L98: starts, but won't keep running.

The shop manual (Section 6E) and a pressure gauge will save you time and a bundle of dollars throwing parts at an unknown problem. Without codes though even that won't be easy.

Gentle throttle tends to rule out an idle air circuit failing to open.

Since you know spark is OK then its time to figure out what's happening first. Is the fuel pump shutting down or the injectors all shutting off with plenty of pressure on the rail.

If the engine runs for 2 seconds and then dies of fuel starvation, it could be failure of the ECM to receive a pulse train from the distributor --that will shut down the injectors. I've seen that in a

You might also pull the vacuum line on the fuel pressure regulator and see if there's gasoline leaking from the wet side to the vacuum side.

Best to get out the book.

PJ

This sounds just like what happened to my 86. It turned out to be a bad fuel pump. Once replaced the car ran as well as it ever has.

Fuel filter?

Hi All:

Thanks for all the replies and tips, certainly appreciated. One thing puzzles me, don't these cars throw a code if the fuel pressure is low? It seems that this is elementry for a FI system to function properly and with all the other things that the system seems to monitor it seems odd to leave this out.

You mean like the code that the 72,000 pounds of computers that monitor the space shuttle said "you have a deadly hole in your wing"? Shit happens or should I say it don't happen when it needs to, plus you're dealing with and older, less sophisticated computer system. You still need to do as you were doing, is there spark, is there fuel, is the exhaust restricted, and so on and check the basics before you start looking for an exotic problem. I'd be glad to post the fuel management codes definition if you can retrieve it. There are about 400 trouble codes today that can be displayed and I've had a complete computer failure in a C5 that threw no code pertaining to it's demise. By the way, in that case it would start but would not move more that a few inches before shutting down. The good thing was it would run and allow us to keep the air-conditioning running on a very hot expressway while waiting on the flatbed.

Gee, that sounds like a fun car for $45,000 or more.

Hi again:

Dad, if you can post the code definitions I would be curious to see them, I have a small reader and booklet that lists some that are tied to 'blinks' that give you some information but I don't think it is as comprehensive as what you are talking about. Perhaps you could send them as an attachment to me via e-mail of perhaps an FTP? As to the fuel pressure on these cars, monitoring that would be as simple as the oil pressure light on a 56 Buick, just turn it on if pressure falls below a certain value.

I just put a fuel filter on the car, it made no difference. After experimenting some I am able to keep the car running, (sort of) by careful throttle positioning so that lets out oil pressure switch problems or a distributer not telling the ECM to continue spark. Looking at the plugs it is obvious that the car is running EXTREMELY lean, IMHO lean enough where engine damage could result from trying to run it, which should be throwing a code too. Since this is not the case I am beginning to think the ECM is getting a spurious signal from some sensor that monitors the exhaust gas makup, or the ECM itself is not functioning properly. As near as I can tell, there are no exhaust restrictions. There seem to be some setups that let you hook up a laptop to the ECM and, along with some software, see what the ECM 'thinks' is going on. Has anyone here used these setups on the L98 engines, and does anyone have an idea as to the pros and cons of the various setups? It seems like this would be a very valuable diagnostic and tuning tool.

TIA Dave G.

Actual sticker price was less than 40k, where have you been? What I paid was less than that, but then I'm sure you have a fun car for much less.

"Dave Gee" wrote in message news: snipped-for-privacy@g14g2000cwa.googlegroups.com...

a.. DTC P0100 MAF Sensor Ckt. Insufficient Activity b.. DTC P0101 Mass Air Flow (MAF) Sensor Performance c.. DTC P0102 Mass Air Flow (MAF) Sensor Circuit Low Frequency d.. DTC P0103 Mass Air Flow (MAF) Sensor Circuit High Frequency e.. DTC P0104 Mass Air Flow Circuit Intermittent f.. DTC P0105 MAP Sensor Circuit Insufficient Activity g.. DTC P0106 Manifold Absolute Pressure (MAP) System Performance h.. DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage i.. DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage j.. DTC P0109 Manifold Absolute Pressure Circuit Intermittent k.. DTC P0110 Intake Air Temperature (IAT) Sensor Circuit l.. DTC P0111 Intake Air Temperature (IAT) Sensor Performance m.. DTC P0112 Intake Air Temperature (IAT) Sensor Circuit Low Voltage n.. DTC P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage o.. DTC P0114 Intake Air Temperature Circuit Intermittent p.. DTC P0115 Engine Coolant Temperature (ECT) Sensor Circuit q.. DTC P0116 Engine Coolant Temperature (ECT) Sensor Performance r.. DTC P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage s.. DTC P0118 Engine Coolant Temperature (ECT) Sensor Circuit High Voltage t.. DTC P0119 Engine Coolant Temperature Circuit Intermittent u.. DTC P0120 TP System Performance v.. DTC P0121 TP Sensor Circuit Insufficient Activity w.. DTC P0122 Throttle Position (TP) Sensor Circuit Low Voltage x.. DTC P0123 Throttle Position (TP) Sensor Circuit High Voltage y.. DTC P0124 Throttle Position Sensor 1 Circuit Intermittent z.. DTC P0125 Engine Coolant Temperature (ECT) Insufficient for Closed Loop Fuel Control aa.. DTC P0126 Insufficient ECT for Stable Operation ab.. DTC P0128 Coolant Thermostat ac.. DTC P0130 HO2S Circuit Closed Loop (CL) Performance Bank 1 Sensor 1 ad.. DTC P0131 HO2S Circuit Low Voltage Bank 1 Sensor 1 ae.. DTC P0132 HO2S Circuit High Voltage Bank 1 Sensor 1 af.. DTC P0133 HO2S Slow Response Bank 1 Sensor 1 ag.. DTC P0134 HO2S Circuit Insufficient Activity Bank 1 Sensor 1 ah.. DTC P0135 HO2S Heater Performance Bank 1 Sensor 1 ai.. DTC P0136 HO2S Circuit Bank 1 Sensor 2 aj.. DTC P0137 HO2S Circuit Low Voltage Bank 1 Sensor 2 ak.. DTC P0138 HO2S Circuit High Voltage Bank 1 Sensor 2 al.. DTC P0139 HO2S Slow Response Bank 1 Sensor 2 am.. DTC P0140 HO2S Circuit Insufficient Activity Bank 1 Sensor 2 an.. DTC P0141 HO2S Heater Performance Bank 1 Sensor 2 ao.. DTC P0142 HO2S Circuit Bank 1 Sensor 3 ap.. DTC P0143 HO2S Circuit Low Voltage Bank 1 Sensor 3 aq.. DTC P0144 HO2S Circuit High Voltage Bank 1 Sensor 3 ar.. DTC P0145 HO2S Circuit Bank 1 Sensor 2 Slow Response as.. DTC P0146 HO2S Circuit Insufficient Activity Bank 1 Sensor 3 at.. DTC P0147 HO2S Heater Performance Bank 1 Sensor 3 au.. DTC P0150 HO2S Circuit Closed Loop (CL) Performance Bank 2 Sensor 1 av.. DTC P0150 HO2S Circuit Bank 2 Sensor 1 aw.. DTC P0151 HO2S Circuit Low Voltage Bank 2 Sensor 1 ax.. DTC P0152 HO2S Circuit High Voltage Bank 2 Sensor 1 ay.. DTC P0153 HO2S Slow Response Bank 2 Sensor 1 az.. DTC P0154 HO2S Circuit Insufficient Activity Bank 2 Sensor 1 ba.. DTC P0155 HO2S Heater Performance Bank 2 Sensor 1 bb.. DTC P0156 HO2S Circuit Bank 2 Sensor 2 bc.. DTC P0157 HO2S Circuit Low Voltage Bank 2 Sensor 2 bd.. DTC P0158 HO2S Circuit High Voltage Bank 2 Sensor 2 be.. DTC P0159 HO2S Slow Response Bank 2 Sensor 2 bf.. DTC P0160 HO2S Circuit Insufficient Activity Bank 2 Sensor 2 bg.. DTC P0161 HO2S Heater Performance Bank 2 Sensor 2 bh.. DTC P0162 HO2S Circuit Bank 2 Sensor 3 bi.. DTC P0163 HO2S Circuit Bank 2 Sensor 3 Low Voltage bj.. DTC P0164 HO2S Circuit Bank 2 Sensor 3 High Voltage bk.. DTC P0165 HO2S Circuit Bank 2 Sensor 3 Slow Response bl.. DTC P0166 HO2S Circuit Bank 2 Sensor 3 No Activity Detected bm.. DTC P0167 HO2S Heater Circuit Bank 2 Sensor 3 bn.. DTC P0169 Fuel Composition Sensor bo.. DTC P0170 Fuel Trim Bank 1 bp.. DTC P0171 Fuel Trim System Lean Bank 1 bq.. DTC P0172 Fuel Trim System Rich Bank 1 br.. DTC P0173 Fuel Trim Bank 2 bs.. DTC P0174 Fuel Trim System Lean Bank 2 bt.. DTC P0175 Fuel Trim System Rich Bank 2 bu.. DTC P0176 Fuel Composition Sensor Circuit bv.. DTC P0177 Fuel Composition Sensor Circuit Performance bw.. DTC P0178 Fuel Composition Sensor Circuit Low Voltage bx.. DTC P0179 Fuel Composition Sensor Circuit High Voltage by.. DTC P0180 Fuel Temperature Sensor 1 Circuit bz.. DTC P0181 Fuel Temp. Sensor 1 Circuit Performance ca.. DTC P0182 Fuel Temperature Sensor Circuit Low Voltage cb.. DTC P0183 Fuel Temperature Sensor Circuit High Voltage cc.. DTC P0184 Fuel Temperature Sensor 1 Circuit Intermittent cd.. DTC P0185 Fuel Temperature Sensor 2 Circuit ce.. DTC P0186 Fuel Temp. Sensor 2 Circuit Performance cf.. DTC P0187 Fuel Temperature Sensor 2 Circuit Low Voltage cg.. DTC P0188 Fuel Temperature Sensor 2 Circuit High Voltage ch.. DTC P0189 Fuel Temperature Sensor 2 Circuit Intermittent ci.. DTC P0190 Fuel Rail Pressure Sensor Circuit cj.. DTC P0191 Fuel Rail Pressure Sensor Circuit Performance ck.. DTC P0192 Fuel Rail Pressure Sensor Circuit Low Voltage cl.. DTC P0193 Fuel Rail Pressure Sensor Circuit High Voltage cm.. DTC P0194 Fuel Rail Pressure Sensor Circuit Intermittent cn.. DTC P0195 Engine Oil Temperature Sensor co.. DTC P0196 Engine Oil Temperature Sensor Performance cp.. DTC P0197 Engine Oil Temperature Sensor Low Voltage cq.. DTC P0198 Engine Oil Temperature Sensor High Voltage cr.. DTC P0199 Engine Oil Temperature Sensor Intermittent cs.. DTC P0200 Injector Control Circuit ct.. DTC P0201 Injector 1 Control Circuit cu.. DTC P0202 Injector 2 Control Circuit cv.. DTC P0203 Injector 3 Control Circuit cw.. DTC P0204 Injector 4 Control Circuit cx.. DTC P0205 Injector 5 Control Circuit cy.. DTC P0206 Injector 6 Control Circuit cz.. DTC P0207 Injector 7 Control Circuit da.. DTC P0208 Injector 8 Control Circuit db.. DTC P0209 Injector 9 Control Circuit dc.. DTC P0210 Injector 10 Control Circuit dd.. DTC P0211 Injector 11 Control Circuit de.. DTC P0212 Injector 12 Control Circuit df.. DTC P0213 Cold Start Injector 1 dg.. DTC P0214 Cold Start Injector 2 dh.. DTC P0215 Engine Shutoff Control Circuit di.. DTC P0216 Injection Timing Control Circuit dj.. DTC P0217 Engine Overtemp Condition dk.. DTC P0218 Transmission Fluid Overtemperature dl.. DTC P0219 Engine Overspeed Condition dm.. DTC P0220 APP Sensor 2 Circuit dn.. DTC P0221 APP Sensor 2 Circuit Performance do.. DTC P0222 APP Sensor 2 Circuit Low Voltage dp.. DTC P0223 APP Sensor 2 Circuit High Voltage dq.. DTC P0224 Throttle Position Sensor 2 Intermittent dr.. DTC P0225 APP Sensor 3 Circuit ds.. DTC P0226 APP Sensor 3 Circuit Performance dt.. DTC P0227 APP Sensor 3 Circuit Low Voltage du.. DTC P0228 APP Sensor 3 Circuit High Voltage dv.. DTC P0229 Throttle Position Sensor 3 Intermittent dw.. DTC P0230 Fuel Pump Relay Control Circuit dx.. DTC P0231 Fuel Pump Feedback Circuit Low Voltage dy.. DTC P0232 Fuel Pump Feedback Circuit High Voltage dz.. DTC P0233 Fuel Pump Secondary Circuit Intermittent ea.. DTC P0234 TC Engine Overboost Condition eb.. DTC P0235 Turbocharger Boost Sensor 1 Circuit ec.. DTC P0236 TC Boost System ed.. DTC P0237 TC Boost Sensor Circuit Low Voltage ee.. DTC P0238 TC Boost Sensor Circuit High Voltage ef.. DTC P0239 Turbocharger Boost Sensor 2 Circuit eg.. DTC P0240 Turbocharger Boost Sensor 2 Performance eh.. DTC P0241 Turbocharger Boost Sensor 2 Circuit Low Voltage ei.. DTC P0242 Turbocharger Boost Sensor 2 Circuit High Voltage ej.. DTC P0243 Turbocharger Wastegate Solenoid 1 ek.. DTC P0244 Turbocharger Wastegate Solenoid 1 Performance el.. DTC P0245 Turbocharger Wastegate Solenoid 1 Low Voltage em.. DTC P0246 Turbocharger Wastegate Solenoid 1 High Voltage en.. DTC P0247 Turbocharger Wastegate Solenoid 2 eo.. DTC P0248 Turbocharger Wastegate Solenoid 2 Performance ep.. DTC P0249 Turbocharger Wastegate Solenoid 2 Low Voltage eq.. DTC P0250 Turbocharger Wastegate Solenoid 2 High Voltage er.. DTC P0251 Injection Pump Fuel Metering Control "A" Malfunction (Cam/Rotor/Injector) es.. DTC P0252 Injection Pump Fuel Metering Control "A" Range/Performance (Cam/Rotor/Injector) et.. DTC P0253 Injection Pump Fuel Metering Control "A" Low (Cam/Rotor/Injector) eu.. DTC P0254 Injection Pump Fuel Metering Control "A" High (Cam/Rotor/Injector) ev.. DTC P0255 Injection Pump Fuel Metering Control "A" Intermittent (Cam/Rotor/Injector) ew.. DTC P0256 Injection Pump Fuel Metering Control "B" Malfunction (Cam/Rotor/Injector) ex.. DTC P0257 Injection Pump Fuel Metering Control "B" Range/Performance (Cam/Rotor/Injector) ey.. DTC P0258 Injection Pump Fuel Metering Control "B" Low (Cam/Rotor/Injector) ez.. DTC P0259 Injection Pump Fuel Metering Control "B" High (Cam/Rotor/Injector) fa.. DTC P0260 Injection Pump Fuel Metering Control "B" Intermittent (Cam/Rotor/Injector) fb.. DTC P0261 Cylinder 1 Injector Circuit Low fc.. DTC P0262 Cylinder 1 Injector Circuit High fd.. DTC P0263 Cylinder 1 Contribution/Balance Fault fe.. DTC P0264 Cylinder 2 Injector Circuit Low ff.. DTC P0265 Cylinder 2 Injector Circuit High fg.. DTC P0266 Cylinder 2 Contribution/Balance Fault fh.. DTC P0267 Cylinder 3 Injector Circuit Low fi.. DTC P0268 Cylinder 3 Injector Circuit High fj.. DTC P0269 Cylinder 3 Contribution/Balance Fault fk.. DTC P0270 Cylinder 4 Injector Circuit Low fl.. DTC P0271 Cylinder 4 Injector Circuit High fm.. DTC P0272 Cylinder 4 Contribution/Balance Fault fn.. DTC P0273 Cylinder 5 Injector Circuit Low fo.. DTC P0274 Cylinder 5 Injector Circuit High fp.. DTC P0275 Cylinder 5 Contribution/Balance Fault fq.. DTC P0276 Cylinder 6 Injector Circuit Low fr.. DTC P0277 Cylinder 6 Injector Circuit High fs.. DTC P0278 Cylinder 6 Contribution/Balance Fault ft.. DTC P0279 Cylinder 7 Injector Circuit Low fu.. DTC P0280 Cylinder 7 Injector Circuit High fv.. DTC P0281 Cylinder 7 Contribution/Balance Fault fw.. DTC P0282 Cylinder 8 Injector Circuit Low fx.. DTC P0283 Cylinder 8 Injector Circuit High fy.. DTC P0284 Cylinder 8 Contribution/Balance Fault fz.. DTC P0285 Cylinder 9 Injector Circuit Low ga.. DTC P0286 Cylinder 9 Injector Circuit High gb.. DTC P0287 Cylinder 9 Contribution/Balance Fault gc.. DTC P0288 Cylinder 10 Injector Circuit Low gd.. DTC P0289 Cylinder 10 Injector Circuit High ge.. DTC P0290 Cylinder 10 Contribution/Balance Fault gf.. DTC P0291 Cylinder 11 Injector Circuit Low gg.. DTC P0292 Cylinder 11 Injector Circuit High gh.. DTC P0293 Cylinder 11 Contribution/Balance Fault gi.. DTC P0294 Cylinder 12 Injector Circuit Low gj.. DTC P0295 Cylinder 12 Injector Circuit High gk.. DTC P0296 Cylinder 12 Contribution/Range Fault gl.. DTC P0300 Engine Misfire Detected gm.. DTC P0301 Cylinder 1 Misfire Detected gn.. DTC P0302 Cylinder 2 Misfire Detected go.. DTC P0303 Cylinder 3 Misfire Detected gp.. DTC P0304 Cylinder 4 Misfire Detected gq.. DTC P0305 Cylinder 5 Misfire Detected gr.. DTC P0306 Cylinder 6 Misfire Detected gs.. DTC P0307 Cylinder 7 Misfire Detected gt.. DTC P0308 Cylinder 8 Misfire Detected gu.. DTC P0309 Cylinder 9 Misfire Detected gv.. DTC P0311 Cylinder 11 Misfire Detected gw.. DTC P0312 Cylinder 12 Misfire Detected gx.. DTC P0320 Ignition/Distributor Engine Speed Input Circuit Malfunction gy.. DTC P0321 Ignition/Distributor Engine Speed Input Circuit Range/Performance gz.. DTC P0322 IC Module 4X Reference CKT No Frequency ha.. DTC P0323 Ignition/Distributor Engine Speed Input Circuit Intermittent hb.. DTC P0325 PCM Knock Sensor Circuit hc.. DTC P0326 Knock Sensor CKT Excessive Spark Retard hd.. DTC P0327 Knock Sensor Circuit Low Voltage he.. DTC P0328 Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor) hf.. DTC P0329 Knock Sensor 1 Circuit Intermittent (Bank 1 or Single Sensor) hg.. DTC P0330 Knock Sensor (KS) Circuit Bank 2 hh.. DTC P0331 Knock Sensor 2 Circuit Range/Performance (Bank 2) hi.. DTC P0332 Knock Sensor 2 Circuit Low Input (Bank 2) hj.. DTC P0333 Knock Sensor 2 Circuit High Input (Bank 2) hk.. DTC P0334 Knock Sensor 2 Circuit Intermittent (Bank 2) hl.. DTC P0335 CKP Sensor A Circuit Performance hm.. DTC P0336 Crankshaft Position (CKP) Sensor A Performance hn.. DTC P0337 Crankshaft Position (CKP) Sensor Circuit Low Duty Cycle ho.. DTC P0338 Crankshaft Position (CKP) Sensor Circuit High Duty Cycle hp.. DTC P0339 Crankshaft Position (CKP) Sensor Circuit Intermittent hq.. DTC P0340 Camshaft Position (CMP) Sensor Circuit hr.. DTC P0341 Camshaft Position (CMP) Sensor Performance hs.. DTC P0342 Camshaft Position Sensor Circuit Low Input ht.. DTC P0343 Camshaft Position Sensor Circuit High Input hu.. DTC P0344 Camshaft Position Sensor Circuit Intermittent hv.. DTC P0350 Ignition Coil Primary/Secondary Circuit Malfunction hw.. DTC P0351 Ignition Coil 1 Control Circuit hx.. DTC P0352 Ignition Coil 2 Control Circuit hy.. DTC P0353 Ignition Coil 3 Control Circuit hz.. DTC P0354 Ignition Coil 4 Control Circuit ia.. DTC P0355 Ignition Coil 5 Control Circuit ib.. DTC P0356 Ignition Coil 6 Control Circuit ic.. DTC P0357 Ignition Coil 7 Control Circuit id.. DTC P0358 Ignition Coil 8 Control Circuit ie.. DTC P0359 Ignition Coil I Primary/Secondary Circuit Malfunction if.. DTC P0360 Ignition Coil J Primary/Secondary Circuit Malfunction ig.. DTC P0361 Ignition Coil K Primary/Secondary Circuit Malfunction ih.. DTC P0362 Ignition Coil L Primary/Secondary Circuit Malfunction ii.. DTC P0370 Timing Reference High Resolution Signal A Malfunction ij.. DTC P0371 IC 24X Reference CKT Too Many Pulses ik.. DTC P0372 IC 24X Reference Circuit Missing Pulses il.. DTC P0373 Timing Reference High Resolution Signal A Intermittent/Erratic Pulses im.. DTC P0374 Timing Reference High Resolution Signal A No Pulses in.. DTC P0375 Timing Reference High Resolution Signal B Malfunction io.. DTC P0376 Timing Reference High Resolution Signal B Too Many Pulses ip.. DTC P0377 Timing Reference High Resolution Signal B Too Few Pulses iq.. DTC P0378 Timing Reference High Resolution Signal B Intermittent/Erratic Pulses ir.. DTC P0379 Timing Reference High Resolution Signal B No Pulses

If it's really lean and since you can keep it running by jockeying throttle opening it might be throttle position sensor (TPI) or, and less likely, an idle air control (IAC) that's wide open. Knowing the fuel pressure on the injector rail (static and running) would be handy info. How about a loose connector or broken wire in the injector harness? (low current shortening the fuel bursts).

I'd tend to think that at this struggling stage of operation, the ECM hasn't brought the O2 sensor into the loop yet. (IIRC, that's about 104 deg on the '89)

It seems like this would be a

PJ wrote "I'd tend to think that at this struggling stage of operation, the ECM hasn't brought the O2 sensor into the loop yet. (IIRC, that's about

Thanks for the ideas, I like the injector harness idea, I will investigate, and the TPS - I think I should be able to trouble shoot that with a multi meter. That could expalin a lot of what is happening. I did manage to bring the coolant temp up to about 160 so it should have been in to the 'loop' by then. Thanks also to 'Dad' for the codes. I think this car has only OBD 1 so I am not sure how much crossover there is. I am trying to get a crash course in C4 maintainence here, I have owned this car for 10 yrs. and besides a bad IAC and one relay (burnoff for O2 sensor) it has run like a watch the whole time (total 56K miles). Not much incentive to delve into tuning issues on it. This malady was very sudden onset, brought on by a bad battery, which I should have mentioned earlier. When the battery was replaced the car "woke up" doing this.

Again, thanks all for the tips and hints Dave G.

No I don't.

After 49 years driving Corvettes one day on a flatbed doesn't dampen my desires much. There was a burnt out ballast on a '61 that let me down once but I jumpered it out with a hair pin until I got home. The sad part about that is that she, the hair pin and the '61 are all gone now. As a working set they were great, but so goes life. Time changes allot of things, my '57 cost lest than $4,000, and the '98 cost less than $40,000, gas was .28 cents and----------- you get the drift.

Look at the bright side, you're not gone.