shorted sensor readings. Quad driver errors. Prom error will post code without start. And should always at least post a 12 code unless you have a wiring/harness problem or bad ECM.
When you pulled the crank sensor out with the module, was there trash/rust fillings on the end of the magnet? If so pull it back out, put a strong magnet probe in the sensor hole and turn it over by hand to clean the trash off the crank.
Originally posted by cmechmann: When you pulled the crank sensor out with the module, was there trash/rust fillings on the end of the magnet? If so pull it back out, put a strong magnet probe in the sensor hole and turn it over by hand to clean the trash off the crank.
No it was clean as a whistle. And the ECM and new PROM were put in at the same time. Then a second new ICM. I also ran a new ground from the ICM to the body. One thing to add is the engine harness isn't attached as it should be everywhere. It's obviously been tinkered with in the past 10 years of going from owner to owner and not running, so one last step may be to pull the harness and go over it end to end. Pull the plastic loom and tape off and see what it looks like underneath. I'm no master mechanic but assume a shorted wire should stand out like a ...well... a shorted wire. I'll check for codes but assumed with the new ECM there would be no codes to read. Edit to add; I cut the rubber hose connecting the brake vacuum line and put my finger over the pipe coming off the intake; no change...but after about 10 seconds of running it did try to suck my finger into the tube...kinda hurt too. FYI the hose looked bad and needed to be replaced so no harm in cutting it to block it off.
[This message has been edited by DLCLK87GT (edited 06-30-2014).]
I have a 3000GT and it had issues with warm starts. It wouldn't start, or when it got running it sounded like total crap and would just barely run. It turned out to be a bad coolant temperature sensor. I don't know if the 88s have a similar circuit but in my case, the coolant sensor was telling it the engine was the wrong temp and it was flooding with fuel. Just a thought... I also may still have an ECM off an 88 if you want to try a different one. I used to have a throttle body too, but I believe I sold it at some point. I can check the garage though.
I'm no master mechanic but assume a shorted wire should stand out like a ...well... a shorted wire.
Not necessarily. I have had multiple cars where the wire broken internally but the jacket was still in place and good. Eyeballing would have not helped. I just replaced a bad ABS wire on an Aztek, and had one of the coil wires on a 2.8 with the same issue- but the wire inside was bad.
You shouldn't need to go into the loom far unless someone has really hacked up the harness. But it would help to follow the grounds back to where they group together to make sure they haven't broken there Normally they will break right on the end where the eye terminal is right near where they are supposed to be bolted to. Most of the Gms I've worked on will be on the trans to engine bolts on an automatic fwd. On 2.5 could be on a head bolt. There should be several 2 or more from the ECM. Then one different color for the O2 ground. Another for map and tps. The ignition bolts to the engine, but sometimes will have a ground to clean up the crank signal. All this can also be for nothing if you have a bad ground between the engine and body. That is normally a strap or heavy cable. Small signal wires like distributor pickups, Abs wheel sensors and Speed sensors can break inside the shielding where they are moved/stressed.
[This message has been edited by cmechmann (edited 06-30-2014).]
Helped a fellow worker at the shop 2 days ago. I helped him, but made him do the repairs. He learned a lot and a lot better understanding of what has to work. 1989 S10 2.5 with distributor. Hard start. Stall if you just touched the gas. Loping idle. Ended up with. Remove after market tack(hooked up wrong, should have been on the white wire from the module). Replaced missing coolant sensor(had a after market sending unit where the sensor was supposed to be). Put the oil sending unit back. Repaired 2 grounds. Pulled the fuse box to remove the bulk connector on the fire wall to repair bad connection from battery to fuse box(wouldn't post codes, no code 12). Replaced Tps( would go open just off idle). He drove it home. Didn't use the scanner until finding the bad TPS. He also has a bad VSS reading due to a broken speedo cable. If you don't have one, get a volt meter. even a cheap one will do.
How about pulling out the new spark plugs and making sure they're not wet, soaked with fuel from all of the cranking. If so, spray em with brake clean and blow em dry. Then...
Bend a paperclip and jamb it into the end of one of the spark plug wires. Have a friend crank it over while you hold the paperclip close to a ground 1/8" away. If you have a strong spark...car should run.
How about pulling out the new spark plugs and making sure they're not wet, soaked with fuel from all of the cranking. If so, spray em with brake clean and blow em dry. Then...
Bend a paperclip and jamb it into the end of one of the spark plug wires. Have a friend crank it over while you hold the paperclip close to a ground 1/8" away. If you have a strong spark...car should run.
The car will run, just not by itself. I checked each wire with a timing light pickup and they all fire. I will check the plugs when I recheck compression, probably this weekend as well as fuel pressure, but I think it’s an electrical issue due to the tach and fuel gauge now not working right. One thing i was going to do but didn't...run the car at night with all the light off. When it stumbles I’ll bet there’s something shorting out causing a spark.
FYI the hose looked bad and needed to be replaced so no harm in cutting it to block it off.
